1
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Toxopeus J, Dowle EJ, Andaloori L, Ragland GJ. Variation in Thermal Sensitivity of Diapause Development among Individuals and over Time Predicts Life History Timing in a Univoltine Insect. Am Nat 2024; 203:E200-E217. [PMID: 38781522 DOI: 10.1086/729515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
AbstractPhysiological time is important for understanding the development and seasonal timing of ectothermic animals but has largely been applied to developmental processes that occur during spring and summer, such as morphogenesis. There is a substantial knowledge gap in the relationship between temperature and development during winter, a season that is increasingly impacted by climate change. Most temperate insects overwinter in diapause, a developmental process with little obvious morphological change. We used principles from the physiological time literature to measure and model the thermal sensitivity of diapause development rate in the apple maggot fly Rhagoletis pomonella, a univoltine fly whose diapause duration varies substantially within and among populations. We show that diapause duration can be predicted by modeling a relationship between temperature and development rate that is shifted toward lower temperatures compared with typical models of morphogenic, nondiapause development. However, incorporating interindividual variation and ontogenetic variation in the temperature-to-development rate relationship was critical for accurately predicting fly emergence, as diapause development proceeded more quickly at high temperatures later in diapause. We conclude that the conceptual framework may be flexibly applied to other insects and discuss possible mechanisms of diapause timers and implications for phenology with warming winters.
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2
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Black EN, Blair JD, van der Burg KRL, Marshall KE. Crowd-sourced observations of a polyphagous moth reveal evidence of allochronic speciation varying along a latitudinal gradient. PLoS One 2023; 18:e0288415. [PMID: 37440520 DOI: 10.1371/journal.pone.0288415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
Allochronic speciation, where reproductive isolation between populations of a species is facilitated by a difference in reproductive timing, depends on abiotic factors such as seasonality and biotic factors such as diapause intensity. These factors are strongly influenced by latitudinal trends in climate, so we hypothesized that there is a relationship between latitude and divergence among populations separated by life history timing. Hyphantria cunea (the fall webworm), a lepidopteran defoliator with red and black colour morphs, is hypothesized to be experiencing an incipient allochronic speciation. However, given their broad geographic range, the strength of allochronic speciation may vary across latitude. We annotated >11,000 crowd-sourced observations of fall webworm to model geographic distribution, phenology, and differences in colour phenotype between morphs across North America. We found that red and black morph life history timing differs across North America, and the phenology of morphs diverges more in warmer climates at lower latitudes. We also found some evidence that the colour phenotype of morphs also diverges at lower latitudes, suggesting reduced gene flow between colour morphs. Our results demonstrate that seasonality in lower latitudes may increase the strength of allochronic speciation in insects, and that the strength of sympatric speciation can vary along a latitudinal gradient. This has implications for our understanding of broad-scale speciation events and trends in global biodiversity.
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Affiliation(s)
- Emily N Black
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jarrett D Blair
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Karin R L van der Burg
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katie E Marshall
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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3
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Lackey ACR, Murray AC, Mirza NA, Powell THQ. The role of sexual isolation during rapid ecological divergence: Evidence for a new dimension of isolation in Rhagoletis pomonella. J Evol Biol 2023. [PMID: 37173822 DOI: 10.1111/jeb.14179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 03/05/2023] [Accepted: 03/23/2023] [Indexed: 05/15/2023]
Abstract
The pace of divergence and likelihood of speciation often depends on how and when different types of reproductive barriers evolve. Questions remain about how reproductive isolation evolves after initial divergence. We tested for the presence of sexual isolation (reduced mating between populations due to divergent mating preferences and traits) in Rhagoletis pomonella flies, a model system for incipient ecological speciation. We measured the strength of sexual isolation between two very recently diverged (~170 generations) sympatric populations, adapted to different host fruits (hawthorn and apple). We found that flies from both populations were more likely to mate within than between populations. Thus, sexual isolation may play an important role in reducing gene flow allowed by early-acting ecological barriers. We also tested how warmer temperatures predicted under climate change could alter sexual isolation and found that sexual isolation was markedly asymmetric under warmer temperatures - apple males and hawthorn females mated randomly while apple females and hawthorn males mated more within populations than between. Our findings provide a window into the early speciation process and the role of sexual isolation after initial ecological divergence, in addition to examining how environmental conditions could shape the likelihood of further divergence.
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Affiliation(s)
- Alycia C R Lackey
- University of Louisville, Louisville, Kentucky, USA
- Binghamton University, Binghamton, New York, USA
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4
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McIntyre T, Andaloori L, Hood GR, Feder JL, Hahn DA, Ragland GJ, Toxopeus J. Cold tolerance and diapause within and across trophic levels: Endoparasitic wasps and their fly host have similar phenotypes. JOURNAL OF INSECT PHYSIOLOGY 2023; 146:104501. [PMID: 36921838 DOI: 10.1016/j.jinsphys.2023.104501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/05/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Abstract
Low temperatures associated with winter can limit the survival of organisms, especially ectotherms whose body temperature is similar to their environment. However, there is a gap in understanding how overwintering may vary among groups of species that interact closely, such as multiple parasitoid species that attack the same host insect. Here, we investigate cold tolerance and diapause phenotypes in three endoparasitoid wasps of the apple maggot fly Rhagoletis pomonella (Diptera: Tephritidae): Utetes canaliculatus, Diachasma alloeum, and Diachasmimorpha mellea (Hymenoptera: Braconidae). Using a combination of respirometry and eclosion tracking, we found that all three wasp species exhibited the same three diapause duration phenotypes as the fly host. Weak (short duration) diapause was rare, with <5 % of all three wasp species prematurely terminating diapause at 21 °C. Most D.mellea (93 %) entered a more intense (longer duration) diapause that did not terminate within 100 d at this warm temperature. The majority of U.canaliculatus (92 %) and D. alloeum (72 %) averted diapause (non-diapause) at 21 °C. There was limited interspecific variation in acute cold tolerance among the three wasp species: wasps and flies had similarly high survival (>87 %) following exposure to extreme low temperatures (-20 °C) as long as their body fluids did not freeze. The three wasp species also displayed little interspecific variation in survival following prolonged exposure to mild chilling of 8 or more weeks at 4 °C. Our study thus documents a remarkable conservation of cold tolerance and diapause phenotypes within and across trophic levels.
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Affiliation(s)
- Trinity McIntyre
- Department of Biology, St. Francis Xavier University, 2321 Notre Dame Ave, Antigonish NS B2G 2W5, Canada
| | - Lalitya Andaloori
- Department of Integrative Biology, University of Colorado Denver, 1151 Arapahoe St., Denver CO 80204, USA
| | - Glen R Hood
- Department of Biological Sciences, Wayne State University, 4841 Cass Avenue, Detroit MI 48201, USA
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Galvin Life Sciences Center, Notre Dame IN 46556, USA
| | - Daniel A Hahn
- Entomology and Nematology Department, University of Florida, 1881 Natural Area Drive, Gainesville FL 32611, USA
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado Denver, 1151 Arapahoe St., Denver CO 80204, USA
| | - Jantina Toxopeus
- Department of Biology, St. Francis Xavier University, 2321 Notre Dame Ave, Antigonish NS B2G 2W5, Canada.
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5
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Kharva H, Feder JL, Hahn DA, Olsson SB. Rapid brain development and reduced neuromodulator titres correlate with host shifts in Rhagoletis pomonella. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220962. [PMID: 36117862 PMCID: PMC9449811 DOI: 10.1098/rsos.220962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 08/16/2022] [Indexed: 05/27/2023]
Abstract
Host shifts are considered a key generator of insect biodiversity. For insects, adaptation to new host plants often requires changes in larval/pupal development and adult behavioural preference toward new hosts. Neurochemicals play key roles in both development and behaviour and therefore provide a potential source for such synchronization. Here, we correlated life-history timing, brain development and corresponding levels of 14 neurochemicals in Rhagoletis pomonella (Diptera: Tephritidae), a species undergoing ecological speciation through an ongoing host shift from hawthorn to apple fruit. These races exhibit differences in pupal diapause timing as well as adult behavioural preference with respect to their hosts. This difference in behavioural preference is coupled with differences in neurophysiological response to host volatiles. We found that apple race pupae exhibited adult brain morphogenesis three weeks faster after an identical simulated winter than the hawthorn race, which correlated with significantly lower titres of several neurochemicals. In some cases, particularly biogenic amines, differences in titres were reflected in the mature adult stage, when host preference is exhibited. In summary, life-history timing, neurochemical titre and brain development can be coupled in this speciating system, providing new hypotheses for the origins of new species through host shifts.
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Affiliation(s)
- Hinal Kharva
- Naturalist-Inspired Chemical Ecology lab, National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore 560065, India
- School of Life Sciences, The University of Trans-Disciplinary Health Sciences and Technology, 74/2, Jarakabande Kaval, Post Attur via Yelahanka, Bangalore 560064, India
| | - Jeffrey L. Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Daniel A. Hahn
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA
| | - Shannon B. Olsson
- Naturalist-Inspired Chemical Ecology lab, National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore 560065, India
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6
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Genotoxicity Set Up in Artemia franciscana Nauplii and Adults Exposed to Phenanthrene, Naphthalene, Fluoranthene, and Benzo(k)fluoranthene. WATER 2022. [DOI: 10.3390/w14101594] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) consist of a group of over 100 different organic compounds mainly generated by anthropogenic activities. Because of their low water solubility, they tend to be accumulated in sediment, where their degradation rate is very low. Few studies have been carried out so far to investigate the effects of PAHs on Artemia franciscana. Artemia is easy to manage at laboratory scale, but it is not a sensitive biological model considering the traditional endpoints (i.e., mortality). In addition to evaluating the lethality on nauplii and adults of A. franciscana after 24 and 48 h, we focused on the genotoxicity to investigate the potential effects of phenanthrene (PHE), naphthalene (NAP), fluoranthene (FLT), and benzo(k)fluoranthene (BkF). Results showed that FLT was the most toxic both for nauplii and adults after 48 h of exposure. Real-time qPCR showed that all toxicants, including BkF, which had no negative effects on the survival of the crustacean, were able to switch the gene expression of all nine genes. This work has important ecological implications, especially on contaminated sediment assessment considering that PAHs represent the most abundant organic group of compounds in marine environment, opening new perspectives in understanding the molecular pathways activated by crustaceans.
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7
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Yee WL, Goughnour RB, Forbes AA, Milnes JM, Feder JL. Sensitivities to Chill Durations and No-Chill Temperatures Regulating Eclosion Responses Differ Between Rhagoletis zephyria (Diptera: Tephritidae) and its Braconid Parasitoids (Hymenoptera: Braconidae). ENVIRONMENTAL ENTOMOLOGY 2022; 51:440-450. [PMID: 35137031 DOI: 10.1093/ee/nvac009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Seasonal temperatures select for eclosion timing of temperate insects and their parasitoids. In western North America, the fruit fly Rhagoletis zephyria Snow (Diptera: Tephritidae) is parasitized by the hymenopterous wasps Utetes lectoides (Gahan), an egg parasite, and Opius downesi Gahan, a larval parasite (both Braconidae). Eclosion of wasps should be timed with the presence of susceptible fly stages, but reports indicate U. lectoides ecloses in the absence of flies under no-chill conditions. Based on this, we tested the hypotheses that chill durations and no-chill temperatures both differentially regulate eclosion times of R. zephyria and its parasitic wasps. When fly puparia were chilled at ~3°C for 130-180 d, U. lectoides and O. downesi always eclosed on average later than flies. However, after 180-d chill, flies eclosed on average earlier than after 130- and 150-d chill, whereas eclosion times of U. lectoides and O. downesi were less or not affected by chill duration. When fly puparia were exposed to 20-22°C (no chill), U. lectoides eclosed before flies, with 88.9% of U. lectoides versus only 0.61% of flies eclosing. Taken together, findings show that eclosion times of flies are more sensitive to changes in chill duration than those of wasps. Flies are less sensitive than wasps to no-chill in that most flies do not respond by eclosing after no-chill while most wasps do. Our results suggest that shorter winters and longer summers due to climate change could cause mismatches in eclosion times of flies and wasps, with potentially significant evolutionary consequences.
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Affiliation(s)
- Wee L Yee
- USDA-ARS, Temperate Tree Fruit & Vegetable Research Unit, 5230 Konnowac Pass Road, Wapato, WA 98951, USA
| | - Robert B Goughnour
- Washington State University Extension, 1919 NE 78th Street, Vancouver, WA 98665, USA
| | - Andrew A Forbes
- Department of Biology, the University of Iowa, 434A Biology Building, Iowa City, IA 52242, USA
| | - Joshua M Milnes
- Washington State Department of Agriculture - Plant Protection Division, 21 North 1st Avenue, Suite 103, Yakima, WA 98902, USA
| | - Jeffrey L Feder
- Department of Biological Sciences, Galvin Life Sciences Building, University of Notre Dame, Notre Dame, IN 46556, USA
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8
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Rull J, Lasa R, Aguas-Lanzagorta S, Aluja M. Host plant stimuli effects on survival and duration of dormancy of Rhagoletis zoqui, Rhagoletis completa (Diptera: Tephritidae) and associated parasitoids. BULLETIN OF ENTOMOLOGICAL RESEARCH 2022; 112:1-9. [PMID: 35264259 DOI: 10.1017/s0007485321000778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Tephritid fruit flies in the genus Rhagoletis bridge between predictable periods of fruit availability by becoming dormant. To cope with acyclic unpredictable events (e.g., frost, mast seeding, etc), a proportion of the population can undergo prolonged dormancy. In the case of walnut infesting Rhagoletis, host plant-derived cues such as juglone soil concentration vary seasonally in predictable patterns. Here, we examined the effects of host plant parts and derived compounds on emergence rates and dormancy duration of Rhagoletis completa (Cresson), Rhagoletis zoqui (Bush) (Diptera: Tephritidae), and associated parasitoids. Pupae of both species were exposed to walnut leaves, fruit, or fruit and leaves and compared to a control. In a second experiment, R. zoqui were exposed to 10 mg l-1 of juglone applied to pupation medium during four consecutive 4-week time periods under variable combinations of temperature and frequency of exposure. Overall, the presence of fruit resulted in greater overwintering survival of R. completa but had no effect on the duration of dormancy of either fly species. Application of juglone over two consecutive periods produced greater mortality of R. zoqui than the control. Three parasitoid species emerged from R. completa and one from R. zoqui. Duration of dormancy for parasitoids was longer than that of fly hosts. Regardless of treatment, 13.3-18.4% of R. completa pupae and 1.3-2.8% R. zoqui engaged in prolonged (>year) dormancy. Our results indicate that host plant derived cues have little or no effect on survival and duration of dormancy of walnut infesting Rhagoletis, and at the tested concentration juglone is toxic to R. zoqui pupae. Testing the effect of juglone at lower concentrations is necessary to rule out its role as an environmental cue for regulation of dormancy. So far, host plant fruiting phenology appears to play a greater role than host plant derived cues in selecting for fly eclosion times.
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Affiliation(s)
- J Rull
- PROIMI Biotecnología-CONICET, LIEMEN-División Control Biológico de Plagas, Av. Belgrano y Pje. Caseros, T4001MVB San Miguel de Tucumán, Tucumán, Argentina
| | - R Lasa
- Instituto de Ecología, A.C., - INECOL, Clúster Científico y Tecnológico BioMimic®, Carretera Antigua a Coatepec 351, Colonia el Haya, CP 91073 Xalapa, Veracruz, México
| | - S Aguas-Lanzagorta
- Instituto de Ecología, A.C., - INECOL, Clúster Científico y Tecnológico BioMimic®, Carretera Antigua a Coatepec 351, Colonia el Haya, CP 91073 Xalapa, Veracruz, México
| | - M Aluja
- Instituto de Ecología, A.C., - INECOL, Clúster Científico y Tecnológico BioMimic®, Carretera Antigua a Coatepec 351, Colonia el Haya, CP 91073 Xalapa, Veracruz, México
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9
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The Build-Up of Population Genetic Divergence along the Speciation Continuum during a Recent Adaptive Radiation of Rhagoletis Flies. Genes (Basel) 2022; 13:genes13020275. [PMID: 35205320 PMCID: PMC8872456 DOI: 10.3390/genes13020275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 02/05/2023] Open
Abstract
New species form through the evolution of genetic barriers to gene flow between previously interbreeding populations. The understanding of how speciation proceeds is hampered by our inability to follow cases of incipient speciation through time. Comparative approaches examining different diverging taxa may offer limited inferences, unless they fulfill criteria that make the comparisons relevant. Here, we test for those criteria in a recent adaptive radiation of the Rhagoletis pomonella species group (RPSG) hypothesized to have diverged in sympatry via adaptation to different host fruits. We use a large-scale population genetic survey of 1568 flies across 33 populations to: (1) detect on-going hybridization, (2) determine whether the RPSG is derived from the same proximate ancestor, and (3) examine patterns of clustering and differentiation among sympatric populations. We find that divergence of each in-group RPSG taxon is occurring under current gene flow, that the derived members are nested within the large pool of genetic variation present in hawthorn-infesting populations of R. pomonella, and that sympatric population pairs differ markedly in their degree of genotypic clustering and differentiation across loci. We conclude that the RPSG provides a particularly robust opportunity to make direct comparisons to test hypotheses about how ecological speciation proceeds despite on-going gene flow.
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10
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Matsubayashi KW, Yamaguchi R. The speciation view: Disentangling multiple causes of adaptive and nonadaptive radiation in terms of speciation. POPUL ECOL 2021. [DOI: 10.1002/1438-390x.12103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kei W. Matsubayashi
- Faculty of Arts and Science, Kyushu University Nishi‐ku Motooka 744 Fukuoka Kyushu Japan
| | - Ryo Yamaguchi
- Department of Advanced Transdisciplinary Sciences Hokkaido University Sapporo Hokkaido Japan
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11
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Aguirre-Ramirez E, Velasco-Cuervo S, Toro-Perea N. Genomic Traces of the Fruit Fly Anastrepha obliqua Associated with Its Polyphagous Nature. INSECTS 2021; 12:1116. [PMID: 34940204 PMCID: PMC8704581 DOI: 10.3390/insects12121116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/24/2021] [Accepted: 11/27/2021] [Indexed: 12/23/2022]
Abstract
Anastrepha obliqua (Macquart) (Diptera: Tephritidae) is an important pest in the neotropical region. It is considered a polyphagous insect, meaning it infests plants of different taxonomic families and readily colonizes new host plants. The change to new hosts can lead to diversification and the formation of host races. Previous studies investigating the effect of host plants on population structure and selection in Anastrepha obliqua have focused on the use of data from the mitochondrial DNA sequence and microsatellite markers of nuclear DNA, and there are no analyses at the genomic level. To better understand this issue, we used a pooled restriction site-associated DNA sequencing (pooled RAD-seq) approach to assess genomic differentiation and population structure across sympatric populations of Anastrepha obliqua that infest three host plants-Spondias purpurea (red mombin), Mangifera indica (mango) of the family Anacardiaceae and Averrhoa carambola (carambola) of the family Oxalidaceae-in sympatric populations of the species Anastrepha obliqua of Inter-Andean Valley of the Cauca River in southwestern Colombia. Our results show genomic differentiation of populations from carambola compared to mango and red mombin populations, but the genetic structure was mainly established by geography rather than by the host plant. On the other hand, we identified 54 SNPs in 23 sequences significantly associated with the use of the host plant. Of these 23 sequences, we identified 17 candidate genes and nine protein families, of which four protein families are involved in the nutrition of these flies. Future studies should investigate the adaptive processes undergone by phytophagous insects in the Neotropics, using fruit flies as a model and state-of-the-art molecular tools.
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Affiliation(s)
- Elkin Aguirre-Ramirez
- Grupo de Estudios Ecogenéticos y Biología Molecular, Departamento de Biología, Universidad del Valle, Cali 760032, Colombia; (S.V.-C.); (N.T.-P.)
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12
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Calvert MB, Doellman MM, Feder JL, Hood GR, Meyers P, Egan SP, Powell THQ, Glover MM, Tait C, Schuler H, Berlocher SH, Smith JJ, Nosil P, Hahn DA, Ragland GJ. Genomically correlated trait combinations and antagonistic selection contributing to counterintuitive genetic patterns of adaptive diapause divergence in Rhagoletis flies. J Evol Biol 2021; 35:146-163. [PMID: 34670006 DOI: 10.1111/jeb.13952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 10/08/2021] [Accepted: 10/15/2021] [Indexed: 11/27/2022]
Abstract
Adaptation to novel environments can result in unanticipated genomic responses to selection. Here, we illustrate how multifarious, correlational selection helps explain a counterintuitive pattern of genetic divergence between the recently derived apple- and ancestral hawthorn-infesting host races of Rhagoletis pomonella (Diptera: Tephritidae). The apple host race terminates diapause and emerges as adults earlier in the season than the hawthorn host race, to coincide with the earlier fruiting phenology of their apple hosts. However, alleles at many loci associated with later emergence paradoxically occur at higher frequencies in sympatric populations of the apple compared to the hawthorn race. We present genomic evidence that historical selection over geographically varying environmental gradients across North America generated genetic correlations between two life history traits, diapause intensity and diapause termination, in the hawthorn host race. Moreover, the loci associated with these life history traits are concentrated in genomic regions in high linkage disequilibrium (LD). These genetic correlations are antagonistic to contemporary selection on local apple host race populations that favours increased initial diapause depth and earlier, not later, diapause termination. Thus, the paradox of apple flies appears due, in part, to pleiotropy or linkage of alleles associated with later adult emergence and increased initial diapause intensity, the latter trait strongly selected for by the earlier phenology of apples. Our results demonstrate how understanding of multivariate trait combinations and the correlative nature of selective forces acting on them can improve predictions concerning adaptive evolution and help explain seemingly counterintuitive patterns of genetic diversity in nature.
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Affiliation(s)
- McCall B Calvert
- Department of Integrative Biology, University of Colorado Denver, Denver, Colorado, USA
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA.,Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana, USA.,Advanced Diagnostics and Therapeutics Initiative, University of Notre Dame, Notre Dame, Indiana, USA
| | - Glen R Hood
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA.,Department of Biosciences, Rice University, Houston, Texas, USA.,Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Peter Meyers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Scott P Egan
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA.,Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana, USA.,Advanced Diagnostics and Therapeutics Initiative, University of Notre Dame, Notre Dame, Indiana, USA.,Department of Biosciences, Rice University, Houston, Texas, USA
| | - Thomas H Q Powell
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA.,Department of Biological Sciences, Binghamton University (State University of New York), Binghamton, New York, USA
| | - Mary M Glover
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Cheyenne Tait
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Hannes Schuler
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA.,Faculty of Science and Technology, Free University of Bozen-Bolzano, Bozen, Italy
| | - Stewart H Berlocher
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - James J Smith
- Department of Entomology, Lyman Briggs College, Michigan State University, East Lansing, Michigan, USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,CEFE, CNRS, EPHE, IRD, Univ Montpellier, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Daniel A Hahn
- Department of Entomology and Nematology, University of Florida, Gainesville, Florida, USA
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado Denver, Denver, Colorado, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA.,Advanced Diagnostics and Therapeutics Initiative, University of Notre Dame, Notre Dame, Indiana, USA
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13
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Yee WL, Forbes AA, Feder JL. Contrast in Post-Chill Eclosion Time Strategies Between Two Specialist Braconid Wasps (Hymenoptera: Braconidae) Attacking Rhagoletis Flies (Diptera: Tephritidae) in Western North America. ENVIRONMENTAL ENTOMOLOGY 2021; 50:1173-1186. [PMID: 34387323 DOI: 10.1093/ee/nvab080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Indexed: 06/13/2023]
Abstract
Parasitoids comprise a speciose insect group, displaying a wide array of life history strategies. In the Pacific Northwest of the United States, the tephritid fruit flies Rhagoletis tabellaria (Fitch) and Rhagoletis indifferens Curran infest red osier dogwood, Cornus sericea L. (Cornaceae), and bitter cherry, Prunus emarginata (Douglas ex Hooker) Eaton (Rosaceae), respectively. The flies are parasitized by different braconid wasps at different life stages; Utetes tabellariae (Fischer) oviposits into R. tabellaria eggs, whereas Diachasma muliebre (Muesebeck) oviposits into R. indifferens larvae feeding in cherries. Because Rhagoletis only have one major generation a year and the wasps attack temporally distinct fly life stages, we predicted that eclosion times of U. tabellariae should more closely follow that of its host than the larval-attacking D. muliebre. As predicted, U. tabellariae eclosed on average 6.0-12.5 d later than R. tabellaria, whereas D. muliebre eclosed on average 32.1 d after R. indifferens. Unexpectedly, however, longer chill duration differentially affected the systems; longer overwinters minimally influenced eclosion times of R. tabellaria and U. tabellariae but caused earlier eclosion of both R. indifferens and D. muliebre. Results imply that in temperate regions, diapause timing in braconid wasps evolves in response to both host life stage attacked and fly eclosion characteristics, possibly reflecting differential effects of winter on host plant fruiting phenology. Differences in phenological sensitivity of the lower host plant trophic level to variation in environmental conditions may have cascading effects, sequentially and differentially affecting eclosion times in higher frugivore (fly) and parasitoid (wasp) trophic levels.
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Affiliation(s)
- Wee L Yee
- USDA-ARS, Temperate Tree Fruit and Vegetable Research Unit, 5230 Konnowac Pass Rd, Wapato, WA 98951, USA
| | - Andrew A Forbes
- Department of Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Jeffrey L Feder
- Department Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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14
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Lebenzon JE, Torson AS, Sinclair BJ. Diapause differentially modulates the transcriptomes of fat body and flight muscle in the Colorado potato beetle. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 40:100906. [PMID: 34509173 DOI: 10.1016/j.cbd.2021.100906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/05/2021] [Accepted: 08/21/2021] [Indexed: 12/21/2022]
Abstract
Many temperate insects, such as the Colorado potato beetle, enter diapause in winter, during which they arrest their development, suppress their metabolic rate and have high stress tolerance. Diapause phenotypes can be transcriptionally regulated, however many studies to date report only whole animal gene expression rather than tissue-specific processes during diapause. We used RNA-seq to measure gene expression in fat body and flight muscle of diapausing and non-diapausing beetles. We used differential expression and GO enrichment analyses to evaluate longstanding hypotheses about the mechanisms that drive arrested development, changes in energy metabolism, and increased stress tolerance during diapause. We found evidence of G2/M cell cycle arrest, juvenile hormone catabolism, increased antioxidant metabolism, epigenetic modification, transposable element regulation, and cytoskeletal remodeling in both the fat body and flight muscle of diapausing beetles. Beetles differentially modulated the fat body and flight muscle transcriptomes during diapause with fat body playing a larger role in the hypoxia response and immunity, whereas flight muscle had higher abundance of transcripts related to the chaperone response and proteostasis. Our transcriptome provides evidence for distinct roles and responses of fat body and flight muscle during diapause in the Colorado potato beetle, and we provide testable hypotheses for biological processes that appear to drive diapause phenotypes in insects.
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Affiliation(s)
- Jacqueline E Lebenzon
- Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada.
| | - Alex S Torson
- Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada.
| | - Brent J Sinclair
- Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada.
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15
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Inskeep KA, Doellman MM, Powell THQ, Berlocher SH, Seifert NR, Hood GR, Ragland GJ, Meyers PJ, Feder JL. Divergent diapause life history timing drives both allochronic speciation and reticulate hybridization in an adaptive radiation of Rhagoletis flies. Mol Ecol 2021; 31:4031-4049. [PMID: 33786930 DOI: 10.1111/mec.15908] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/01/2021] [Accepted: 03/15/2021] [Indexed: 12/18/2022]
Abstract
Divergent adaptation to new ecological opportunities can be an important factor initiating speciation. However, as niches are filled during adaptive radiations, trait divergence driving reproductive isolation between sister taxa may also result in trait convergence with more distantly related taxa, increasing the potential for reticulated gene flow across the radiation. Here, we demonstrate such a scenario in a recent adaptive radiation of Rhagoletis fruit flies, specialized on different host plants. Throughout this radiation, shifts to novel hosts are associated with changes in diapause life history timing, which act as "magic traits" generating allochronic reproductive isolation and facilitating speciation-with-gene-flow. Evidence from laboratory rearing experiments measuring adult emergence timing and genome-wide DNA-sequencing surveys supported allochronic speciation between summer-fruiting Vaccinium spp.-infesting Rhagoletis mendax and its hypothesized and undescribed sister taxon infesting autumn-fruiting sparkleberries. The sparkleberry fly and R. mendax were shown to be genetically discrete sister taxa, exhibiting no detectable gene flow and allochronically isolated by a 2-month average difference in emergence time corresponding to host availability. At sympatric sites across the southern USA, the later fruiting phenology of sparkleberries overlaps with that of flowering dogwood, the host of another more distantly related and undescribed Rhagoletis taxon. Laboratory emergence data confirmed broadly overlapping life history timing and genomic evidence supported on-going gene flow between sparkleberry and flowering dogwood flies. Thus, divergent phenological adaptation can drive the initiation of reproductive isolation, while also enhancing genetic exchange across broader adaptive radiations, potentially serving as a source of novel genotypic variation and accentuating further diversification.
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Affiliation(s)
- Katherine A Inskeep
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Thomas H Q Powell
- Department of Biological Sciences, Binghamton University (State University of New York), Binghamton, NY, USA
| | - Stewart H Berlocher
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Nicholas R Seifert
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Glen R Hood
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
| | - Peter J Meyers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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16
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Toxopeus J, Gadey L, Andaloori L, Sanaei M, Ragland GJ. Costs of averting or prematurely terminating diapause associated with slow decline of metabolic rates at low temperature. Comp Biochem Physiol A Mol Integr Physiol 2021; 255:110920. [PMID: 33582264 DOI: 10.1016/j.cbpa.2021.110920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/25/2021] [Accepted: 02/08/2021] [Indexed: 12/28/2022]
Abstract
Diapause, a form of insect dormancy, generally facilitates overwintering by increasing cold tolerance and decreasing energy drain at high temperatures via metabolic rate suppression. Averting or terminating diapause prior to winter is generally assumed to be a lethal phenotype. However, low temperature acclimation can also increase cold tolerance and decrease metabolic rates. Here, we tested the hypothesis that non- and post-diapause individuals in a cold-induced quiescence can achieve a diapause-like phenotype, compensating for the potential costs of averting diapause. We tested this in the apple maggot fly Rhagoletis pomonella, which typically overwinters in the soil as a diapause pupa, but can avert diapause (non-diapause) or terminate diapause early ('weak diapause') when reared at warm temperatures. Metabolic rates were initially higher in non- and post-diapause than diapause pupae at high (25 °C) and low (4 °C) temperatures, but quiescent non- and post-diapause pupae achieved diapause-like metabolic rates slowly over time when incubated at 4 °C for several weeks. We found that diapause and quiescent pupae were freeze-avoidant and had similar tolerance of extreme low temperatures (cooling to c. -18 °C) following 8 weeks acclimation at 4 °C. Despite high tolerance of subzero temperatures, quiescent pupae did not survive well when chilled for prolonged periods (8 weeks or more) at 4 °C. We conclude that cold acclimation can only partially compensate for costs associated with aversion or premature termination of diapause, and that energy drain at low (not just high) temperatures likely contributes to chilling mortality in quiescent insects.
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Affiliation(s)
- Jantina Toxopeus
- Department of Integrative Biology, University of Colorado, Denver, 1151 Arapahoe St, Denver, CO, 80204, United States.
| | - Lahari Gadey
- Department of Integrative Biology, University of Colorado, Denver, 1151 Arapahoe St, Denver, CO, 80204, United States.
| | - Lalitya Andaloori
- Department of Integrative Biology, University of Colorado, Denver, 1151 Arapahoe St, Denver, CO, 80204, United States.
| | - Matin Sanaei
- Department of Integrative Biology, University of Colorado, Denver, 1151 Arapahoe St, Denver, CO, 80204, United States.
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado, Denver, 1151 Arapahoe St, Denver, CO, 80204, United States.
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17
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Salazar-Jaramillo L, Wertheim B. Does Drosophila sechellia escape parasitoid attack by feeding on a toxic resource? PeerJ 2021; 9:e10528. [PMID: 33505786 PMCID: PMC7796662 DOI: 10.7717/peerj.10528] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
Host shifts can drastically change the selective pressures that animals experience from their environment. Drosophila sechellia is a species restricted to the Seychelles islands, where it specializes on the fruit Morinda citrifolia (noni). This fruit is known to be toxic to closely related Drosophila species, including D. melanogaster and D. simulans, releasing D. sechellia from interspecific competition when breeding on this substrate. Previously, we showed that larvae of D. sechellia are unable to mount an effective immunological response against wasp attack, while larvae of closely-related species can defend themselves from parasitoid attack by melanotic encapsulation. We hypothesized that this inability constitutes a trait loss due to a reduced risk of parasitoid attack in noni. Here we present a lab experiment and field survey aimed to test the hypothesis that specialization on noni has released D. sechellia from the antagonistic interaction with its larval parasitoids. Our results from the lab experiment suggest that noni may be harmful to parasitoid wasps. Our results from the field survey indicate that D. sechellia was found in ripe noni, whereas another Drosophila species, D. malerkotliana, was present in unripe and overripe stages. Parasitic wasps of the species Leptopilina boulardi emerged from overripe noni, where D. malerkotliana was the most abundant host, but not from ripe noni. These results indicate that the specialization of D. sechellia on noni has indeed drastically altered its ecological interactions, leading to a relaxation in the selection pressure to maintain parasitoid resistance.
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Affiliation(s)
- Laura Salazar-Jaramillo
- Vidarium-Nutrition, Health and Wellness Research Center, Medellin, Colombia.,Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, Netherlands
| | - Bregje Wertheim
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, Netherlands
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18
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Wilsterman K, Ballinger MA, Williams CM. A unifying, eco‐physiological framework for animal dormancy. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13718] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kathryn Wilsterman
- Biological Sciences University of Montana Missoula MT USA
- Integrative Biology University of California Berkeley CA USA
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19
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Moraiti CA, Köppler K, Vogt H, Papadopoulos NT. Effects of photoperiod and relative humidity on diapause termination and post-winter development of Rhagoletis cerasi pupae. BULLETIN OF ENTOMOLOGICAL RESEARCH 2020; 110:588-596. [PMID: 32160932 DOI: 10.1017/s0007485320000073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a univoltine species that undergoes obligatory summer-winter diapause at pupal stage in the soil (2-5 cm) beneath host trees. To study the effects of photoperiod and relative humidity on diapause termination and post-winter developmental duration of R. cerasi, pupae collected from Dossenheim (Germany) were exposed to different photoperiod or relative humidity regimes during a chilling period ranging from 2 to 8.5 months. Specifically, pupae were exposed to four photoperiod regimes: (a) light conditions (24L:00D), (b) dark conditions (00L:24D), (c) short photoperiod (08L:16D) and (d) long photoperiod (16L:08D), as well as to three relative humidity regimes: (a) low (40% RH), (b) medium (60% RH) and (c) high (70-80% RH). Data revealed that relative humidity is not a significant predictor of diapause termination, but it affects the post-winter developmental period. Higher relative humidity promotes post-winter pupae development. On the other hand, photoperiod significantly affected both diapause termination and post-winter development of R. cerasi pupae. Light conditions (24L:00D) accelerate adult emergence, particularly for females. Regardless of the photoperiod (24L:00D, 00L:24D, 08L:16D), rates of adult emergence were high (>75%) for chilling intervals longer than 6.5 months. Nonetheless, exposure to a long day photoperiod (16L:08D), during chilling, dramatically reduced the proportion of adult emergence following 6 months exposure to chilling. Our findings broaden the understanding of factors regulating diapause responses in European cherry fruit fly, local adaptation and synchronization of adult emergence with the ripening period of major hosts.
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Affiliation(s)
- Cleopatra A Moraiti
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Fytokou ST., Volos, 384 46Magnesia, Greece
| | - Kirsten Köppler
- Centre for Agricultural Technology Augustenberg (LTZ), Neßlerstr. 25, 76227Karlsruhe, Germany
| | - Heidrun Vogt
- Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Plant Protection in Fruit Crops and Viticulture, Schwabenheimer Straße 101, 69221Dossenheim, Germany
| | - Nikos T Papadopoulos
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Fytokou ST., Volos, 384 46Magnesia, Greece
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20
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Dowle EJ, Powell THQ, Doellman MM, Meyers PJ, Calvert MB, Walden KKO, Robertson HM, Berlocher SH, Feder JL, Hahn DA, Ragland GJ. Genome-wide variation and transcriptional changes in diverse developmental processes underlie the rapid evolution of seasonal adaptation. Proc Natl Acad Sci U S A 2020; 117:23960-23969. [PMID: 32900926 PMCID: PMC7519392 DOI: 10.1073/pnas.2002357117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Many organisms enter a dormant state in their life cycle to deal with predictable changes in environments over the course of a year. The timing of dormancy is therefore a key seasonal adaptation, and it evolves rapidly with changing environments. We tested the hypothesis that differences in the timing of seasonal activity are driven by differences in the rate of development during diapause in Rhagoletis pomonella, a fly specialized to feed on fruits of seasonally limited host plants. Transcriptomes from the central nervous system across a time series during diapause show consistent and progressive changes in transcripts participating in diverse developmental processes, despite a lack of gross morphological change. Moreover, population genomic analyses suggested that many genes of small effect enriched in developmental functional categories underlie variation in dormancy timing and overlap with gene sets associated with development rate in Drosophila melanogaster Our transcriptional data also suggested that a recent evolutionary shift from a seasonally late to a seasonally early host plant drove more rapid development during diapause in the early fly population. Moreover, genetic variants that diverged during the evolutionary shift were also enriched in putative cis regulatory regions of genes differentially expressed during diapause development. Overall, our data suggest polygenic variation in the rate of developmental progression during diapause contributes to the evolution of seasonality in R. pomonella We further discuss patterns that suggest hourglass-like developmental divergence early and late in diapause development and an important role for hub genes in the evolution of transcriptional divergence.
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Affiliation(s)
- Edwina J Dowle
- Department of Integrative Biology, University of Colorado Denver, Denver, CO 80217;
- Department of Anatomy, University of Otago, 9016 Dunedin, New Zealand
| | - Thomas H Q Powell
- Department of Biological Sciences, Binghamton University-State University of New York, Binghamton, NY 13902
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Department of Ecology and Evolution, The University of Chicago, Chicago, IL 60637
| | - Peter J Meyers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
| | - McCall B Calvert
- Department of Integrative Biology, University of Colorado Denver, Denver, CO 80217
| | - Kimberly K O Walden
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Stewart H Berlocher
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Environmental Change Initiative, University of Notre Dame, Notre Dame, IN 46556
| | - Daniel A Hahn
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado Denver, Denver, CO 80217;
- Department of Entomology, Kansas State University, Manhattan, KS 66506
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21
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Powell THQ, Nguyen A, Xia Q, Feder JL, Ragland GJ, Hahn DA. A rapidly evolved shift in life‐history timing during ecological speciation is driven by the transition between developmental phases. J Evol Biol 2020; 33:1371-1386. [DOI: 10.1111/jeb.13676] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 06/08/2020] [Accepted: 06/29/2020] [Indexed: 01/02/2023]
Affiliation(s)
- Thomas H. Q. Powell
- Entomology and Nematology Department University of Florida Gainesville Florida USA
- Department of Biological Sciences Binghamton University (State University of New York) Binghamton New York USA
| | - Andrew Nguyen
- Entomology and Nematology Department University of Florida Gainesville Florida USA
| | - Qinwen Xia
- Entomology and Nematology Department University of Florida Gainesville Florida USA
| | - Jeffrey L. Feder
- Department of Biological Sciences University of Notre DameNotre Dame Indiana USA
| | - Gregory J. Ragland
- Department of Integrative Biology University of Colorado Denver Denver Colorado USA
| | - Daniel A. Hahn
- Entomology and Nematology Department University of Florida Gainesville Florida USA
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22
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Meyers PJ, Doellman MM, Ragland GJ, Hood GR, Egan SP, Powell THQ, Nosil P, Feder JL. Can the genomics of ecological speciation be predicted across the divergence continuum from host races to species? A case study in Rhagoletis. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190534. [PMID: 32654640 DOI: 10.1098/rstb.2019.0534] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Studies assessing the predictability of evolution typically focus on short-term adaptation within populations or the repeatability of change among lineages. A missing consideration in speciation research is to determine whether natural selection predictably transforms standing genetic variation within populations into differences between species. Here, we test whether and how host-related selection on diapause timing associates with genome-wide differentiation during ecological speciation by comparing ancestral hawthorn and newly formed apple-infesting host races of Rhagoletis pomonella to their sibling species Rhagoletis mendax that attacks blueberries. The associations of 57 857 single nucleotide polymorphisms in a diapause genome-wide-association study (GWAS) on the hawthorn race strongly predicted the direction and magnitude of genomic divergence among the three fly populations at a field site in Fennville, MI, USA. The apple race and R. mendax show parallel changes in the frequencies of putative inversions on three chromosomes associated with the earlier fruiting times of apples and blueberries compared to hawthorns. A diapause GWAS on R. mendax revealed compensatory changes throughout the genome accounting for the earlier eclosion of blueberry, but not apple flies. Thus, a degree of predictability, although not complete, exists in the genomics of diapause across the ecological speciation continuum in Rhagoletis. The generality of this result is placed in the context of other similar systems. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.
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Affiliation(s)
- Peter J Meyers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Gregory J Ragland
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.,Environmental Change Initiative, University of Notre Dame, Notre Dame, IN 46556, USA.,Department of Integrative Biology, University of Colorado Denver, Denver, CO 80217, USA
| | - Glen R Hood
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.,Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Scott P Egan
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.,Department of Biosciences, Rice University, Houston, TX 77005, USA.,Advanced Diagnostics and Therapeutics Initiative, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Thomas H Q Powell
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.,Department Biological Sciences, Binghamton University, Binghamton, NY 13902, USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.,Centre d'Ecologie Fonctionnelle and Evolutive, Centre National de la Recherche Scientifique, Montpellier 34293, France
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.,Environmental Change Initiative, University of Notre Dame, Notre Dame, IN 46556, USA.,Advanced Diagnostics and Therapeutics Initiative, University of Notre Dame, Notre Dame, IN 46556, USA
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23
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Lindestad O, Schmalensee L, Lehmann P, Gotthard K. Variation in butterfly diapause duration in relation to voltinism suggests adaptation to autumn warmth, not winter cold. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13525] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Olle Lindestad
- Department of Zoology Stockholm University Stockholm Sweden
| | | | | | - Karl Gotthard
- Department of Zoology Stockholm University Stockholm Sweden
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24
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Gillespie RG, Bennett GM, De Meester L, Feder JL, Fleischer RC, Harmon LJ, Hendry AP, Knope ML, Mallet J, Martin C, Parent CE, Patton AH, Pfennig KS, Rubinoff D, Schluter D, Seehausen O, Shaw KL, Stacy E, Stervander M, Stroud JT, Wagner C, Wogan GOU. Comparing Adaptive Radiations Across Space, Time, and Taxa. J Hered 2020; 111:1-20. [PMID: 31958131 PMCID: PMC7931853 DOI: 10.1093/jhered/esz064] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 10/28/2019] [Indexed: 01/02/2023] Open
Abstract
Adaptive radiation plays a fundamental role in our understanding of the evolutionary process. However, the concept has provoked strong and differing opinions concerning its definition and nature among researchers studying a wide diversity of systems. Here, we take a broad view of what constitutes an adaptive radiation, and seek to find commonalities among disparate examples, ranging from plants to invertebrate and vertebrate animals, and remote islands to lakes and continents, to better understand processes shared across adaptive radiations. We surveyed many groups to evaluate factors considered important in a large variety of species radiations. In each of these studies, ecological opportunity of some form is identified as a prerequisite for adaptive radiation. However, evolvability, which can be enhanced by hybridization between distantly related species, may play a role in seeding entire radiations. Within radiations, the processes that lead to speciation depend largely on (1) whether the primary drivers of ecological shifts are (a) external to the membership of the radiation itself (mostly divergent or disruptive ecological selection) or (b) due to competition within the radiation membership (interactions among members) subsequent to reproductive isolation in similar environments, and (2) the extent and timing of admixture. These differences translate into different patterns of species accumulation and subsequent patterns of diversity across an adaptive radiation. Adaptive radiations occur in an extraordinary diversity of different ways, and continue to provide rich data for a better understanding of the diversification of life.
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Affiliation(s)
- Rosemary G Gillespie
- University of California, Berkeley, Essig Museum of Entomology & Department of Environmental Science, Policy, and Management, Berkeley, CA
| | - Gordon M Bennett
- University of California Merced, Life and Environmental Sciences Unit, Merced, CA
| | - Luc De Meester
- University of Leuven, Laboratory of Aquatic Ecology, Evolution and Conservation, Leuven, Belguim
| | - Jeffrey L Feder
- University of Notre Dame, Dept. of Biological Sciences, Notre Dame, IN
| | - Robert C Fleischer
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC
| | - Luke J Harmon
- University of Idaho, Dept. of Biological Sciences, Moscow, ID
| | | | | | | | - Christopher Martin
- University of California Berkeley, Integrative Biology and Museum of Vertebrate Zoology, Berkeley, CA
| | | | - Austin H Patton
- Washington State University, School of Biological Sciences, Pullman, WA
| | - Karin S Pfennig
- University of North Carolina at Chapel Hill, Department of Biology, Chapel Hill, NC
| | - Daniel Rubinoff
- University of Hawaiʻi at Manoa, Department of Plant and Environmental Protection Sciences, Honolulu, HI
| | | | - Ole Seehausen
- Institute of Ecology & Evolution, University of Bern, Bern, BE, Switzerland
- Center for Ecology, Evolution & Biogeochemistry, Eawag, Kastanienbaum, LU, Switzerland
| | - Kerry L Shaw
- Cornell University, Neurobiology and Behavior, Tower Road,, Ithaca, NY
| | - Elizabeth Stacy
- University of Nevada Las Vegas, School of Life Sciences, Las Vegas, NV
| | - Martin Stervander
- University of Oregon, Institute of Ecology and Evolution, Eugene, OR
| | - James T Stroud
- Washington University in Saint Louis, Biology, Saint Louis, MO
| | | | - Guinevere O U Wogan
- University of California Berkeley, Environmental Science Policy, and Management, Berkeley, CA
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25
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Zhou Z, Dong X, Su Q, Xia Z, Wang Z, Yuan J, Li C. Effects of Pre-Diapause Temperature and Body Weight on the Diapause Intensity of the Overwintering Generation of Bactrocera minax (Diptera: Tephritidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2020; 20:5760783. [PMID: 32104894 PMCID: PMC7044672 DOI: 10.1093/jisesa/ieaa005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Indexed: 06/10/2023]
Abstract
The Chinese citrus fruit fly, Bactrocera minax (Enderlein), is an economically important pest of citrus. The fly has an obligatory pupal diapause in soil from November to March. However, techniques for predicting or determining the emergence of the adult have, thus far, not been well documented. In this study, we investigated the effects of different pre-diapause temperatures (8, 12, 16, and 20°C) and pupal body weight (five groups according to pupal weight: G-58, 55.0-61.0 mg; G-68, 65-71 mg; G-78, 75-81 mg; G-88, 85-91 mg; G-95, 92-98 mg) on pupal period (the indicator of diapause intensity). The pupal period of B. minax larvae pupated at 8°C was 193.41 d, which was significantly shorter than that of larvae incubated at higher temperatures, suggesting that there was a lower diapause intensity for larvae pupated at lower pre-diapause temperatures. There were also significant differences in the pupal periods at different pupal body weights. The pupal period of G-58 was significantly shorter than that of the heavier groups (G-88 and G-95), and the pupal period increased with increasing pupal body weight in the five groups. Moreover, the pupal period of B. minax significantly and positively correlated to pupal body weight. These findings demonstrate that the pre-diapause temperature and pupal body weight are suitable indicators for predicting the pupal period of overwintering individuals, and the results of this study will contribute to the development of new and effective strategies for predicting the occurrence and population dynamics of B. minax adult.
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Affiliation(s)
- Zhixiong Zhou
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Xiaolin Dong
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Qi Su
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Zhenzhou Xia
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Zailing Wang
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Jiangjiang Yuan
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Chuanren Li
- Institute of Entomology, College of Agriculture, Yangtze University, Jingzhou, Hubei, China
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26
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Wong ELY, Nevado B, Osborne OG, Papadopulos AST, Bridle JR, Hiscock SJ, Filatov DA. Strong divergent selection at multiple loci in two closely related species of ragworts adapted to high and low elevations on Mount Etna. Mol Ecol 2019; 29:394-412. [PMID: 31793091 DOI: 10.1111/mec.15319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 11/28/2019] [Accepted: 11/28/2019] [Indexed: 12/20/2022]
Abstract
Recently diverged species present particularly informative systems for studying speciation and maintenance of genetic divergence in the face of gene flow. We investigated speciation in two closely related Senecio species, S. aethnensis and S. chrysanthemifolius, which grow at high and low elevations, respectively, on Mount Etna, Sicily and form a hybrid zone at intermediate elevations. We used a newly generated genome-wide single nucleotide polymorphism (SNP) dataset from 192 individuals collected over 18 localities along an elevational gradient to reconstruct the likely history of speciation, identify highly differentiated SNPs, and estimate the strength of divergent selection. We found that speciation in this system involved heterogeneous and bidirectional gene flow along the genome, and species experienced marked population size changes in the past. Furthermore, we identified highly-differentiated SNPs between the species, some of which are located in genes potentially involved in ecological differences between species (such as photosynthesis and UV response). We analysed the shape of these SNPs' allele frequency clines along the elevational gradient. These clines show significantly variable coincidence and concordance, indicative of the presence of multifarious selective forces. Selection against hybrids is estimated to be very strong (0.16-0.78) and one of the highest reported in literature. The combination of strong cumulative selection across the genome and previously identified intrinsic incompatibilities probably work together to maintain the genetic and phenotypic differentiation between these species - pointing to the importance of considering both intrinsic and extrinsic factors when studying divergence and speciation.
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Affiliation(s)
- Edgar L Y Wong
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Bruno Nevado
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Owen G Osborne
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | | | - Jon R Bridle
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Simon J Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, UK
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27
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Hood GR, Powell THQ, Doellman MM, Sim SB, Glover M, Yee WL, Goughnour RB, Mattsson M, Schwarz D, Feder JL. Rapid and repeatable host plant shifts drive reproductive isolation following a recent human-mediated introduction of the apple maggot fly, Rhagoletis pomonella. Evolution 2019; 74:156-168. [PMID: 31729753 DOI: 10.1111/evo.13882] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/24/2019] [Accepted: 10/27/2019] [Indexed: 01/26/2023]
Abstract
Ecological speciation via host-shifting is often invoked as a mechanism for insect diversification, but the relative importance of this process is poorly understood. The shift of Rhagoletis pomonella in the 1850s from the native downy hawthorn, Crataegus mollis, to introduced apple, Malus pumila, is a classic example of sympatric host race formation, a hypothesized early stage of ecological speciation. The accidental human-mediated introduction of R. pomonella into the Pacific Northwest (PNW) in the late 1970s allows us to investigate how novel ecological opportunities may trigger divergent adaptation and host race formation on a rapid timescale. Since the introduction, the fly has spread in the PNW, where in addition to apple, it now infests native black hawthorn, Crataegus douglasii, and introduced ornamental hawthorn, Crataegus monogyna. We use this "natural experiment" to test for genetic differentiation among apple, black, and ornamental hawthorn flies co-occurring at three sympatric sites. We report evidence that populations of all three host-associations are genetically differentiated at the local level, indicating that partial reproductive isolation has evolved in this novel habitat. Our results suggest that conditions suitable for initiating host-associated divergence may be common in nature, allowing for the rapid evolution of new host races when ecological opportunity arises.
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Affiliation(s)
- Glen R Hood
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, 48202
| | - Thomas H Q Powell
- Department of Biological Sciences, Binghamton University, Binghamton, New York, 13902
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556
| | - Sheina B Sim
- USDA-ARS Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center, Hilo, Hawaii, 96720
| | - Mary Glover
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556
| | - Wee L Yee
- USDA-ARS Yakima Agricultural Research Laboratory, Wapato, Washington, 98951
| | | | - Monte Mattsson
- Environmental Services, City of Portland, Portland, Oregon, 97204
| | - Dietmar Schwarz
- Department of Biology, Western Washington University, Bellingham, Washington, 98225
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556.,Advanced Diagnostics and Therapeutics, University of Notre Dame, Notre Dame, Indiana, 46556.,Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana, 46556
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28
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Dong YC, Chen ZZ, Clarke AR, Niu CY. Changes in Energy Metabolism Trigger Pupal Diapause Transition of Bactrocera minax After 20-Hydroxyecdysone Application. Front Physiol 2019; 10:1288. [PMID: 31736767 PMCID: PMC6831740 DOI: 10.3389/fphys.2019.01288] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/25/2019] [Indexed: 11/21/2022] Open
Abstract
Correct timing of diapause entry and exit is critical for a species' survival. While many aspects of insect diapause are well-studied, the mechanisms underlying diapause termination remain largely unknown. The Chinese citrus fly, Bactrocera minax, is a univoltine insect with an obligatory pupal diapause. The application of 20-hydroxyecdysone (20E) is known to terminate diapause in B. minax, and we used this approach, along with isobaric tags for relative and absolute quantitation technology, to determine the proteins associated with diapause termination in this fly. Among 2,258 identified proteins, 1,169 proteins significantly differed at 1, 2, and 5 days post-injection of 20E, compared with the solvent-injected control group. Functional annotation revealed that the majority of differentially expressed proteins were enriched in the core energy metabolism of amino acids, proteins, lipids, and carbohydrates as well as in signal transduction pathways including PPAR signaling, Calcium signaling, Glucagon signaling, VEGF signaling, Ras signaling, cGMP-PKG signaling, and cAMP signaling. A combined transcriptomic and proteomic analysis suggested the involvement of energy metabolism in the response of diapause transition. RNA interference experiments disclosed that a 20E injection triggers diapause termination probably through non-genomic actions, rather than nuclear receptor mediated genomic actions. Our results provide extensive proteomic resources for insect diapause transition and offer a potential for pest control by incapacitating the regulation of diapause termination either by breaking diapause prematurely or by delaying diapause termination to render diapausing individuals at a high risk of mortality.
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Affiliation(s)
- Yong-Cheng Dong
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China.,Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhen-Zhong Chen
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Anthony R Clarke
- Faculty of Science and Technology, School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Chang-Ying Niu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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29
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Bakovic V, Schuler H, Schebeck M, Feder JL, Stauffer C, Ragland GJ. Host plant-related genomic differentiation in the European cherry fruit fly, Rhagoletis cerasi. Mol Ecol 2019; 28:4648-4666. [PMID: 31495015 PMCID: PMC6899720 DOI: 10.1111/mec.15239] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 12/13/2022]
Abstract
Elucidating the mechanisms and conditions facilitating the formation of biodiversity are central topics in evolutionary biology. A growing number of studies imply that divergent ecological selection may often play a critical role in speciation by counteracting the homogenising effects of gene flow. Several examples involve phytophagous insects, where divergent selection pressures associated with host plant shifts may generate reproductive isolation, promoting speciation. Here, we use ddRADseq to assess the population structure and to test for host‐related genomic differentiation in the European cherry fruit fly, Rhagoletis cerasi (L., 1758) (Diptera: Tephritidae). This tephritid is distributed throughout Europe and western Asia, and has adapted to two different genera of host plants, Prunus spp. (cherries) and Lonicera spp. (honeysuckle). Our data imply that geographic distance and geomorphic barriers serve as the primary factors shaping genetic population structure across the species range. Locally, however, flies genetically cluster according to host plant, with consistent allele frequency differences displayed by a subset of loci between Prunus and Lonicera flies across four sites surveyed in Germany and Norway. These 17 loci display significantly higher FST values between host plants than others. They also showed high levels of linkage disequilibrium within and between Prunus and Lonicera flies, supporting host‐related selection and reduced gene flow. Our findings support the existence of sympatric host races in R. cerasi embedded within broader patterns of geographic variation in the fly, similar to the related apple maggot, Rhagoletis pomonella, in North America.
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Affiliation(s)
- Vid Bakovic
- Department of Forest and Soil Sciences, BOKU, University of Natural Resources and Life Sciences Vienna, Vienna, Austria.,Department of Biology, IFM, University of Linköping, Linköping, Sweden
| | - Hannes Schuler
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy
| | - Martin Schebeck
- Department of Forest and Soil Sciences, BOKU, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Christian Stauffer
- Department of Forest and Soil Sciences, BOKU, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado-Denver, Denver, CO, USA
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30
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Rull J, Lasa R, Aluja M. Differential Response to Photoperiod by Diverging Rhagoletis pomonella (Diptera: Tephritidae) Populations Exploiting Host Plants with Different Fruiting Phenology. NEOTROPICAL ENTOMOLOGY 2019; 48:757-763. [PMID: 31129778 DOI: 10.1007/s13744-019-00693-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/25/2019] [Indexed: 06/09/2023]
Abstract
Photoperiod has been found to influence the proportion of non-dormant individuals and the duration of dormancy among North American populations of Rhagoletis pomonella (Walsh) (Diptera: Tephritidae). In particular, long days combined with high temperatures can produce a 100% non-dormant generation. There are several genetically distinct populations of R. pomonella in the highlands of Mexico, two of which occur at the same latitude, at different elevations, that exploit hawthorn plants with different fruiting phenology (early (summer-fall) and late (winter)). Flies exploiting such hosts might use day length in different ways as a cue to match adult emergence with fruit availability. Here, we compared responses of pupae from two Mexican populations of R. pomonella to a 12/12 L/D photoperiod, a long-day photoperiod 17/7 L/D, and continuous illumination. Experiments were performed under warm conditions (27°C). Day length had no effect on the proportion of adults emerged from the early-fruiting hawthorn population, while pupae extracted from late-fruiting hawthorns and exposed to long days emerged as adults in lower proportions and engaged in prolonged dormancy in greater proportions than those exposed to a short day. Photoperiod had no effect on the proportion from both Mexican populations foregoing dormancy. Dormancy duration was affected by photoperiod and was longer than previous reports for North American populations. Host plant fruiting phenology may be the driver of these differences. These findings, coupled with previous reports of genetic and biological differences, suggest that the Eje Volcanico Trans-Mexicano R. pomonella population may actually be a distinct species.
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Affiliation(s)
- J Rull
- LIEMEN-División Control Biológico de Plagas, PROIMI Biotecnología-CONICET, San Miguel de Tucumán, Tucumán, Argentina.
| | - R Lasa
- Instituto de Ecología, Xalapa, Veracruz, Mexico
| | - M Aluja
- Instituto de Ecología, Xalapa, Veracruz, Mexico
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31
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Jing TX, Zhang YX, Dou W, Jiang XY, Wang JJ. First Insights into the Intrapuparial Development of Bactrocera dorsalis (Hendel): Application in Predicting Emergence Time for Tephritid Fly Control. INSECTS 2019; 10:insects10090283. [PMID: 31484469 PMCID: PMC6780237 DOI: 10.3390/insects10090283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/29/2019] [Accepted: 09/02/2019] [Indexed: 12/20/2022]
Abstract
Intrapuparial development is a special pattern of metamorphosis in cyclorrhaphous flies, in which the pupa forms in an opaque, barrel-like puparium. This has been well studied in forensic insects for age estimations. In this study, the intrapuparial development of a quarantine agricultural pest, Bactrocera dorsalis (Hendel), was studied under a constant temperature of 27 ± 1 °C and 70 ± 5% relative humidity. Results showed that intrapuparial development could be divided into five stages: Larval-pupal apolysis, cryptocephalic pupa, phanerocephalic pupa, pharate adult, and emergent adult. It lays a morphology-based foundation for molecular mechanism studies and enhances the understanding of the physiological basis for changes in intrapuparial development. More importantly, the chronology of intrapuparial development can be used to predict the emergence time of tephritid flies, indicating when to spray insecticides to control these phytophagous agricultural pests. This may be an effective approach to reduce the use of insecticides and slow down the evolution of insecticidal resistance.
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Affiliation(s)
- Tian-Xing Jing
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Ying-Xin Zhang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Wei Dou
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Xin-Yi Jiang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China.
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China.
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32
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Rull J, Lasa R, Guillén L, Aluja M. The Effect of Winter Length on Duration of Dormancy and Survival of Rhagoletis completa (Diptera: Tephritidae) and Associated Parasitoids From Northeastern Mexico. JOURNAL OF INSECT SCIENCE (ONLINE) 2019; 19:5490192. [PMID: 31095311 PMCID: PMC6521683 DOI: 10.1093/jisesa/iez034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Indexed: 06/09/2023]
Abstract
The walnut husk fly Rhagoletis completa (Cresson), native to the Midwestern United States and Mexico, is invasive in California and Europe. It is one of the most important pests of walnuts in areas gathering 30% of the world production. Knowledge of life-history regulation is important for the design of management strategies. Research on dormancy has been performed on invasive populations, and not on populations at the southern extreme of its native range. Here, we examined the effect of winter length on fly and parasitoid emergence, survival, and duration of dormancy. Percent emergence was higher for chill periods at 5°C ranging from 8 to 20 wk. No or insufficient chill resulted in low emergence and a significant proportion of individuals in prolonged dormancy (>1 yr). Duration of dormancy was longer for pupae at constant temperatures and a 4-wk chill period than longer winter durations. Dormancy was longer for Mexican than that reported for U.S. populations, suggesting the existence of a latitudinal cline where populations at southern latitudes have evolved slower metabolic rates. Three parasitoid species were found associated with R. completa (Aganaspis alujai (Wharton and Ovruski) (Hymenoptera: Figitidae), Diachasmimorpha juglandis Muesebeck, and Diachasmimorpha mellea Gahan) (Hymenoptera: Braconidae). Results suggest that rearing of R. completa is possible by subjecting pupae to chill periods between 8 and 20 wk. Overwintering mortality of flies and A. alujai could be further reduced above 5°C. Our findings can contribute for the accurate development of predictive models on invasion potential, development, fly and parasitoid rearing, and biological control.
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Affiliation(s)
- Juan Rull
- PROIMI Biotecnología-CONICET, LIEMEN-División Control Biológico de Plagas, Av. Belgrano y Pje. Caseros, T4001MVB San Miguel de Tucumán, Tucumán, Argentina
| | - Rodrigo Lasa
- Instituto de Ecología, A.C., Carretera Antigua a Coatepec no. 351, Colonia el Haya, CP 91070 Xalapa, Veracruz, México
| | - Larissa Guillén
- Instituto de Ecología, A.C., Carretera Antigua a Coatepec no. 351, Colonia el Haya, CP 91070 Xalapa, Veracruz, México
| | - Martin Aluja
- Instituto de Ecología, A.C., Carretera Antigua a Coatepec no. 351, Colonia el Haya, CP 91070 Xalapa, Veracruz, México
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33
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Nash W, Mohorianu I, Chapman T. Mate choice and gene expression signatures associated with nutritional adaptation in the medfly (Ceratitis capitata). Sci Rep 2019; 9:6704. [PMID: 31040302 PMCID: PMC6491435 DOI: 10.1038/s41598-019-42610-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/25/2019] [Indexed: 11/09/2022] Open
Abstract
Evolutionary responses to nutrition are key to understanding host shifts and the resulting potential for reproductive isolation. Experimental evolution has previously been used to describe the responses of the medfly (Ceratitis capitata) to larval diets with different nutritional properties. Within 30 generations this led to divergence in larval development time, egg to adult survival and adaptation in adult body size. Here we used mRNA-seq to identify differences in gene expression patterns in these same populations, using males from the 60th generation of nutritional selection. We validated differential expression by using qRT-PCR and found that genes linked to metabolism, oxidative phosphorylation and proteolysis were significantly over-represented among the differentially expressed genes. The results provide the first genome-wide survey of the putative mechanisms underpinning evolved responses to nutritional adaptation. In addition, we tested the hypothesis that nutritional adaptation can alter mating patterns. We found evidence for assortative mating by diet at generation 60, but not 90. Hence, the pattern was variable across generations and there was no evidence overall for any isolating mating divergence between the lines. Overall, the results provide insight into the mechanisms underpinning dietary adaptation and extend our knowledge of which traits represent core responses to nutritional selection.
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Affiliation(s)
- Will Nash
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Earlham Institute, Norwich Research Park, Norwich, NR4 7UZ, UK
| | - Irina Mohorianu
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK. .,School of Computing Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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34
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Bonner C, Sokolov NA, Westover SE, Ho M, Weis AE. Estimating the impact of divergent mating phenology between residents and migrants on the potential for gene flow. Ecol Evol 2019; 9:3770-3783. [PMID: 31015965 PMCID: PMC6468075 DOI: 10.1002/ece3.5001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/24/2019] [Accepted: 01/24/2019] [Indexed: 11/15/2022] Open
Abstract
Gene flow between populations can allow the spread of beneficial alleles and genetic diversity between populations, with importance to conservation, invasion biology, and agriculture. Levels of gene flow between populations vary not only with distance, but also with divergence in reproductive phenology. Since phenology is often locally adapted, arriving migrants may be reproductively out of synch with residents, which can depress realized gene flow. In flowering plants, the potential impact of phenological divergence on hybridization between populations can be predicted from overlap in flowering schedules-the daily count of flowers capable of pollen exchange-between a resident and migrant population. The accuracy of this prospective hybridization estimate, based on parental phenotypes, rests upon the assumptions of unbiased pollen transfer between resident and migrant active flowers. We tested the impact of phenological divergence on resident-migrant mating frequencies in experiments that mimicked a single large gene flow event. We first prospectively estimated mating frequencies two lines of Brassica rapaselected or early and late flowering. We then estimated realized mating frequencies retrospectively through progeny testing. The two estimates strongly agreed in a greenhouse experiment, where procedures ensured saturating, unbiased pollination. Under natural pollination in the field, the rate of resident-migrant mating, was lower than estimated by phenological divergence alone, although prospective and retrospective estimates were correlated. In both experiments, differences between residents and migrants in flowering schedule shape led to asymmetric hybridization. Results suggest that a prospective estimate of hybridization based on mating schedules can be a useful, although imperfect, tool for evaluating potential gene flow. They also illustrate the impact of mating phenology on the magnitude and symmetry of reproductive isolation.
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Affiliation(s)
- Colin Bonner
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Nina A. Sokolov
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Sally Erin Westover
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Michelle Ho
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Arthur E. Weis
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
- Koffler Scientific Reserve at Jokers HillUniversity of TorontoTorontoONCanada
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35
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Emery SE, Mills NJ. Sources of Variation in the Adult Flight of Walnut Husk Fly (Diptera: Tephritidae): A Phenology Model for California Walnut Orchards. ENVIRONMENTAL ENTOMOLOGY 2019; 48:234-244. [PMID: 30520946 DOI: 10.1093/ee/nvy170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 06/09/2023]
Abstract
A phenology model of the walnut husk fly, Rhagoletis completa Cresson, was developed to more accurately predict the timing of the flight period and optimize management decisions. A data set of 153 orchard years in which adults were trapped throughout the season was used for the development and validation of this model. Data from California Irrigation Management Information System (CIMIS) weather stations were used to match orchard-year datasets with historical climatic data on degree-day (DD) accumulation, winter chill, and winter rainfall. A cumulative Weibull distribution was used to model the relationship between cumulative trap catch and DD accumulation for R. completa in California. The model was used to predict thermal requirements for the start (5% cumulative trap catch) and mid-point (50% cumulative trap catch) of the flight period, which were 1,670 and 2,179 DDs, respectively. The prediction for 50% cumulative trap catch of R. completa in California was much higher than the thermal requirement estimated in Oregon previously (1,751 DDs). Linear mixed effects models were used to evaluate other environmental and orchard-specific factors which could explain the large variation between predicted and observed thermal requirements for both the start and mid-point of the flight period. Latitude, walnut cultivar leaf-out time, orchard age and year, as a continuous variable, all contributed significantly to explain deviations from the predictions of the DD model for individual orchard years. Such factors can be used both to adjust predicted thermal requirements for these two specific and informative stages of the flight period, and to provide a basis for ecological and evolutionary hypotheses.
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Affiliation(s)
| | - Nicholas J Mills
- Department of Environmental Science, Policy and Management, University of California Berkeley, 130 Mulford Hall, Berkeley, CA 94720-3114
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Chick LD, Strickler SA, Perez A, Martin RA, Diamond SE. Urban heat islands advance the timing of reproduction in a social insect. J Therm Biol 2019; 80:119-125. [PMID: 30784475 DOI: 10.1016/j.jtherbio.2019.01.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/26/2018] [Accepted: 01/06/2019] [Indexed: 10/27/2022]
Abstract
For many species, the timing of life cycle events is advancing under contemporary global climate change. However, much less is known regarding phenological shifts as a result of other sources of anthropogenic change, such as urban warming. In both cases, progress has been hampered by a focus on phenological traits such as the timing of emergence, rather than the phenology of more directly related fitness traits such as the timing of reproduction. Here we explore how urban heat island effects shape the timing of reproduction in an acorn-dwelling ant. We used a common garden experiment with acorn ants collected from three cities in the eastern United States along a latitudinal gradient and reared long-term in the laboratory under five temperature treatments. This allowed us to quantify the effects of temperature on reproductive phenology across three scales-a biogeographic temperature cline, three urban vs. rural temperature comparisons, and five laboratory rearing temperatures. At our northernmost and southernmost cities (spanning 6° of latitude), we found both urbanization and warmer laboratory rearing temperature significantly advanced reproductive phenology; ants from the lowest latitude city also had earlier reproductive phenology compared with the higher latitude cities. In the field, the differences in urban versus rural acorn ant reproductive phenology translate to approximately one month earlier reproduction in the urban populations. For insects with synchronous mating events, such as ants, shifts in the already short window of time to reproduce could limit mating across environments, potentially leading to reproductive isolation between urban and rural populations.
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Affiliation(s)
- Lacy D Chick
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA.
| | | | - Abe Perez
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ryan A Martin
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Sarah E Diamond
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
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Doellman MM, Egan SP, Ragland GJ, Meyers PJ, Hood GR, Powell THQ, Lazorchak P, Hahn DA, Berlocher SH, Nosil P, Feder JL. Standing geographic variation in eclosion time and the genomics of host race formation in Rhagoletis pomonella fruit flies. Ecol Evol 2019; 9:393-409. [PMID: 30680122 PMCID: PMC6342182 DOI: 10.1002/ece3.4758] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/30/2018] [Accepted: 11/01/2018] [Indexed: 12/12/2022] Open
Abstract
Taxa harboring high levels of standing variation may be more likely to adapt to rapid environmental shifts and experience ecological speciation. Here, we characterize geographic and host-related differentiation for 10,241 single nucleotide polymorphisms in Rhagoletis pomonella fruit flies to infer whether standing genetic variation in adult eclosion time in the ancestral hawthorn (Crataegus spp.)-infesting host race, as opposed to new mutations, contributed substantially to its recent shift to earlier fruiting apple (Malus domestica). Allele frequency differences associated with early vs. late eclosion time within each host race were significantly related to geographic genetic variation and host race differentiation across four sites, arrayed from north to south along a 430-km transect, where the host races co-occur in sympatry in the Midwest United States. Host fruiting phenology is clinal, with both apple and hawthorn trees fruiting earlier in the North and later in the South. Thus, we expected alleles associated with earlier eclosion to be at higher frequencies in northern populations. This pattern was observed in the hawthorn race across all four populations; however, allele frequency patterns in the apple race were more complex. Despite the generally earlier eclosion timing of apple flies and corresponding apple fruiting phenology, alleles on chromosomes 2 and 3 associated with earlier emergence were paradoxically at lower frequency in the apple than hawthorn host race across all four sympatric sites. However, loci on chromosome 1 did show higher frequencies of early eclosion-associated alleles in the apple than hawthorn host race at the two southern sites, potentially accounting for their earlier eclosion phenotype. Thus, although extensive clinal genetic variation in the ancestral hawthorn race exists and contributed to the host shift to apple, further study is needed to resolve details of how this standing variation was selected to generate earlier eclosing apple fly populations in the North.
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Affiliation(s)
| | - Scott P. Egan
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
- Advanced Diagnostics and Therapeutics InitiativeUniversity of Notre DameNotre DameIndiana
- Department of BiosciencesRice UniversityHoustonTexas
| | - Gregory J. Ragland
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
- Environmental Change InitiativeUniversity of Notre DameNotre DameIndiana
- Department of Integrative BiologyUniversity of Colorado–DenverDenverColorado
| | - Peter J. Meyers
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
| | - Glen R. Hood
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
- Department of Biological SciencesWayne State UniversityDetroitMichigan
| | - Thomas H. Q. Powell
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
- Department of Biological SciencesState University of New York–BinghamtonBinghamtonNew York
| | - Peter Lazorchak
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
- Department of Computer ScienceJohns Hopkins UniversityBaltimoreMaryland
| | - Daniel A. Hahn
- Department of Entomology and NematologyUniversity of FloridaGainesvilleFlorida
| | - Stewart H. Berlocher
- Department of EntomologyUniversity of Illinois at Urbana‐ChampaignUrbanaIllinois
| | - Patrik Nosil
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Jeffrey L. Feder
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
- Advanced Diagnostics and Therapeutics InitiativeUniversity of Notre DameNotre DameIndiana
- Environmental Change InitiativeUniversity of Notre DameNotre DameIndiana
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Zhou Y, Sun D, Quan WL, Ding N, Liu W, Ma WH, Wang XP. Divergence in larval diapause induction between the rice and water-oat populations of the striped stem borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:29715-29724. [PMID: 30145755 DOI: 10.1007/s11356-018-2930-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Differences in diapause traits can result in the seasonal reproductive isolation of host plant-associated insect populations and thereby facilitate the population divergence. The striped stem borer, Chilo suppressalis, has two host plant-associated populations: rice population and water-oat population. Several studies have found evidence that seasonal reproductive isolation between these populations is at least partially due to interpopulation differences in diapause. However, there still lack unambiguous evidence comparing characteristics of diapause induction for both populations. We compared the photoperiodic response and the age of peak photoperiod sensitivity of these populations and used RNA-Seq to compare the molecular response of diapause induction between populations. The photoperiodic response of the two populations differed at 25 °C; the critical night length of larvae from the rice population was 11 h and 20 min, whereas no obvious critical night length was in those from the water-oat population. In rice population, larvae were most sensitive to photoperiod at 9-12 days of age, whereas in water-oat population, larvae were the most sensitive to photoperiod at 9-10 days of age. The RNA-Seq results indicated that there were several differences in the molecular response of diapause induction and small overlap in differentially expressed genes (DEGs) between populations. Furthermore, GO analysis indicated that both rice and water-oat population's DEGs were significantly enriched in heme and iron binding. Besides, water-oat population's DEGs were significantly enriched in metabolizing nutrients but rice population's DEGs do not. Thus, our results described differences in diapause induction between rice and water-oat populations of C. suppressalis which could affect the timing of diapause and thereby contribute to the seasonal reproductive isolation of these host plant-associated populations. In conclusion, this work suggests that difference in diapause induction could promote the population divergence in insects associated with different host plants.
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Affiliation(s)
- Yuan Zhou
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Dan Sun
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Wei-Li Quan
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Nan Ding
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Wen Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
| | - Wei-Hua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Xiao-Ping Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
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Rull J, Tadeo E, Lasa R, Aluja M. The effect of winter length on duration of dormancy and survival of specialized herbivorous Rhagoletis fruit flies from high elevation environments with acyclic climatic variability. BULLETIN OF ENTOMOLOGICAL RESEARCH 2018; 108:461-470. [PMID: 28925346 DOI: 10.1017/s0007485317000979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Dormancy can be defined as a state of suppressed development allowing insects to cope with adverse conditions and plant phenology. Among specialized herbivorous insects exploiting seasonal resources, diapause frequently evolves as a strategy to adjust to predictable plant seasonal cycles. To cope with acyclic and unpredictable climatic events, it has been found for some insects that a proportion of the population undergoes prolonged dormancy. We compared the response of three species in the Rhagoletis cingulata species group exploiting plants differing in fruiting phenology from environments varying in frequency and timing of acyclic climatic catastrophic events (frost during flowering and fruit set) and varying also in the time of the onset of the rainy season. Small proportions (10 months), and large proportions of pupae died without emerging as adults. The number of days elapsed from the end of artificial winter and adult eclosion was longer for R. cingulata exploiting late fruiting Prunus serotina in Northeastern Mexico than for flies recovered from earlier fruiting plants in the central Altiplano. Rhagoletis turpiniae and northeastern R. cingulata pupae suffered high proportions of parasitism. Large proportions of R. cingulata from central Mexico engaging in prolonged dormancy may be explained by the fact that flowering and fruit set for its host, P. serotina var capuli, driven by the timing of maximum precipitation, matches a period of highest probability of frost often resulting in large areas with fruitless trees at unpredictable time intervals. As a consequence of differences in host plant fruiting phenology, central and northeastern Mexican R. cingulata were found to be allochronically isolated. Prolonged dormancy may have resulted in escape from parasitism.
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Affiliation(s)
- J Rull
- PROIMI Biotecnología-CONICET,LIEMEN-División Control Biológico de Plagas,Av. Belgrano y Pje. Caseros,T4001MVB San Miguel de Tucumán,Tucumán,Argentina
| | - E Tadeo
- Red de Manejo Biorracional de Plagas y Vectores,Instituto de Ecología,A.C.,Xalapa,Veracruz 91070,México
| | - R Lasa
- Red de Manejo Biorracional de Plagas y Vectores,Instituto de Ecología,A.C.,Xalapa,Veracruz 91070,México
| | - M Aluja
- Red de Manejo Biorracional de Plagas y Vectores,Instituto de Ecología,A.C.,Xalapa,Veracruz 91070,México
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Identification of a New Blend of Host Fruit Volatiles from Red Downy Hawthorn, Crataegus mollis, Attractive to Rhagoletis pomonella Flies from the Northeastern United States. J Chem Ecol 2018; 44:671-680. [PMID: 29923080 DOI: 10.1007/s10886-018-0977-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/16/2018] [Accepted: 06/12/2018] [Indexed: 10/28/2022]
Abstract
A new blend of volatiles was identified for the fruit of downy red hawthorn, Crataegus mollis, that is attractive to Rhagoletis pomonella flies infesting this host in the northeastern USA. The new blend was as attractive as the previously identified mixture but is more complex in the number of odorants (six in the old versus ten in the new) and differs significantly in the ratio of three volatiles, 3-methylbutan-1-ol, butyl hexanoate, and dihydro-β-ionone, that are common to both blends and exerted agonist or antagonist effects on behavior in a flight tunnel assay. However, behavioral results with the old and new northern hawthorn blends, as well as modified blends with substituted ratios of 3-methylbutan-1-ol, butyl hexanoate, dihydro-β-ionone, indicated that the 'agonist' or 'antagonist' effects of these volatiles depended on the ratio, or balance of compounds within the blend. In addition, the new blend contains a number of esters identified from the headspace of domesticated apple, Malus domestica, that are attractive to apple-origin R. pomonella, and present in the five other blends from southern hawthorns, including the southern C. mollis var. texana blend, but are not part of the previously identified blend from northern C. mollis fruit. This finding supports the hypothesis that in addition to providing specificity to the odor blends of the northern and southern hawthorn populations, the presence of the significant amounts of ester compounds in the new northern hawthorn blend might have provided a source of standing variation that could help explain the shift in host preference by C. mollis-infesting flies to introduced apple in the mid-1800's.
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Genomic Differentiation during Speciation-with-Gene-Flow: Comparing Geographic and Host-Related Variation in Divergent Life History Adaptation in Rhagoletis pomonella. Genes (Basel) 2018; 9:genes9050262. [PMID: 29783692 PMCID: PMC5977202 DOI: 10.3390/genes9050262] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 05/09/2018] [Accepted: 05/09/2018] [Indexed: 12/16/2022] Open
Abstract
A major goal of evolutionary biology is to understand how variation within populations gets partitioned into differences between reproductively isolated species. Here, we examine the degree to which diapause life history timing, a critical adaptation promoting population divergence, explains geographic and host-related genetic variation in ancestral hawthorn and recently derived apple-infesting races of Rhagoletis pomonella. Our strategy involved combining experiments on two different aspects of diapause (initial diapause intensity and adult eclosion time) with a geographic survey of genomic variation across four sites where apple and hawthorn flies co-occur from north to south in the Midwestern USA. The results demonstrated that the majority of the genome showing significant geographic and host-related variation can be accounted for by initial diapause intensity and eclosion time. Local genomic differences between sympatric apple and hawthorn flies were subsumed within broader geographic clines; allele frequency differences within the races across the Midwest were two to three-fold greater than those between the races in sympatry. As a result, sympatric apple and hawthorn populations displayed more limited genomic clustering compared to geographic populations within the races. The findings suggest that with reduced gene flow and increased selection on diapause equivalent to that seen between geographic sites, the host races may be recognized as different genotypic entities in sympatry, and perhaps species, a hypothesis requiring future genomic analysis of related sibling species to R. pomonella to test. Our findings concerning the way selection and geography interplay could be of broad significance for many cases of earlier stages of divergence-with-gene flow, including (1) where only modest increases in geographic isolation and the strength of selection may greatly impact genetic coupling and (2) the dynamics of how spatial and temporal standing variation is extracted by selection to generate differences between new and discrete units of biodiversity.
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42
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Kopp M, Servedio MR, Mendelson TC, Safran RJ, Rodríguez RL, Hauber ME, Scordato EC, Symes LB, Balakrishnan CN, Zonana DM, van Doorn GS. Mechanisms of Assortative Mating in Speciation with Gene Flow: Connecting Theory and Empirical Research. Am Nat 2018; 191:1-20. [DOI: 10.1086/694889] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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43
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Ragland GJ, Doellman MM, Meyers PJ, Hood GR, Egan SP, Powell THQ, Hahn DA, Nosil P, Feder JL. A test of genomic modularity among life-history adaptations promoting speciation with gene flow. Mol Ecol 2017; 26:3926-3942. [DOI: 10.1111/mec.14178] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/12/2017] [Accepted: 04/14/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Gregory J. Ragland
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Environmental Change Initiative; University of Notre Dame; Notre Dame IN USA
- Department of Integrative Biology; University of Colorado - Denver; Denver CO USA
| | | | - Peter J. Meyers
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
| | - Glen R. Hood
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Department of Biosciences; Rice University; Houston TX USA
| | - Scott P. Egan
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Department of Biosciences; Rice University; Houston TX USA
- Advanced Diagnostics and Therapeutics Initiative; University of Notre Dame; Notre Dame IN USA
| | - Thomas H. Q. Powell
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Department of Entomology and Nematology; University of Florida; Gainesville FL USA
- Department of Biological Sciences; State University of New York - Binghamton; Binghamton NY USA
| | - Daniel A. Hahn
- Department of Entomology and Nematology; University of Florida; Gainesville FL USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
| | - Jeffrey L. Feder
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Environmental Change Initiative; University of Notre Dame; Notre Dame IN USA
- Advanced Diagnostics and Therapeutics Initiative; University of Notre Dame; Notre Dame IN USA
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Wadgymar SM, Weis AE. Phenological mismatch and the effectiveness of assisted gene flow. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:547-558. [PMID: 27943504 DOI: 10.1111/cobi.12877] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 09/18/2016] [Accepted: 09/21/2016] [Indexed: 06/06/2023]
Abstract
The persistence of narrowly adapted species under climate change will depend on their ability to migrate apace with their historical climatic envelope or to adapt in place to maintain fitness. This second path to persistence can only occur if there is sufficient genetic variance for response to new selection regimes. Inadequate levels of genetic variation can be remedied through assisted gene flow (AGF), that is the intentional introduction of individuals genetically adapted to localities with historic climates similar to the current or future climate experienced by the resident population. However, the timing of reproduction is frequently adapted to local conditions. Phenological mismatch between residents and migrants can reduce resident × migrant mating frequencies, slowing the introgression of migrant alleles into the resident genetic background and impeding evolutionary rescue efforts. Focusing on plants, we devised a method to estimate the frequency of resident × migrant matings based on flowering schedules and applied it in an experiment that mimicked the first generation of an AGF program with Chamaecrista fasciculata, a prairie annual, under current and expected future temperature regimes. Phenological mismatch reduced the potential for resident × migrant matings by 40-90%, regardless of thermal treatment. The most successful migrant sires were the most resident like in their flowering time, further biasing the genetic admixture between resident and migrant populations. Other loci contributing to local adaptation-heat-tolerance genes, for instance-may be in linkage disequilibrium with phenology when residents and migrants are combined into a single mating pool. Thus, introgression of potentially adaptive migrant alleles into the resident genetic background is slowed when selection acts against migrant phenology. Successful AGF programs may require sustained high immigration rates or preliminary breeding programs when phenologically matched migrant source populations are unavailable.
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Affiliation(s)
- Susana M Wadgymar
- Department of Genetics, University of Georgia, 120 Green Street, Athens, GA, 30602-7223, U.S.A
| | - Arthur E Weis
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
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45
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Taylor RS, Friesen VL. The role of allochrony in speciation. Mol Ecol 2017; 26:3330-3342. [DOI: 10.1111/mec.14126] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/17/2017] [Accepted: 03/20/2017] [Indexed: 12/15/2022]
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46
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Vertacnik KL, Linnen CR. Evolutionary genetics of host shifts in herbivorous insects: insights from the age of genomics. Ann N Y Acad Sci 2017; 1389:186-212. [DOI: 10.1111/nyas.13311] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/16/2016] [Accepted: 12/22/2016] [Indexed: 12/25/2022]
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47
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Cha DH, Olsson SB, Yee WL, Goughnour RB, Hood GR, Mattsson M, Schwarz D, Feder JL, Linn CE. Identification of Host Fruit Volatiles from Snowberry (Symphoricarpos albus), Attractive to Rhagoletis zephyria Flies from the Western United States. J Chem Ecol 2017; 43:188-197. [PMID: 28078623 DOI: 10.1007/s10886-016-0814-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 12/13/2016] [Accepted: 12/21/2016] [Indexed: 11/27/2022]
Abstract
A mixture of behaviorally active volatiles was identified from the fruit of snowberry, Symphoricarpos albus laevigatus, for Rhagoletis zephyria flies reared from snowberry fruit. A nine-component blend containing 3-methylbutan-1-ol (3%), dimethyl trisulfide (1%), 1-octen-3-ol (40%), myrcene (8%), nonanal (9%), linalool (13%), (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT, 6%), decanal (15%), and β-caryophyllene (5%) was identified that gave consistent electroantennogram activity and was behaviorally active in flight tunnel tests. In other flight tunnel assays, snowberry flies from two sites in Washington state, USA, displayed significantly greater levels of upwind oriented flight to sources with the snowberry volatile blend compared with previously identified volatile blends from domestic apple (Malus domestica) and downy hawthorn (Crataegus mollis) fruit from the eastern USA, and domestic apple, black hawthorn (C. douglasii) and ornamental hawthorn (C. monogyna) from Washington state. Selected subtraction assays showed that whereas removal of DMNT or 1-octen-3-ol significantly reduced the level of upwind flight, removal of myrcene and β-caryophyllene, or dimethyl trisulfide alone did not significantly affect the proportion of upwind flights. Our findings add to previous studies showing that populations of Rhagoletis flies infesting different host fruit are attracted to unique mixtures of volatile compounds specific to their respective host plants. Taken together, the results support the hypothesis that differences among flies in their behavioral responses to host fruit odors represent key adaptations involved in sympatric host plant shifts, contributing to host specific mating and generating prezygotic reproductive isolation among members of the R. pomonella sibling species complex.
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Affiliation(s)
- Dong H Cha
- Department of Entomology, NYS Agricultural Experiment Station, Cornell University, Geneva, NY, 14456, USA
- USDA-ARS Yakima Agricultural Research Laboratory, Wapato, WA, 98951, USA
- USDA-ARS, 64 Nowelo Street, Hilo, HI, 96720, USA
| | - Shannon B Olsson
- Department of Entomology, NYS Agricultural Experiment Station, Cornell University, Geneva, NY, 14456, USA
- Naturalist-Inspired Chemical Ecology, National Centre for Biological Sciences, GKVK Campus, Tata Institute of Fundamental Research, Bellary Road, Bangalore, 560 065, India
| | - Wee L Yee
- USDA-ARS Yakima Agricultural Research Laboratory, Wapato, WA, 98951, USA
| | - Robert B Goughnour
- USDA-ARS Yakima Agricultural Research Laboratory, Wapato, WA, 98951, USA
| | - Glen R Hood
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46656, USA
| | - Monte Mattsson
- Department of Botany and Plant Pathology, Oregon State University, Cworvallis, OR, 97201, USA
| | - Dietmar Schwarz
- Department of Biology, Western Washington University, 510 High Street, MS 9160, Washington, 98225, USA
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46656, USA
| | - Charles E Linn
- Department of Entomology, NYS Agricultural Experiment Station, Cornell University, Geneva, NY, 14456, USA.
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48
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Friis G, Aleixandre P, Rodríguez-Estrella R, Navarro-Sigüenza AG, Milá B. Rapid postglacial diversification and long-term stasis within the songbird genus Junco: phylogeographic and phylogenomic evidence. Mol Ecol 2016; 25:6175-6195. [PMID: 27862578 DOI: 10.1111/mec.13911] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 09/01/2016] [Accepted: 11/02/2016] [Indexed: 01/04/2023]
Abstract
Natural systems composed of closely related taxa that vary in the degree of phenotypic divergence and geographic isolation provide an opportunity to investigate the rate of phenotypic diversification and the relative roles of selection and drift in driving lineage formation. The genus Junco (Aves: Emberizidae) of North America includes parapatric northern forms that are markedly divergent in plumage pattern and colour, in contrast to geographically isolated southern populations in remote areas that show moderate phenotypic divergence. Here, we quantify patterns of phenotypic divergence in morphology and plumage colour and use mitochondrial DNA genes, a nuclear intron, and genomewide SNPs to reconstruct the demographic and evolutionary history of the genus to infer relative rates of evolutionary divergence among lineages. We found that geographically isolated populations have evolved independently for hundreds of thousands of years despite little differentiation in phenotype, in sharp contrast to phenotypically diverse northern forms, which have diversified within the last few thousand years as a result of the rapid postglacial recolonization of North America. SNP data resolved young northern lineages into reciprocally monophyletic lineages, indicating low rates of gene flow even among closely related parapatric forms, and suggesting a role for strong genetic drift or multifarious selection acting on multiple loci in driving lineage divergence. Juncos represent a compelling example of speciation in action, where the combined effects of historical and selective factors have produced one of the fastest cases of speciation known in vertebrates.
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Affiliation(s)
- Guillermo Friis
- National Museum of Natural Sciences, Spanish National Research Council (CSIC), Madrid, 28006, Spain
| | - Pau Aleixandre
- National Museum of Natural Sciences, Spanish National Research Council (CSIC), Madrid, 28006, Spain
| | | | - Adolfo G Navarro-Sigüenza
- Museo de Zoología, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Borja Milá
- National Museum of Natural Sciences, Spanish National Research Council (CSIC), Madrid, 28006, Spain
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49
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Rull J, Tadeo E, Lasa R, Aluja M. The effect of winter length on survival and duration of dormancy of four sympatric species of Rhagoletis exploiting plants with different fruiting phenology. BULLETIN OF ENTOMOLOGICAL RESEARCH 2016; 106:818-826. [PMID: 27650278 DOI: 10.1017/s0007485316000717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Dormancy has been thoroughly studied for several species of economic importance in the genus Rhagoletis in temperate areas of North America and Europe. Much less is known on life history regulation for species inhabiting high-elevation areas in the subtropics at the southern extreme of their geographical range. Host plant phenology has been found to play a key role in generating allochronic isolation among sibling species and host races of Rhagoletis in the course of sympatric speciation, and has important implications for pest management. We compare the effect of winter length on survival to adult eclosion and dormancy duration among four species of Rhagoletis (three of them sympatric) exploiting hosts with different fruiting phenology in subtropical isolated highlands. Survival and duration of dormancy was found to be different among the four species. At 24°C, a very small proportion (<1%) of R. pomonella, R. turpiniae and R. zoqui completed development without becoming dormant, while in the case of R. solanophaga the majority of the population emerged after development within 40 days of pupation. Also, a large proportion of braconid parasitoids infesting Rhagoletis eggs and larvae emerged as adults without becoming dormant. Greatest survival after artificial winter was obtained for R. pomonella (50-60%) and R. zoqui (30%) after only four weeks at 5°C (a third of the time reported for studies on northern R. pomonella), while R. turpiniae, under identical environmental conditions experienced low adult emergence, and highest survival (11%) was recorded for flies exposed to 5°C during 10 and 12 weeks. For R. pomonella, there was a strong positive relationship between winter length and time to post-winter adult eclosion that was not observed for R. zoqui. In sum, for R. pomonella, mild winters in highland subtropical areas appear to select for flies better able to withstand longer periods of warm temperature before winter than flies exploiting late fruiting hosts and inhabiting northern latitudes. In the case of R. turpiniae and R. zoqui environmental cues such as fluctuations in humidity and/or different temperature thresholds (5°C) may play a more important role than winter length in life history regulation. Continuous host availability for R. solanophaga appears to have selected for non-diapausing flies. From an applied perspective our results are useful for handling flies in the laboratory to conduct research and suggest that non-diapausing strains of flies and parasitoids may be selected for SIT and innundative biological control programs.
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Affiliation(s)
- J Rull
- PROIMI Biotecnología-CONICET, LIEMEN-División Control Biológico de Plagas,Av. Belgrano y Pje. Caseros, T4001MVB San Miguel de Tucumán, Tucumán,Argentina
| | - E Tadeo
- Red de Manejo Biorracional de Plagas y Vectores, Instituto de Ecología,A.C., Xalapa, Veracruz 91070,México
| | - R Lasa
- Red de Manejo Biorracional de Plagas y Vectores, Instituto de Ecología,A.C., Xalapa, Veracruz 91070,México
| | - M Aluja
- Red de Manejo Biorracional de Plagas y Vectores, Instituto de Ecología,A.C., Xalapa, Veracruz 91070,México
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Yule KM, Koop JAH, Alexandre NM, Johnston LR, Whiteman NK. Population structure of a vector-borne plant parasite. Mol Ecol 2016; 25:3332-43. [PMID: 27154249 DOI: 10.1111/mec.13693] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/13/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022]
Abstract
Parasites are among the most diverse groups of life on Earth, yet complex natural histories often preclude studies of their speciation processes. The biology of parasitic plants facilitates in situ collection of data on both genetic structure and the mechanisms responsible for that structure. Here, we studied the role of mating, dispersal and establishment in host race formation of a parasitic plant. We investigated the population genetics of a vector-borne desert mistletoe (Phoradendron californicum) across two legume host tree species (Senegalia greggii and Prosopis velutina) in the Sonoran desert using microsatellites. Consistent with host race formation, we found strong host-associated genetic structure in sympatry, little genetic variation due to geographic site and weak isolation by distance. We hypothesize that genetic differentiation results from differences in the timing of mistletoe flowering by host species, as we found initial flowering date of individual mistletoes correlated with genetic ancestry. Hybrids with intermediate ancestry were detected genetically. Individuals likely resulting from recent, successful establishment events following dispersal between the host species were detected at frequencies similar to hybrids between host races. Therefore, barriers to gene flow between the host races may have been stronger at mating than at dispersal. We also found higher inbreeding and within-host individual relatedness values for mistletoes on the more rare and isolated host species (S. greggii). Our study spanned spatial scales to address how interactions with both vectors and hosts influence parasitic plant structure with implications for parasite virulence evolution and speciation.
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Affiliation(s)
- Kelsey M Yule
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Jennifer A H Koop
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Nicolas M Alexandre
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Lauren R Johnston
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA
| | - Noah K Whiteman
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E Lowell St, Tucson, AZ, 85721, USA.,Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, USA
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