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Mubayiwa M, Machekano H, Chidawanyika F, Mvumi BM, Segaiso B, Nyamukondiwa C. Sub-optimal host plants have developmental and thermal fitness costs to the invasive fall armyworm. FRONTIERS IN INSECT SCIENCE 2023; 3:1204278. [PMID: 38469519 PMCID: PMC10926449 DOI: 10.3389/finsc.2023.1204278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 09/04/2023] [Indexed: 03/13/2024]
Abstract
The fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) is a global invasive pest of cereals. Although this pest uses maize and sorghum as its main hosts, it is associated with a wide range of host plants due to its polyphagous nature. Despite the FAW's polyphagy being widely reported in literature, few studies have investigated the effects of the non-preferred conditions or forms (e.g., drought-stressed forms) of this pest's hosts on its physiological and ecological fitness. Thus, the interactive effects of biotic and abiotic stresses on FAW fitness costs or benefits have not been specifically investigated. We therefore assessed the effects of host plant quality on the developmental rates and thermal tolerance of the FAW. Specifically, we reared FAW neonates on three hosts (maize, cowpeas, and pearl millet) under two treatments per host plant [unstressed (well watered) and stressed (water deprived)] until the adult stage. Larval growth rates and pupal weights were determined. Thermal tolerance traits viz critical thermal maxima (CTmax), critical thermal minima (CTmin), heat knockdown time (HKDT), chill-coma recovery time (CCRT), and supercooling points (SCPs) were measured for the emerging adults from each treatment. The results showed that suboptimal diets significantly prolonged the developmental time of FAW larvae and reduced their growth rates and ultimate body weights, but did not impair their full development. Suboptimal diets (comprising non-cereal plants and drought-stressed cereal plants) increased the number of larval instars to eight compared to six for optimal natural diets (unstressed maize and pearl millet). Apart from direct effects, in all cases, suboptimal diets significantly reduced the heat tolerance of FAWs, but their effect on cold tolerance was recorded only in select cases (e.g., SCP). These results suggest host plant effects on the physical and thermal fitness of FAW, indicating a considerable degree of resilience against multiple stressors. This pest's resilience can present major drawbacks to its cultural management using suboptimal hosts (in crop rotations or intercrops) through its ability to survive on most host plants despite their water stress condition and gains in thermal fitness. The fate of FAW population persistence under multivariate environmental stresses is therefore not entirely subject to prior environmental host plant history or quality.
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Affiliation(s)
- Macdonald Mubayiwa
- Department of Biological Sciences and Biotechnology, Botswana International University of Science and Technology, Palapye, Botswana
| | - Honest Machekano
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Frank Chidawanyika
- Plant Health Department, International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
| | - Brighton M. Mvumi
- Department of Agricultural and Biosystems Engineering, Faculty of Agriculture, Environment and Food Systems, University of Zimbabwe, Harare, Zimbabwe
| | - Bame Segaiso
- Department of Biological Sciences and Biotechnology, Botswana International University of Science and Technology, Palapye, Botswana
| | - Casper Nyamukondiwa
- Department of Biological Sciences and Biotechnology, Botswana International University of Science and Technology, Palapye, Botswana
- Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
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2
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Riddell EA, Mutanen M, Ghalambor CK. Hydric effects on thermal tolerances influence climate vulnerability in a high-latitude beetle. GLOBAL CHANGE BIOLOGY 2023; 29:5184-5198. [PMID: 37376709 DOI: 10.1111/gcb.16830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023]
Abstract
Species' thermal tolerances are used to estimate climate vulnerability, but few studies consider the role of the hydric environment in shaping thermal tolerances. As environments become hotter and drier, organisms often respond by limiting water loss to lower the risk of desiccation; however, reducing water loss may produce trade-offs that lower thermal tolerances if respiration becomes inhibited. Here, we measured the sensitivity of water loss rate and critical thermal maximum (CTmax ) to precipitation in nature and laboratory experiments that exposed click beetles (Coleoptera: Elateridae) to acute- and long-term humidity treatments. We also took advantage of their unique clicking behavior to characterize subcritical thermal tolerances. We found higher water loss rates in the dry acclimation treatment compared to the humid, and water loss rates were 3.2-fold higher for individuals that had experienced a recent precipitation event compared to individuals that had not. Acute humidity treatments did not affect CTmax , but precipitation indirectly affected CTmax through its effect on water loss rates. Contrary to our prediction, we found that CTmax was negatively associated with water loss rate, such that individuals with high water loss rate exhibited a lower CTmax . We then incorporated the observed variation of CTmax into a mechanistic niche model that coupled leaf and click beetle temperatures to predict climate vulnerability. The simulations indicated that indices of climate vulnerability can be sensitive to the effects of water loss physiology on thermal tolerances; moreover, exposure to temperatures above subcritical thermal thresholds is expected to increase by as much as 3.3-fold under future warming scenarios. The correlation between water loss rate and CTmax identifies the need to study thermal tolerances from a "whole-organism" perspective that considers relationships between physiological traits, and the population-level variation in CTmax driven by water loss rate complicates using this metric as a straightforward proxy of climate vulnerability.
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Affiliation(s)
- Eric A Riddell
- Department of Ecology, Evolutionary, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Marko Mutanen
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Cameron K Ghalambor
- Department of Biology and Graduate Degree Program in Ecology, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
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3
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Araujo NDS, Perez R, Willot Q, Defrance M, Aron S. Facing lethal temperatures: Heat-shock response in desert and temperate ants. Ecol Evol 2023; 13:e10438. [PMID: 37720060 PMCID: PMC10500329 DOI: 10.1002/ece3.10438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 09/19/2023] Open
Abstract
Global climate changes may cause profound effects on species adaptation, particularly in ectotherms for whom even moderate warmer temperatures can lead to disproportionate heat failure. Still, several organisms evolved to endure high desert temperatures. Here, we describe the thermal tolerance survival and the transcriptomic heat stress response of three genera of desert (Cataglyphis, Melophorus, and Ocymyrmex) and two of temperate ants (Formica and Myrmica) and explore convergent and specific adaptations. We found heat stress led to either a reactive or a constitutive response in desert ants: Cataglyphis holgerseni and Melophorus bagoti differentially regulated very few transcripts in response to heat (0.12% and 0.14%, respectively), while Cataglyphis bombycina and Ocymyrmex robustior responded with greater expression alterations (respectively affecting 0.6% and 1.53% of their transcriptomes). These two responsive mechanisms-reactive and constitutive-were related to individual thermal tolerance survival and convergently evolved in distinct desert ant genera. Moreover, in comparison with desert species, the two temperate ants differentially expressed thousands of transcripts more in response to heat stress (affecting 8% and 12.71% of F. fusca and Myr. sabuleti transcriptomes). In summary, we show that heat adaptation in thermophilic ants involved changes in the expression response. Overall, desert ants show reduced transcriptional alterations even when under high thermal stress, and their expression response may be either constitutive or reactive to temperature increase.
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Affiliation(s)
| | - Rémy Perez
- Department of Evolutionary Biology & EcologyUniversité Libre de BruxellesBrusselsBelgium
| | - Quentin Willot
- Department of Evolutionary Biology & EcologyUniversité Libre de BruxellesBrusselsBelgium
- Zoophysiology, Department of BiologyAarhus UniversityAarhus‐CDenmark
| | - Matthieu Defrance
- Interuniversity Institute of Bioinformatics in BrusselsUniversité Libre de BruxellesBrusselsBelgium
| | - Serge Aron
- Department of Evolutionary Biology & EcologyUniversité Libre de BruxellesBrusselsBelgium
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4
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Leong CM, Hui TY, Guénard B. The role of body mass in limiting post heat-coma recovery ability in terrestrial ectotherms. Ecol Evol 2023; 13:e10218. [PMID: 37361898 PMCID: PMC10288262 DOI: 10.1002/ece3.10218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/03/2023] [Accepted: 06/05/2023] [Indexed: 06/28/2023] Open
Abstract
Under global warming, animal species show shrinking body size responses, cascading deep changes in community structure and ecosystem functions. Although the exact physiological mechanisms behind this phenomenon remain unsolved, smaller individuals may benefit from warming climate more than larger ones. Heat-coma, a physiological state with severe consequences on locomotion ability, is often considered as an "ecological death" scenario under which individuals are unable to escape and exposed to predation, further heat injury, and other hazards. Species are expected to increasingly encounter heat-coma temperature thresholds under warming climate, and body size may be an important trait for thermoregulation in particular for ectotherms. The relationship between heat-coma and shrinking body size remains, however, unclear. Yet, recovery after short-term heat-coma is possible, but little is known about its importance in thermal adaptation and how organismal size correlates with post heat-coma recovery. Here, using ants as a model system, we firstly examined the fate of heat-comatose individuals under field conditions to quantify the ecological benefits of post heat-coma recovery. Then, we quantified ants' recovery ability after heat-coma using a dynamic thermal assay in the laboratory and asked if thermal resilience varies between species with different body mass. Our results confirm that heat-coma represents an inherent ecological death where individuals failed to recover from coma suffer strong predation pressure. Additionally, following phylogenetic signals inclusion, organisms with small mass were more likely to recover, supporting the temperature-size rule in thermal adaptation and recent studies showing a decrease in body size composition of ectotherm community under warmer climatic conditions. Body size as a fundamental trait in ecology thus affects ectotherm survival under thermal stress, which may drive species body size adaptations and community composition under future warming scenarios.
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Affiliation(s)
- Chi Man Leong
- School of Biological SciencesThe University of Hong KongHong Kong SARChina
- Present address:
Environmental Science Programme, Department of Life Sciences, Faculty of Science and TechnologyBeijing Normal University‐Hong Kong Baptist University United International CollegeZhuhaiChina
| | - Tin Yan Hui
- School of Biological SciencesThe University of Hong KongHong Kong SARChina
- The Swire Institute of Marine ScienceThe University of Hong KongHong Kong SARChina
- Present address:
Science UnitLingnan UniversityHong Kong SARChina
| | - Benoit Guénard
- School of Biological SciencesThe University of Hong KongHong Kong SARChina
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5
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Muluvhahothe MM, Joubert E, Foord SH. Thermal tolerance responses of the two-spotted stink bug, Bathycoelia distincta (Hemiptera: Pentatomidae), vary with life stage and the sex of adults. J Therm Biol 2023; 111:103395. [PMID: 36585076 DOI: 10.1016/j.jtherbio.2022.103395] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/22/2022] [Accepted: 11/22/2022] [Indexed: 12/09/2022]
Abstract
Temperature tolerance is an essential component of insect fitness, and its understanding can provide a predictive framework for their distribution and abundance. The two-spotted stink bug, Bathycoelia distincta Distant, is a significant pest of macadamia. The main goal of this study was to investigate the thermal tolerance of B. distincta across different life stages. Thermal tolerance indices investigated included critical thermal maximum (CTmax), critical thermal minimum (CTmin), effects of acclimation on CTmax and CTmin at 20, 25, and 30 °C, and rapid heat hardening (RHH), and rapid cold hardening (RCH). The Kruskal-Wallis test was used to explore the effects of life stage and acclimation on CTmax and CTmin and Generalized Linear Models (GLM) for the probability of survival after pre-exposure to RHH at 41 °C for 2 h and RCH at -8 °C for 2 h. CTmax and CTmin varied significantly between life stages at all acclimation temperatures, but CTmin (3.5 °C) varied more than CTmax (2.1 °C). Higher acclimation temperatures resulted in larger variations between life stages for both CTmax and CTmin. A significant acclimation response was observed for the CTmax of instar 2 (1.7 °C) and CTmin of females (2.7 °C) across acclimation temperatures (20-30 °C). Pre-exposure significantly improved the heat and cold survival probability of instar 2 and the cold survival probability of instar 3 and males. The response between life stages was more variable in RCH than in RHH. Instar 2 appeared to be the most thermally plastic life stage of B. distincta. These results suggest that the thermal plastic traits of B. distincta life stages may enable this pest to survive in temperature regimes under the ongoing climate change, with early life stages (except for instar 2) more temperature sensitive than later life stages.
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Affiliation(s)
- Mulalo M Muluvhahothe
- SARChI-Chair on Biodiversity Value and Change, Department of Biological Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa.
| | - Elsje Joubert
- Levubu Centre for Excellence, PO Box 121, Levubu, 0929, South Africa
| | - Stefan H Foord
- SARChI-Chair on Biodiversity Value and Change, Department of Biological Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa
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6
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Perez R, Benbachir M, Decroo C, Mascolo C, Wattiez R, Aron S. Cataglyphis desert ants use distinct behavioral and physiological adaptations to cope with extreme thermal conditions. J Therm Biol 2023; 111:103397. [PMID: 36585078 DOI: 10.1016/j.jtherbio.2022.103397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/25/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022]
Abstract
Some ant species live in hot and arid environments, such as deserts and savannas. Worker polymorphism-variation in worker size and/or morphology within colonies-is adaptive in such ecosystems because it enhances resistance to heat stress and increases the efficiency of resource exploitation. However, species with small, monomorphic workers are also frequently found in these environments. How species with distinct worker size and degrees of polymorphism deal with such stressful environments remains poorly studied. We investigated the behavioral, physiological, and molecular adaptations that may enhance heat and desiccation tolerance in two sympatric species of Cataglyphis desert ants that differ dramatically in worker size and polymorphism: C. viatica is polymorphic, while C. cubica is small and monomorphic. We found that worker size, water content, water loss, and protein regulation play a key role in thermal resistance. (i) Large C. viatica workers better tolerated heat and desiccation stress than did small C. viatica or C. cubica workers. The former had greater water content and lost proportionally less water to evaporation under thermal stress. (ii) Despite their similar size distribution, workers of C. cubica are more heat tolerant than small C. viatica. This higher degree of tolerance likely stemmed from C. cubica workers having greater relative water content. (iii) Under thermal stress, small C. viatica workers metabolized larger quantities of fat and differentially expressed proteins involved in cellular homeostasis. In contrast, C. cubica downregulated the expression of numerous proteins involved in mitochondrial respiration likely reducing ROS accumulation. (iv) Consistent with these results, large C. viatica workers remained active throughout the day; C. cubica workers displayed a bimodal activity pattern, and small C. viatica remained poorly active outside the nest. Our study shows that ecologically similar ant species with different degrees of worker size polymorphism evolved distinct strategies for coping with extreme heat conditions.
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Affiliation(s)
- Rémy Perez
- Department of Evolutionary Biology & Ecology, Université Libre de Bruxelles, B-1050, Brussels, Belgium.
| | - Mohammed Benbachir
- Department of Evolutionary Biology & Ecology, Université Libre de Bruxelles, B-1050, Brussels, Belgium
| | - Corentin Decroo
- Department of Proteomics and Microbiology, Université de Mons, B-7000, Mons, Belgium
| | - Cyril Mascolo
- Department of Proteomics and Microbiology, Université de Mons, B-7000, Mons, Belgium
| | - Ruddy Wattiez
- Department of Proteomics and Microbiology, Université de Mons, B-7000, Mons, Belgium
| | - Serge Aron
- Department of Evolutionary Biology & Ecology, Université Libre de Bruxelles, B-1050, Brussels, Belgium
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7
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Sato A, Takahashi Y. Responses in thermal tolerance and daily activity rhythm to urban stress in Drosophila suzukii. Ecol Evol 2022; 12:e9616. [PMCID: PMC9744627 DOI: 10.1002/ece3.9616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 10/27/2022] [Accepted: 11/23/2022] [Indexed: 12/15/2022] Open
Abstract
Cities experience changes in abiotic factors, such as warming, increases in noise and light. These changes can lead to phenotypic changes. Several studies have revealed that altered environments change phenotypes in plants and animals in cities. However, limited studies have isolated evolutionary from nongenetic changes. Here, we analyzed the evolution of thermal tolerance and diurnal activity patterns in the urban population of the fruit pest, Drosophila suzukii. Urban and rural isofemale lines were reared under constant conditions. We compared the lower and upper thermal limits (CTmin and CTmax, respectively), and effects of temperature exposure on the thermal limits of urban and rural populations. Common garden experiments showed that urban populations exhibit a lower CTmin than rural populations, suggesting genetic difference in CTmin among populations. On the other hand, the difference in CTmax between urban and rural populations was not significant. Exposure to cold temperature did not affect CTmin in both urban and rural populations. In contrast, exposure to hot temperature increased CTmax especially in urban population, suggesting that urban populations evolved in response to urban heat. We also investigated the daily activity patterns of urban and rural populations and the effect of lifelong artificial light at night on daily activity. We found that night‐time light (dim light) reduced the total amount of activity compared to dark night condition. In addition, dim light at night altered the daily rhythm of activity and increased the activity rate at night. The effect of night light on total activity was less in urban than that in rural populations, suggesting that populations in cities evolved to mitigate decreased activity under night light. Our results showed that environmental temperature and artificial light at night evolutionarily and plastically influence ecologically important traits, such as temperature tolerance and diurnal activity.
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Affiliation(s)
- Ayame Sato
- Graduate School of Science and EngineeringChiba UniversityChibaJapan
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8
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Global change drivers synergize with the negative impacts of non-native invasive ants on native seed-dispersing ants. Biol Invasions 2022. [DOI: 10.1007/s10530-022-02943-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Atkins RL, Clancy KM, Ellis WT, Osenberg CW. Thermal Traits Vary with Mass and across Populations of the Marsh Periwinkle, Littoraria irrorata. THE BIOLOGICAL BULLETIN 2022; 242:173-196. [PMID: 35767414 DOI: 10.1086/719850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
AbstractPhysiological processes influence how individuals perform in various environmental contexts. The basis of such processes, metabolism, scales allometrically with body mass and nonlinearly with temperature, as described by a thermal performance curve. Past studies of thermal performance curves tend to focus on effects of temperature on a single body size or population, rather than variation in the thermal performance curve across sizes and populations. Here, we estimate intraspecific variation in parameters of the thermal performance curve in the salt marsh gastropod Littoraria irrorata. First, we quantify the thermal performance curve for respiration rate as a function of both temperature and body size in Littoraria and evaluate whether the thermal parameters and body size scaling are interdependent. Next, we quantify how parameters in the thermal performance curve for feeding rate vary between three Littoraria populations that occur along a latitudinal gradient. Our work suggests that the thermal traits describing Littoraria respiration are dependent on body mass and that both the thermal traits and the mass scaling of feeding vary across sites. We found limited evidence to suggest that mass scaling of Littoraria feeding or respiration rates depends on temperature. Variation in the thermal performance curves interacts with the size structure of the Littoraria population to generate divergent population-level responses to temperature. These results highlight the importance of considering variation in population size structure and physiological allometry when attempting to predict how temperature change will affect physiological responses and consumer-resource interactions.
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10
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Pardee GL, Griffin SR, Stemkovski M, Harrison T, Portman ZM, Kazenel MR, Lynn JS, Inouye DW, Irwin RE. Life-history traits predict responses of wild bees to climate variation. Proc Biol Sci 2022; 289:20212697. [PMID: 35440209 PMCID: PMC9019520 DOI: 10.1098/rspb.2021.2697] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Life-history traits, which are physical traits or behaviours that affect growth, survivorship and reproduction, could play an important role in how well organisms respond to environmental change. By looking for trait-based responses within groups, we can gain a mechanistic understanding of why environmental change might favour or penalize certain species over others. We monitored the abundance of at least 154 bee species for 8 consecutive years in a subalpine region of the Rocky Mountains to ask whether bees respond differently to changes in abiotic conditions based on their life-history traits. We found that comb-building cavity nesters and larger bodied bees declined in relative abundance with increasing temperatures, while smaller, soil-nesting bees increased. Further, bees with narrower diet breadths increased in relative abundance with decreased rainfall. Finally, reduced snowpack was associated with reduced relative abundance of bees that overwintered as prepupae whereas bees that overwintered as adults increased in relative abundance, suggesting that overwintering conditions might affect body size, lipid content and overwintering survival. Taken together, our results show how climate change may reshape bee pollinator communities, with bees with certain traits increasing in abundance and others declining, potentially leading to novel plant-pollinator interactions and changes in plant reproduction.
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Affiliation(s)
- Gabriella L Pardee
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27607, USA.,Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA.,Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Sean R Griffin
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Michael Stemkovski
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA.,Department of Biology and Ecology Center, Utah State University, Logan, UT 84322, USA
| | - Tina Harrison
- Department of Biology, University of Louisiana, Lafayette, LA 70501, USA
| | - Zachary M Portman
- Department of Entomology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108
| | - Melanie R Kazenel
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Joshua S Lynn
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA.,Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.,Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - David W Inouye
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA.,Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Rebecca E Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27607, USA.,Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
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11
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Nascimento G, Câmara T, Arnan X. Critical thermal limits in ants and their implications under climate change. Biol Rev Camb Philos Soc 2022; 97:1287-1305. [PMID: 35174946 DOI: 10.1111/brv.12843] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 11/28/2022]
Abstract
Critical thermal limits (CTLs) constrain the performance of organisms, shaping their abundance, current distributions, and future distributions. Consequently, CTLs may also determine the quality of ecosystem services as well as organismal and ecosystem vulnerability to climate change. As some of the most ubiquitous animals in terrestrial ecosystems, ants are important members of ecological communities. In recent years, an increasing body of research has explored ant physiological thermal limits. However, these CTL data tend to centre on a few species and biogeographical regions. To encourage an expansion of perspectives, we herein review the factors that determine ant CTLs and examine their effects on present and future species distributions and ecosystem processes. Special emphasis is placed on the implications of CTLs for safeguarding ant diversity and ant-mediated ecosystem services in the future. First, we compile, quantify, and categorise studies on ant CTLs based on study taxon, biogeographical region, methodology, and study question. Second, we use this comprehensive database to analyse the abiotic and biotic factors shaping ant CTLs. Our results highlight how CTLs may affect future distribution patterns and ecological performance in ants. Additionally, we identify the greatest remaining gaps in knowledge and create a research roadmap to promote rapid advances in this field of study.
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Affiliation(s)
- Geraldo Nascimento
- Universidade de Pernambuco - Campus Garanhuns, Rua Capitão Pedro Rodrigues, 105 - São José, Garanhuns, 55294-902, Brazil.,Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, BR 203, KM 2 - Vila Eduardo, Petrolina, 56328-900, Brazil
| | - Talita Câmara
- Universidade de Pernambuco - Campus Garanhuns, Rua Capitão Pedro Rodrigues, 105 - São José, Garanhuns, 55294-902, Brazil.,Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, BR 203, KM 2 - Vila Eduardo, Petrolina, 56328-900, Brazil
| | - Xavier Arnan
- Universidade de Pernambuco - Campus Garanhuns, Rua Capitão Pedro Rodrigues, 105 - São José, Garanhuns, 55294-902, Brazil.,Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, BR 203, KM 2 - Vila Eduardo, Petrolina, 56328-900, Brazil.,CREAF, Campus de Bellaterra (UAB) Edifici C, Cerdanyola del Vallès, 08193, Spain
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12
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Leaf-cutting ants' critical and voluntary thermal limits show complex responses to size, heating rates, hydration level, and humidity. J Comp Physiol B 2021; 192:235-245. [PMID: 34837117 PMCID: PMC8894219 DOI: 10.1007/s00360-021-01413-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 08/30/2021] [Accepted: 10/03/2021] [Indexed: 11/25/2022]
Abstract
Thermal variation has complex effects on organisms and they respond to these effects through combined behavioral and physiological mechanisms. However, it is less clear how these traits combine in response to changes in body condition (e.g., size, hydration) and environmental factors that surround the heating process (e.g., relative humidity, start temperatures, heating rates). We tested whether these body conditions and environmental factors influence sequentially measured Voluntary Thermal Maxima (VTmax) and Critical Thermal Maxima, (CTmax) in leaf-cutting ants (Atta sexdens rubropilosa, Forel, 1908). VTmax and CTmax reacted differently to changes in body size and relative humidity, but exhibited similar responses to hydration level, start temperature, and heating rate. Strikingly, the VTmax of average-sized workers was closer to their CTmax than the VTmax of their smaller and bigger sisters, suggesting foragers maintain normal behavior at higher temperatures than sister ants that usually perform tasks within the colony. Previous experiments based on hot plate designs might overestimate ants’ CTmax. VTmax and CTmax may respond concomitantly or not to temperature rises, depending on body condition and environmental factors.
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13
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Villalta I, Oms CS, Angulo E, Molinas-González CR, Devers S, Cerdá X, Boulay R. Does social thermal regulation constrain individual thermal tolerance in an ant species? J Anim Ecol 2020; 89:2063-2076. [PMID: 32445419 DOI: 10.1111/1365-2656.13268] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 05/06/2020] [Indexed: 11/30/2022]
Abstract
In ants, social thermal regulation is the collective maintenance of a nest temperature that is optimal for individual colony members. In the thermophilic ant Aphaenogaster iberica, two key behaviours regulate nest temperature: seasonal nest relocation and variable nest depth. Outside the nest, foragers must adapt their activity to avoid temperatures that exceed their thermal limits. It has been suggested that social thermal regulation constrains physiological and morphological thermal adaptations at the individual level. We tested this hypothesis by examining the foraging rhythms of six populations of A. iberica, which were found at different elevations (from 100 to 2,000 m) in the Sierra Nevada mountain range of southern Spain. We tested the thermal resistance of individuals from these populations under controlled conditions. Janzen's climatic variability hypothesis (CVH) states that greater climatic variability should select for organisms with broader temperature tolerances. We found that the A. iberica population at 1,300 m experienced the most extreme temperatures and that ants from this population had the highest heat tolerance (LT50 = 57.55°C). These results support CVH's validity at microclimatic scales, such as the one represented by the elevational gradient in this study. Aphaenogaster iberica maintains colony food intake levels across different elevations and mean daily temperatures by shifting its rhythm of activity. This efficient colony-level thermal regulation and the significant differences in individual heat tolerance that we observed among the populations suggest that behaviourally controlled thermal regulation does not constrain individual physiological adaptations for coping with extreme temperatures.
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Affiliation(s)
- Irene Villalta
- Institut de Recherche sur la Biologie de l'Insecte, Université de Tours, Parc de Grandmont, Tours, France.,Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | - Cristela Sánchez Oms
- Institut de Recherche sur la Biologie de l'Insecte, Université de Tours, Parc de Grandmont, Tours, France.,Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | - Elena Angulo
- Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | | | - Séverine Devers
- Institut de Recherche sur la Biologie de l'Insecte, Université de Tours, Parc de Grandmont, Tours, France
| | - Xim Cerdá
- Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | - Raphaël Boulay
- Institut de Recherche sur la Biologie de l'Insecte, Université de Tours, Parc de Grandmont, Tours, France
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