1
|
Groot AT, Blankers T, Halfwerk W, Burdfield Steel E. The Evolutionary Importance of Intraspecific Variation in Sexual Communication Across Sensory Modalities. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:21-40. [PMID: 37562048 DOI: 10.1146/annurev-ento-030223-111608] [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: 08/12/2023]
Abstract
The evolution of sexual communication is critically important in the diversity of arthropods, which are declining at a fast pace worldwide. Their environments are rapidly changing, with increasing chemical, acoustic, and light pollution. To predict how arthropod species will respond to changing climates, habitats, and communities, we need to understand how sexual communication systems can evolve. In the past decades, intraspecific variation in sexual signals and responses across different modalities has been identified, but never in a comparative way. In this review, we identify and compare the level and extent of intraspecific variation in sexual signals and responses across three different modalities, chemical, acoustic, and visual, focusing mostly on insects. By comparing causes and possible consequences of intraspecific variation in sexual communication among these modalities, we identify shared and unique patterns, as well as knowledge needed to predict the evolution of sexual communication systems in arthropods in a changing world.
Collapse
Affiliation(s)
- Astrid T Groot
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands; , ,
| | - Thomas Blankers
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands; , ,
| | - Wouter Halfwerk
- Amsterdam Institute for Life and Environment (A-LIFE), VU Amsterdam, Netherlands;
| | - Emily Burdfield Steel
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands; , ,
| |
Collapse
|
2
|
Morimoto J, Wenzel M, Derous D, Henry Y, Colinet H. The transcriptomic signature of responses to larval crowding in Drosophila melanogaster. INSECT SCIENCE 2023; 30:539-554. [PMID: 36115064 PMCID: PMC10947363 DOI: 10.1111/1744-7917.13113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/22/2022] [Accepted: 08/27/2022] [Indexed: 06/15/2023]
Abstract
Intraspecific competition at the larval stage is an important ecological factor affecting life-history, adaptation and evolutionary trajectory in holometabolous insects. However, the molecular pathways underpinning these ecological processes are poorly characterized. We reared Drosophila melanogaster at three egg densities (5, 60, and 300 eggs/mL) and sequenced the transcriptomes of pooled third-instar larvae. We also examined emergence time, egg-to-adult viability, adult mass, and adult sex-ratio at each density. Medium crowding had minor detrimental effects on adult phenotypes compared to low density and yielded 24 differentially expressed genes (DEGs), including several chitinase enzymes. In contrast, high crowding had substantial detrimental effects on adult phenotypes and yielded 2107 DEGs. Among these, upregulated gene sets were enriched in sugar, steroid and amino acid metabolism as well as DNA replication pathways, whereas downregulated gene sets were enriched in ABC transporters, taurine, Toll/Imd signaling, and P450 xenobiotics metabolism pathways. Overall, our findings show that larval crowding has a large consistent effect on several molecular pathways (i.e., core responses) with few pathways displaying density-specific regulation (i.e., idiosyncratic responses). This provides important insights into how holometabolous insects respond to intraspecific competition during development.
Collapse
Affiliation(s)
- Juliano Morimoto
- School of Biological SciencesUniversity of AberdeenAberdeenUnited Kingdom
- Programa de Pós‐graduação em Ecologia e ConservaçãoUniversidade Federal do ParanáCuritibaBrazil
- Institute of MathematicsKing's CollegeUniversity of AberdeenAberdeenUnited Kingdom
| | - Marius Wenzel
- School of Biological SciencesUniversity of AberdeenAberdeenUnited Kingdom
| | - Davina Derous
- School of Biological SciencesUniversity of AberdeenAberdeenUnited Kingdom
| | - Youn Henry
- CNRS, ECOBIO (Ecosystèmes, biodiversité, évolution)—UMR 6553University of RennesRennesFrance
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Herve Colinet
- CNRS, ECOBIO (Ecosystèmes, biodiversité, évolution)—UMR 6553University of RennesRennesFrance
| |
Collapse
|
3
|
Narasimhan A, Kapila R, Meena A, Prasad NG. Consequences of adaptation to larval crowding on sexual and fecundity selection in Drosophila melanogaster. J Evol Biol 2023; 36:730-737. [PMID: 36946997 DOI: 10.1111/jeb.14168] [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: 07/07/2021] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 03/23/2023]
Abstract
Sexual selection is a major force influencing the evolution of sexually reproducing species. Environmental factors such as larval density can manipulate adult condition and influence the direction and strength of sexual selection. While most studies on the influence of larval crowding on sexual selection are either correlational or single-generation manipulations, it is unclear how evolution under chronic larval crowding affects sexual selection. To answer this, we measured the strength of sexual selection on male and female Drosophila melanogaster that had evolved under chronic larval crowding for over 250 generations in the laboratory, along with their controls which had never experienced crowding, in a common garden high-density environment. We measured selection coefficients on male mating success and sex-specific reproductive success, as separate estimates allowed dissection of sex-specific effects. We show that experimental evolution under chronic larval crowding decreases the strength of sexual and fecundity selection in males but not in females, relative to populations experiencing crowding for the first time. The effect of larval crowding in reducing reproductive success is almost twice in females than in males. Our study highlights the importance of studying how evolution in a novel, stressful environment can shape adult fitness in organisms.
Collapse
Affiliation(s)
- Aaditya Narasimhan
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | -
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Rohit Kapila
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Abhishek Meena
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | -
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Nagaraj Guru Prasad
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| |
Collapse
|
4
|
Johnson TL, Elgar MA, Symonds MRE. Movement and olfactory signals: Sexually dimorphic antennae and female flightlessness in moths. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.919093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Darwin argued a role for sexual selection in the evolution of male sensory structures, including insect antennae, the strength of which will depend upon the importance of early arrival at receptive females. There is remarkable variation in the nature and degree of sexual dimorphism in moth antennae, with males of some species having spectacular, feathery antennae. Although it is widely assumed that these elaborate structures provide greater sensitivity to chemical signals (sex pheromones), the factors underlying the interspecific diversity in male antennal structure and size are poorly understood. Because male antennal morphology may be affected by several female life–history traits, including flight ability, we conducted a phylogenetic comparative analysis to test how these traits are linked, using data from 93 species of moths across 11 superfamilies. Our results reveal that elaborate antennae in males have evolved more frequently in species where females are monandrous. Further, female loss of flight ability evolved more frequently in species where males have elaborate antennae. These results suggest that elaborate antennae have evolved in response to more intense male competition, arising from female monandry, and that the evolution of elaborate antennae in males has, in turn, shaped the evolution of female flightlessness.
Collapse
|
5
|
Morimoto J, Barcellos R, Schoborg TA, Nogueira LP, Colaço MV. Assessing Anatomical Changes in Male Reproductive Organs in Response to Larval Crowding Using Micro-computed Tomography Imaging. NEOTROPICAL ENTOMOLOGY 2022; 51:526-535. [PMID: 35789989 PMCID: PMC9304064 DOI: 10.1007/s13744-022-00976-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Ecological conditions shape (adaptive) responses at the molecular, anatomical, and behavioral levels. Understanding these responses is key to predict the outcomes of intra- and inter-specific competitions and the evolutionary trajectory of populations. Recent technological advances have enabled large-scale molecular (e.g., RNAseq) and behavioral (e.g., computer vision) studies, but the study of anatomical responses to ecological conditions has lagged behind. Here, we highlight the role of X-ray micro-computed tomography (micro-CT) in generating in vivo and ex vivo 3D imaging of anatomical structures, which can enable insights into adaptive anatomical responses to ecological environments. To demonstrate the application of this method, we manipulated the larval density of Drosophila melanogaster Meigen flies and applied micro-CT to investigate the anatomical responses of the male reproductive organs to varying intraspecific competition levels during development. Our data is suggestive of two classes of anatomical responses which broadly agree with sexual selection theory: increasing larval density led to testes and ejaculatory duct to be overall larger (in volume), while the volume of accessory glands and, to a lesser extent, ejaculatory duct decreased. These two distinct classes of anatomical responses might reflect shared developmental regulation of the structures of the male reproductive system. Overall, we show that micro-CT can be an important tool to advance the study of anatomical (adaptive) responses to ecological environments.
Collapse
Affiliation(s)
- Juliano Morimoto
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
- Institute of Mathematics, University of Aberdeen, Aberdeen, UK.
- Programa de Pós-Graduação Em Ecologia E Conservação, Universidade Federal Do Paraná, Curitiba, Paraná, Brazil.
- Institute of Differential Geometry, Riemann Centre for Geometry and Physics, Leibniz Universität Hannover, Hannover, Germany.
| | - Renan Barcellos
- COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Todd A Schoborg
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
| | | | - Marcos Vinicius Colaço
- Laboratory of Applied Physics to Biomedical Sciences, Physics Institute, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
6
|
Cronin AD, Smit JAH, Muñoz MI, Poirier A, Moran PA, Jerem P, Halfwerk W. A comprehensive overview of the effects of urbanisation on sexual selection and sexual traits. Biol Rev Camb Philos Soc 2022; 97:1325-1345. [PMID: 35262266 PMCID: PMC9541148 DOI: 10.1111/brv.12845] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 02/11/2022] [Accepted: 02/16/2022] [Indexed: 12/18/2022]
Abstract
Urbanisation can affect mating opportunities and thereby alter inter- and intra-sexual selection pressures on sexual traits. Biotic and abiotic urban conditions can influence an individual's success in pre- and post-copulatory mating, for example through impacts on mate attraction and mate preference, fertilisation success, resource competition or rival interactions. Divergent sexual selection pressures can lead to differences in behavioural, physiological, morphological or life-history traits between urban and non-urban populations, ultimately driving adaptation and speciation. Most studies on urban sexual selection and mating interactions report differences between urban and non-urban populations or correlations between sexual traits and factors associated with increased urbanisation, such as pollution, food availability and risk of predation and parasitism. Here we review the literature on sexual selection and sexual traits in relation to urbanisation or urban-associated conditions. We provide an extensive list of abiotic and biotic factors that can influence processes involved in mating interactions, such as signal production and transmission, mate choice and mating opportunities. We discuss all relevant data through the lens of two, non-mutually exclusive theories on sexual selection, namely indicator and sensory models. Where possible, we indicate whether these models provide the same or different predictions regarding urban-adapted sexual signals and describe different experimental designs that can be useful for the different models as well as to investigate the drivers of sexual selection. We argue that we lack a good understanding of: (i) the factors driving urban sexual selection; (ii) whether reported changes in traits result in adaptive benefits; and (iii) whether these changes reflect a short-term ecological, or long-term evolutionary response. We highlight that urbanisation provides a unique opportunity to study the process and outcomes of sexual selection, but that this requires a highly integrative approach combining experimental and observational work.
Collapse
Affiliation(s)
- Andrew D Cronin
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Judith A H Smit
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Matías I Muñoz
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Armand Poirier
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Peter A Moran
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Paul Jerem
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| | - Wouter Halfwerk
- Department of Ecological Sciences, Vrije Universiteit, De Boelelaan 1085, Amsterdam, 1081 HV, The Netherlands
| |
Collapse
|
7
|
Pham HT, Elgar MA, van Lieshout E, McNamara KB. Experimental immune challenges reduce the quality of male antennae and female pheromone output. Sci Rep 2022; 12:3578. [PMID: 35246550 PMCID: PMC8897396 DOI: 10.1038/s41598-022-07100-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/01/2022] [Indexed: 11/17/2022] Open
Abstract
Sexual signalling is a key feature of reproductive investment, yet the effects of immune system activation on investment into chemical signalling, and especially signal receiver traits such as antennae, are poorly understood. We explore how upregulation of juvenile immunity affects male antennal functional morphology and female pheromone attractiveness in the gumleaf skeletonizer moth, Uraba lugens. We injected final-instar larvae with a high or low dose of an immune elicitor or a control solution and measured male antennal morphological traits, gonad investment and female pheromone attractiveness. Immune activation affected male and female signalling investment: immune challenged males had a lower density of antennal sensilla, and the pheromone of immune-challenged females was less attractive to males than their unchallenged counterparts. Immune challenge affected female investment into ovary development but not in a linear, dose-dependent manner. While there was no effect of immune challenge on testes size, there was a trade-off between male pre- and post-copulatory investment: male antennal length was negatively correlated with testes size. Our study highlights the costs of elaborate antennae and pheromone production and demonstrates the capacity for honest signalling in species where the costs of pheromone production were presumed to be trivial.
Collapse
Affiliation(s)
- Hieu T Pham
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Entomology, Faculty of Agronomy, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Mark A Elgar
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Emile van Lieshout
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kathryn B McNamara
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
| |
Collapse
|
8
|
Morimoto J, Than AT, Nguyen B, Lundbäck I, Dinh H, Ponton F. Density-by-diet interactions during larval development shape adult life-history trait expression and fitness in a polyphagous fly. Am Nat 2022; 199:E170-E185. [DOI: 10.1086/718910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
9
|
Gascoigne SJL, Uwera Nalukwago DI, Barbosa F. Larval Density, Sex, and Allocation Hierarchy Affect Life History Trait Covariances in a Bean Beetle. Am Nat 2022; 199:291-301. [DOI: 10.1086/717639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Samuel J. L. Gascoigne
- Department of Biology, Lake Forest College, Lake Forest, Illinois 60045
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford OX1 3SZ, United Kingdom
| | | | - Flavia Barbosa
- Department of Biology, Lake Forest College, Lake Forest, Illinois 60045
| |
Collapse
|
10
|
Liu J, He XZ, Zheng XL, Zhang Y, Wang Q. Pupal Cues Increase Sperm Production but Not Testis Size in an Insect. INSECTS 2021; 12:679. [PMID: 34442245 PMCID: PMC8396453 DOI: 10.3390/insects12080679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/13/2022]
Abstract
Theoretic and empirical studies show that social surroundings experienced by male insects during their larval or adult stage can influence their testicular investment in diverse ways. Although insect pupae do not feed and crawl, they can communicate using sex-specific and/or non-sex specific cues. Yet, it is unknown, in any insect, whether and how male pupae can fine-tune their resource allocation to sperm production and testis size in response to socio-sexual environments. We investigated this question using a moth, Ephestia kuehniella, which produces fertile eupyrene sperm and unfertile apyrene sperm. We held male pupae individually or in groups with different sex ratios, and dissected adults upon eclosion, measured their testis size, and counted both types of sperm. We demonstrated that after exposure to conspecific pupal cues regardless of sex, male pupae increased production of eupyrenes and apyrenes at the same rate but kept testis size unchanged. We suggest that testis size is fixed after pupation because most morphological traits are formed during the larval stage, allowing little room for pupae to adjust testis size. Like adults, male pupae with fully grown testes have sufficient resources to produce more sperm of both types according to the perceived increase in sperm competition risk.
Collapse
Affiliation(s)
- Junyan Liu
- School of Agriculture and Environment, Massey University, Palmerston North 4410, New Zealand; (J.L.); (X.Z.H.)
| | - Xiong Z. He
- School of Agriculture and Environment, Massey University, Palmerston North 4410, New Zealand; (J.L.); (X.Z.H.)
| | - Xia-Lin Zheng
- Guangxi Key Laboratory of Agric-Environment and Agric-Products Safety, National Demonstration Centre for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (X.-L.Z.); (Y.Z.)
| | - Yujing Zhang
- Guangxi Key Laboratory of Agric-Environment and Agric-Products Safety, National Demonstration Centre for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China; (X.-L.Z.); (Y.Z.)
| | - Qiao Wang
- School of Agriculture and Environment, Massey University, Palmerston North 4410, New Zealand; (J.L.); (X.Z.H.)
| |
Collapse
|
11
|
Miller CW, Joseph PN, Emberts Z. Trade-offs between weapons and testes do not manifest at high social densities. J Evol Biol 2021; 34:726-735. [PMID: 33870571 DOI: 10.1111/jeb.13790] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/23/2021] [Accepted: 03/30/2021] [Indexed: 01/28/2023]
Abstract
Social conditions can alter the allocation of resources to reproductive traits. For example, an increase in social density during development is frequently associated with an increase in the testes mass of males. Sperm competition theory assumes that increased investment in testes should come at the expense of investing into precopulatory traits, such as sexually selected weaponry. However, much remains unknown about the role of the social context on the concurrent, relative investment in both testes and weapons. We found that the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae), grew nearly 20% larger testes when raised in high social densities. In addition to manipulating social density, we used autotomy (limb loss) to limit investment in their hindlimb weapon during development. At low densities, we found that those that lost a weapon during development grew larger testes by adulthood, supporting previous work demonstrating a weapons-testes trade-off. However, at high social densities, males that dropped a hindlimb did not grow larger testes, though testes were already large at this density. These results underscore the importance of the social context to resource allocation patterns within the individual.
Collapse
Affiliation(s)
- Christine W Miller
- Entomology & Nematology Department, University of Florida, Gainesville, FL, USA
| | - Paul N Joseph
- Entomology & Nematology Department, University of Florida, Gainesville, FL, USA
| | - Zachary Emberts
- Department of Biology, University of Florida, Gainesville, FL, USA
| |
Collapse
|
12
|
Pham HT, McNamara KB, Elgar MA. Age-dependent chemical signalling and its consequences for mate attraction in the gumleaf skeletonizer moth, Uraba lugens. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2020.12.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
13
|
Pham HT, McNamara KB, Elgar MA. Socially cued anticipatory adjustment of female signalling effort in a moth. Biol Lett 2020; 16:20200614. [PMID: 33259772 DOI: 10.1098/rsbl.2020.0614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Juvenile population density has profound effects on subsequent adult development, morphology and reproductive investment. Yet, little is known about how the juvenile social environment affects adult investment into chemical sexual signalling. Male gumleaf skeletonizer moths, Uraba lugens, facultatively increase investment into antennae (pheromone receiving structures) when reared at low juvenile population densities, but whether there is comparable adjustment by females into pheromone investment is not known. We investigate how juvenile population density influences the 'calling' (pheromone-releasing) behaviour of females and the attractiveness of their pheromones. Female U. lugens adjust their calling behaviour in response to socio-sexual cues: adult females reared in high juvenile population densities called earlier and for longer than those from low juvenile densities. Juvenile density also affected female pheromonal attractiveness: Y-maze olfactometer assays revealed that males prefer pheromones produced by females reared at high juvenile densities. This strategic investment in calling behaviour by females, based on juvenile cues that anticipate the future socio-sexual environment, likely reflects a response to avoid mating failure through competition with neighbouring signallers.
Collapse
Affiliation(s)
- Hieu T Pham
- School of BioSciences, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kathryn B McNamara
- School of BioSciences, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Mark A Elgar
- School of BioSciences, University of Melbourne, Melbourne, Victoria 3010, Australia
| |
Collapse
|
14
|
Integrative developmental ecology: a review of density-dependent effects on life-history traits and host-microbe interactions in non-social holometabolous insects. Evol Ecol 2020. [DOI: 10.1007/s10682-020-10073-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AbstractPopulation density modulates a wide range of eco-evolutionary processes including inter- and intra-specific competition, fitness and population dynamics. In holometabolous insects, the larval stage is particularly susceptible to density-dependent effects because the larva is the resource-acquiring stage. Larval density-dependent effects can modulate the expression of life-history traits not only in the larval and adult stages but also downstream for population dynamics and evolution. Better understanding the scope and generality of density-dependent effects on life-history traits of current and future generations can provide useful knowledge for both theory and experiments in developmental ecology. Here, we review the literature on larval density-dependent effects on fitness of non-social holometabolous insects. First, we provide a functional definition of density to navigate the terminology in the literature. We then classify the biological levels upon which larval density-dependent effects can be observed followed by a review of the literature produced over the past decades across major non-social holometabolous groups. Next, we argue that host-microbe interactions are yet an overlooked biological level susceptible to density-dependent effects and propose a conceptual model to explain how density-dependent effects on host-microbe interactions can modulate density-dependent fitness curves. In summary, this review provides an integrative framework of density-dependent effects across biological levels which can be used to guide future research in the field of ecology and evolution.
Collapse
|
15
|
Greenway EVG, Cirino LA, Wilner D, Somjee U, Anagnostou ME, Hepple RT, Miller CW. Extreme variation in testes size in an insect is linked to recent mating activity. J Evol Biol 2019; 33:142-150. [PMID: 31765505 DOI: 10.1111/jeb.13574] [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: 08/19/2019] [Revised: 11/08/2019] [Accepted: 11/14/2019] [Indexed: 12/23/2022]
Abstract
Ample sperm production is essential for successful male reproduction in many species. The amount of sperm a male can produce is typically constrained by the size of his testes, which can be energetically expensive to grow and maintain. Although the economics of ejaculate allocation has been the focus of much theoretical and empirical literature, relatively little attention has been paid to individual adult variation and plasticity at the source of sperm production, the testes themselves. We experimentally address this issue using the insect Narnia femorata Stål (Hemiptera: Coreidae). We established the metabolic cost of testicular tissue and then quantified variation in individual testes mass in response to multiple mate quality and quantity treatments. We uncovered extreme variation across individuals and considerable short-term effects of mating activity on testes dry mass. Importantly, the observed variation in testes mass was associated with notable fitness consequences; females paired with males with larger testes had greater hatching success. Overall, pairing with a female resulted in a 11% reduction in dry testes mass. Despite this apparent considerable mating investment, we found no evidence of strategic allocation to higher quality females or longer-term changes in testes mass. The dynamic nature of testes mass and its metabolic cost is vital to consider in the context of re-mating rates, polyandry benefits and general mating system dynamics both in this species and more broadly.
Collapse
Affiliation(s)
- E V Ginny Greenway
- Entomology and Nematology Department, University of Florida, Gainesville, Florida
| | - Lauren A Cirino
- Entomology and Nematology Department, University of Florida, Gainesville, Florida
| | - Daniela Wilner
- Entomology and Nematology Department, University of Florida, Gainesville, Florida
| | - Ummat Somjee
- Entomology and Nematology Department, University of Florida, Gainesville, Florida.,Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
| | | | - Russell T Hepple
- Department of Physical Therapy, University of Florida, Gainesville, Florida
| | - Christine W Miller
- Entomology and Nematology Department, University of Florida, Gainesville, Florida
| |
Collapse
|
16
|
Elgar MA, Zhang D, Wang Q, Wittwer B, Thi Pham H, Johnson TL, Freelance CB, Coquilleau M. Insect Antennal Morphology: The Evolution of Diverse Solutions to Odorant Perception. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2018; 91:457-469. [PMID: 30588211 PMCID: PMC6302626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chemical communication involves the production, transmission, and perception of odors. Most adult insects rely on chemical signals and cues to locate food resources, oviposition sites or reproductive partners and, consequently, numerous odors provide a vital source of information. Insects detect these odors with receptors mostly located on the antennae, and the diverse shapes and sizes of these antennae (and sensilla) are both astonishing and puzzling: what selective pressures are responsible for these different solutions to the same problem - to perceive signals and cues? This review describes the selection pressures derived from chemical communication that are responsible for shaping the diversity of insect antennal morphology. In particular, we highlight new technologies and techniques that offer exciting opportunities for addressing this surprisingly neglected and yet crucial component of chemical communication.
Collapse
Affiliation(s)
- Mark A. Elgar
- School of BioSciences, The University of Melbourne, Victoria, Australia,To whom all correspondence should be addressed: Mark A. Elgar, School of BioSciences, The University of Melbourne, Victoria 3010, Australia; FAX: +61 3 8344 7909;
| | - Dong Zhang
- School of Nature Conservation, Beijing Forestry University, Beijing, China
| | - Qike Wang
- School of BioSciences, The University of Melbourne, Victoria, Australia
| | | | - Hieu Thi Pham
- School of BioSciences, The University of Melbourne, Victoria, Australia
| | - Tamara L. Johnson
- School of BioSciences, The University of Melbourne, Victoria, Australia
| | | | | |
Collapse
|
17
|
Johnson TL, Symonds MRE, Elgar MA. Anticipatory flexibility: larval population density in moths determines male investment in antennae, wings and testes. Proc Biol Sci 2017; 284:20172087. [PMID: 29118139 PMCID: PMC5698656 DOI: 10.1098/rspb.2017.2087] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/12/2017] [Indexed: 11/12/2022] Open
Abstract
Developmental plasticity provides individuals with a distinct advantage when the reproductive environment changes dramatically. Variation in population density, in particular, can have profound effects on male reproductive success. Females may be easier to locate in dense populations, but there may be a greater risk of sperm competition. Thus, males should invest in traits that enhance fertilization success over traits that enhance mate location. Conversely, males in less dense populations should invest more in structures that will facilitate mate location. In Lepidoptera, this may result in the development of larger antennae to increase the likelihood of detecting female sex pheromones, and larger wings to fly more efficiently. We explored the effects of larval density on adult morphology in the gum-leaf skeletonizer moth, Uraba lugens, by manipulating both the number of larvae and the size of the rearing container. This experimental arrangement allowed us to reveal the cues used by larvae to assess whether absolute number or density influences adult responses. Male investment in testes size depended on the number of individuals, while male investment in wings and antennae depended upon larval density. By contrast, the size of female antennae and wings were influenced by an interaction of larval number and container size. This study demonstrates that male larvae are sensitive to cues that may reveal adult population density, and adjust investment in traits associated with fertilization success and mate detection accordingly.
Collapse
Affiliation(s)
- Tamara L Johnson
- School of Biosciences, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Matthew R E Symonds
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia
| | - Mark A Elgar
- School of Biosciences, University of Melbourne, Melbourne, Victoria 3010, Australia
| |
Collapse
|