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Acal DA, Sulikowska-Drozd A, Jaskuła R. Filling the gaps in ecology of tropical tiger beetles (Coleoptera: Cicindelidae): first quantitative data of sexual dimorphism in semi-arboreal Therates from the Philippine biodiversity hotspot. PeerJ 2024; 12:e16956. [PMID: 38495761 PMCID: PMC10944163 DOI: 10.7717/peerj.16956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/25/2024] [Indexed: 03/19/2024] Open
Abstract
Background Sexual dimorphism, driven by sexual selection, leads to varied morphological distinctions in male and female insects, providing insights into selection pressures across species. However, research on the morphometric variability within specific taxa of tiger beetles (Coleoptera: Cicindelidae), particularly arboreal and semi-arboreal species, remains very limited. Methods We investigate sexual dimorphism in six semi-arboreal Therates tiger beetle taxa from the Philippines, focusing on morphological traits. We employed morphometric measurements and multivariate analyses to reveal patterns of sexual dimorphism between sexes within the taxa. Results Our results indicate significant sexual dimorphism in elytra width, with females consistently displaying broader elytra, potentially enhancing fecundity. Notable sexual size dimorphism was observed in Therates fulvipennis bidentatus and T. coracinus coracinus, suggesting heightened sexual selection pressures on male body size. Ecological factors, mating behavior, and female mate choice might contribute to the observed morphological variation. These findings emphasize the need for further studies to comprehend mating dynamics, mate choice, and ecological influences on morphological variations in semi-arboreal and arboreal tiger beetles.
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Affiliation(s)
- Dale Ann Acal
- Department of Invertebrate Zoology and Hydrobiology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Anna Sulikowska-Drozd
- Department of Invertebrate Zoology and Hydrobiology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Radomir Jaskuła
- Department of Invertebrate Zoology and Hydrobiology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
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Martens BM, Martin OY, Janicke T, Winkler L. No fitness effects of same-sex copulations in male red flour beetles. Ecol Evol 2024; 14:e11027. [PMID: 38505178 PMCID: PMC10949009 DOI: 10.1002/ece3.11027] [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: 12/04/2023] [Revised: 01/22/2024] [Accepted: 02/01/2024] [Indexed: 03/21/2024] Open
Abstract
Same-sex sexual behavior occurs in diverse animal taxa, yet its evolutionary maintenance is poorly understood as such behavior seems to be costly and does not directly increase reproductive success. We used male Tribolium castaneum beetles, which frequently engage in same-sex copulations, to test if same-sex sexual behavior influences future male mating behavior and reproductive success of males. Furthermore, we tested whether same-sex sexual behavior has benefits via indirect sperm translocation. We conducted a series of mating trials demonstrating that males exposed to same-sex behavior did not sire less offspring compared to control males that did not engage in same-sex behavior. This suggests that same-sex copulations did not lead to fitness costs in subsequent mating interactions. In addition, we found no evidence that indirect sperm translocation via an intermediate male occurs in T. castaneum. Taken together, these results imply that same-sex sexual behavior in males is associated with no costs in terms of lower mating rate and reduced siring success and does not seem to entail benefits. Moreover, our data conform to the hypothesis that sexual indiscrimination is prevalent in this species, which may explain the relatively high frequency of same-sex sexual behavior in T. castaneum.
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Affiliation(s)
| | - Oliver Y. Martin
- Department of Biology & Institute of Integrative Biology (IBZ)ETH ZürichZurichSwitzerland
| | - Tim Janicke
- Applied ZoologyTU DresdenDresdenGermany
- Centre d'Écologie Fonctionnelle et Évolutive, UMR 5175, CNRSUniversité de Montpellier, École Pratique des Hautes ÉtudesMontpellier Cedex 05France
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Carleial R, Pizzari T, Richardson DS, McDonald GC. Disentangling the causes of temporal variation in the opportunity for sexual selection. Nat Commun 2023; 14:1006. [PMID: 36813810 PMCID: PMC9947164 DOI: 10.1038/s41467-023-36536-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
In principle, temporal fluctuations in the potential for sexual selection can be estimated as changes in intrasexual variance in reproductive success (i.e. the opportunity for selection). However, we know little about how opportunity measures vary over time, and the extent to which such dynamics are affected by stochasticity. We use published mating data from multiple species to investigate temporal variation in the opportunity for sexual selection. First, we show that the opportunity for precopulatory sexual selection typically declines over successive days in both sexes and shorter sampling periods lead to substantial overestimates. Second, by utilising randomised null models, we also find that these dynamics are largely explained by an accumulation of random matings, but that intrasexual competition may slow temporal declines. Third, using data from a red junglefowl (Gallus gallus) population, we show that declines in precopulatory measures over a breeding period were mirrored by declines in the opportunity for both postcopulatory and total sexual selection. Collectively, we show that variance-based metrics of selection change rapidly, are highly sensitive to sampling durations, and likely lead to substantial misinterpretation if used as indicators of sexual selection. However, simulations can begin to disentangle stochastic variation from biological mechanisms.
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Affiliation(s)
- Rômulo Carleial
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, OX1 3SZ, UK.
- Science Directorate, Royal Botanic Gardens, Kew, Richmond, TW9 3AE, UK.
| | - Tommaso Pizzari
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, OX1 3SZ, UK
| | | | - Grant C McDonald
- Department of Ecology, University of Veterinary Medicine Budapest, Budapest, 1077, Hungary.
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Competitive Sperm-Marked Beetles for Monitoring Approaches in Genetic Biocontrol and Studies in Reproductive Biology. Int J Mol Sci 2022; 23:ijms232012594. [DOI: 10.3390/ijms232012594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/03/2022] [Accepted: 10/12/2022] [Indexed: 11/16/2022] Open
Abstract
Sperm marking provides a key tool for reproductive biology studies, but it also represents a valuable monitoring tool for genetic pest control strategies such as the sterile insect technique. Sperm-marked lines can be generated by introducing transgenes that mediate the expression of fluorescent proteins during spermatogenesis. The homozygous lines established by transgenesis approaches are going through a genetic bottleneck that can lead to reduced fitness. Transgenic SIT approaches have mostly focused on Dipteran and Lepidopteran pests so far. With this study, we provide sperm-marked lines for the Coleopteran pest model organism, the red flour beetle Tribolium castaneum, based on the β2-tubulin promoter/enhancer driving red (DsRed) or green (EGFP) fluorescence. The obtained lines are reasonably competitive and were thus used for our studies on reproductive biology, confirming the phenomenon of ‘last-male sperm precedence’ and that the spermathecae are deployed for long-term sperm storage, enabling the use of sperm from first mating events even after secondary mating events for a long period of time. The homozygosity and competitiveness of the lines will enable future studies to analyze the controlled process of sperm movement into the long-term storage organ as part of a post-mating cryptic female choice mechanism of this extremely promiscuous species.
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Female remating decisions and mate choice benefits in the beetle Gnatocerus cornutus. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03161-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Reuland C, Culbert BM, Devigili A, Kahrl AF, Fitzpatrick JL. Contrasting female mate preferences for red coloration in a fish. Curr Zool 2020; 66:425-433. [PMID: 32617091 PMCID: PMC7319460 DOI: 10.1093/cz/zoz052] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/12/2019] [Indexed: 11/28/2022] Open
Abstract
Understanding how animals select their mates requires knowing the factors that shape mate preferences. Recent theoretical and empirical considerations suggest that female mating status can influence the degree to which a female engages in mate choice, with virgin females predicted to be less choosy than mated females. In this study, we investigated mate choice in both virgin and mated females in the pygmy halfbeak Dermogenys collettei. Halfbeaks are small, live-bearing, internally fertilizing freshwater fish that live in mixed-sex groups where females have ample opportunity to engage in mate choice. Using a dichotomous choice assay, we quantified and contrasted in virgin and mated females mate preferences for differences in male body size, beak size, and area of yellow and red coloration. We also examined how mating status influenced the amount of time a female associated with the first male encountered and the relative amount of time a female associated with each male. We demonstrate that mate preferences of female halfbeaks are driven primarily by the size of red coloration present on males. Females showed contrasting preferences based on mating status, with virgin females preferentially associating with drab males whereas mated females preferentially associate with males possessing large areas of red. Contrary to expectations, female mating status did not influence how females associate with the first males encountered or how females biased their association time among males. Although the precise drivers of these effects need further studying, our finding highlights a possible explanation for how variation in male ornamentation can be maintained.
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Affiliation(s)
- Charel Reuland
- Department of Zoology, Stockholm University, Stockholm, SE-10691, Sweden
| | - Brett M Culbert
- Department of Integrative Biology, University of Guelph, Guelph, N1G 2W1, Canada
| | | | - Ariel F Kahrl
- Department of Zoology, Stockholm University, Stockholm, SE-10691, Sweden
| | - John L Fitzpatrick
- Department of Zoology, Stockholm University, Stockholm, SE-10691, Sweden
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Wu Q, Wen L, Chen J, Li D, Jiao X. Experimental evidence for the genetic benefits of female mate choice in the monandrous wolf spider Pardosa astrigera. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Russell AL, Buchmann SL, Sabino WDO, Papaj DR. Brawls Bring Buzz: Male Size Influences Competition and Courtship in Diadasia rinconis (Hymenoptera: Apidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2018; 18:5084941. [PMID: 30165489 PMCID: PMC6113682 DOI: 10.1093/jisesa/iey083] [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: 06/07/2018] [Indexed: 06/08/2023]
Abstract
Sexual selection on male body size in species with a female-biased sexual size dimorphism is common yet often poorly understood. In particular, in the majority of bee species, the relative contribution of intrasexual competition and female choice to patterns of male body size is unknown. In this field study, we examined two possible components of male mating success with respect to body size in the solitary bee Diadasia rinconis Cockerell (Hymenoptera: Apidae): 1) ability to procure a mate and 2) the duration of copulation. We found that larger males were better able to procure mates and copulated for shorter periods of time. Although consistent with sperm competition theory, differences in copulation duration were slight; possibly, the shorter copulations of larger males instead reflect in copulo female choice. Consistent with this notion, males engaged in complex courtship while mounted, characterized for the first time in any bee in such detail via audio recordings and high-speed, high-definition video. The number of pulses in male courtship behavior was also positively associated with copulation duration and may have stimulated females to continue copulating, thereby potentially allowing smaller males to transfer a full ejaculate. Females were shown to be potentially polyandrous and although we did not observe precopulatory rejection in the field, captive females frequently rejected copulation attempts by captive males. Our work indicates that intrasexual competition selects for increased body size in a solitary bee.
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Affiliation(s)
- Avery L Russell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA
- Department of Entomology, University of Arizona, Tucson, AZ
- Graduate Interdisciplinary Program in Entomology and Insect Science, University of Arizona, Tucson, AZ
| | - Stephen L Buchmann
- Department of Entomology, University of Arizona, Tucson, AZ
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
| | - William de O Sabino
- Museu Paraense Emílio Goeldi, Coordenação de Zoologia, Avenida Perimetral, Belém, PA, Brazil
| | - Daniel R Papaj
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
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Khan I, Prakash A, Issar S, Umarani M, Sasidharan R, Masagalli JN, Lama P, Venkatesan R, Agashe D. Female Density-Dependent Chemical Warfare Underlies Fitness Effects of Group Sex Ratio in Flour Beetles. Am Nat 2018. [DOI: 10.1086/695806] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Evans JP, Garcia-Gonzalez F. The total opportunity for sexual selection and the integration of pre- and post-mating episodes of sexual selection in a complex world. J Evol Biol 2016; 29:2338-2361. [PMID: 27520979 DOI: 10.1111/jeb.12960] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 08/05/2016] [Accepted: 08/05/2016] [Indexed: 12/30/2022]
Abstract
It is well known that sexual selection can target reproductive traits during successive pre- and post-mating episodes of selection. A key focus of recent studies has been to understand and quantify how these episodes of sexual selection interact to determine overall variance in reproductive success. In this article, we review empirical developments in this field but also highlight the considerable variability in patterns of pre- and post-mating sexual selection, attributable to variation in patterns of resource acquisition and allocation, ecological and social factors, genotype-by-environment interaction and possible methodological factors that might obscure such patterns. Our aim is to highlight how (co)variances in pre- and post-mating sexually selected traits can be sensitive to changes in a range of ecological and environmental variables. We argue that failure to capture this variation when quantifying the opportunity for sexual selection may lead to erroneous conclusions about the strength, direction or form of sexual selection operating on pre- and post-mating traits. Overall, we advocate for approaches that combine measures of pre- and post-mating selection across contrasting environmental or ecological gradients to better understand the dynamics of sexual selection in polyandrous species. We also discuss some directions for future research in this area.
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Affiliation(s)
- J P Evans
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, WA, Australia
| | - F Garcia-Gonzalez
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, WA, Australia.,Doñana Biological Station, Spanish Research Council CSIC, Sevilla, Spain
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Wexler Y, Subach A, Pruitt JN, Scharf I. Behavioral repeatability of flour beetles before and after metamorphosis and throughout aging. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2098-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Sbilordo SH, Martin OY. Pre- and postcopulatory sexual selection act in concert to determine male reproductive success inTribolium castaneum. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12262] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Sonja H. Sbilordo
- ETH Zürich; Institute of Integrative Biology (IBZ); D-USYS; Universitätsstrasse 16 8092 Zürich Switzerland
| | - Oliver Y. Martin
- ETH Zürich; Institute of Integrative Biology (IBZ); D-USYS; Universitätsstrasse 16 8092 Zürich Switzerland
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Ming QL, Cheng C. Influence of nutrition on male development and reproduction in Tribolium castaneum. JOURNAL OF ECONOMIC ENTOMOLOGY 2012; 105:1471-1476. [PMID: 22928331 DOI: 10.1603/ec12057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Tribolium beetles have evolved over several thousand years to colonize and exploit various food products that vary widely in their nutritional quality. Here Tribolium castaneum was used as a model organism to explore the effect of nutritional quality on male development and reproduction. The results showed, when tested across different qualities of nutritional diets, Tribolium males developed faster and their body size was larger on a high-quality diet, and there were significant correlations between male developmental traits. However, Tribolium males fed different nutritional diets did not show significant variation in olfactory attractiveness, mating rate, insemination rate, sperm defense (P1), sperm offense (P2), and reproductive success within a population context (RSPC). Moreover, there was no significant correlation of male reproductive performances except RSPC with developmental traits, and except for P2 and RSPC, no significant correlations between male reproductive performances. Therefore, although male developmental performance was significantly influenced by diet quality, reproductive performance was not. We discussed these findings and their sexual selection implications in light of its habitat.
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Affiliation(s)
- Qing-Lei Ming
- Department of Biology, Tufts University, 163 Packard Ave., Medford, MA 02155, USA.
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LEWIS SM, TIGREROS N, FEDINA T, MING QL. Genetic and nutritional effects on male traits and reproductive performance in Tribolium flour beetles. J Evol Biol 2012; 25:438-51. [DOI: 10.1111/j.1420-9101.2011.02408.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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South A, Sirot LK, Lewis SM. Identification of predicted seminal fluid proteins in Tribolium castaneum. INSECT MOLECULAR BIOLOGY 2011; 20:447-456. [PMID: 21689183 DOI: 10.1111/j.1365-2583.2011.01083.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In several insect species, seminal fluid proteins (SFPs) have been demonstrated to be key regulators of male and female fitness through their ability to alter female physiology and behaviour. Tribolium castaneum is an economically important pest species and a model system for sexual selection research, but little is known about SFPs in this insect. To create a foundation for the study of T. castaneum SFPs, we used mass spectrometry to identify putative SFPs by comparing proteins detected in the male reproductive glands with those found in the reproductive tracts of virgin and mated females. Fourteen putative SFPs, thirteen with male biased expression, were identified through this approach. We also used reverse transcription PCR (RT-PCR) to examine expression levels across different tissue types. We found strongly male-biased expression in 13 genes, nine of which were expressed only in male accessory gland tissue. This represents the first proteomic-based method of identifying putative SFPs in any coleopteran species, and is the first study in this species to identify putative SFPs that are likely transferred to the female. This work could lead to functional analyses of the role of SFPs in sexual selection, sexual conflict and potential control of a pest species.
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Affiliation(s)
- A South
- Department of Biology, Tufts University, Medford, MA 02155, USA.
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Sato A, Shimoichi A, Karino K. Copulation Type Affects Parturition in the Guppy. Zoolog Sci 2011; 28:98-104. [DOI: 10.2108/zsj.28.98] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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RASHED ARASH, POLAK MICHAL. Does male secondary sexual trait size reveal fertilization efficiency in Australian Drosophila bipectinata Duda (Diptera: Drosophilidae)? Biol J Linn Soc Lond 2009. [DOI: 10.1111/j.1095-8312.2009.01268.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Welke K, Schneider JM. Inbreeding avoidance through cryptic female choice in the cannibalistic orb-web spider Argiope lobata. Behav Ecol 2009. [DOI: 10.1093/beheco/arp097] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tregenza T, Attia F, Bushaiba SS. Repeatability and heritability of sperm competition outcomes in males and females of Tribolium castaneum. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0716-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Xu J, Wang Q. Male moths undertake both pre- and in-copulation mate choice based on female age and weight. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0713-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Fedina TY, Lewis SM. An integrative view of sexual selection in Tribolium flour beetles. Biol Rev Camb Philos Soc 2008; 83:151-71. [PMID: 18429767 DOI: 10.1111/j.1469-185x.2008.00037.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sexual selection is a major force driving the evolution of diverse reproductive traits. This evolutionary process is based on individual reproductive advantages that arise either through intrasexual competition or through intersexual choice and conflict. While classical studies of sexual selection focused mainly on differences in male mating success, more recent work has focused on the differences in paternity share that may arise through sperm competition or cryptic female choice whenever females mate with multiple males. Thus, an integrative view of sexual selection needs to encompass processes that occur not only before copulation (pre-mating), but also during copulation (peri-mating), as well as after copulation (post-mating), all of which can generate differences in reproductive success. By encompassing mechanisms of sexual selection across all of these sequential reproductive stages this review takes an integrative approach to sexual selection in Tribolium flour beetles (Coleoptera: Tenebrionidae), a particularly well-studied and economically important model organism. Tribolium flour beetles colonize patchily distributed grain stores, and juvenile and adult stages share the same food resources. Adults are highly promiscuous and female reproduction is distributed across an adult lifespan lasting approximately 1 year. While Tribolium males produce an aggregation pheromone that attracts both sexes, there appears to be little pre-mating discrimination among potential mates by either sex. However, recent work has revealed several peri-mating and post-mating mechanisms that determine how offspring paternity is apportioned among a female's mates. During mating, Tribolium females reject spermatophore transfer and limit sperm numbers transferred by males with low phenotypic quality. Although there is some conflicting evidence, male copulatory leg-rubbing appears to be associated with overcoming female resistance to insemination and does not influence a male's subsequent paternity share. Evidence suggests that Tribolium beetles have several possible post-mating mechanisms that they may use to bias paternity. Male sperm precedence has been extensively studied in Tribolium spp. and the related Tenebrio molitor, and several factors influencing male paternity share among a female's progeny have been identified. These include oviposition time, inter-mating interval, male strain/genotype, the mating regimen of a male's mother, male starvation, and tapeworm infection. Females exert muscular control over sperm storage, although there is no evidence to date that females use this to differentiate among mates. Females could also influence offspring paternity by re-mating with additional males, and T. castaneum females more readily accept spermatophores when they are re-mating with more attractive males. Additional work is needed to examine the possible roles played by both male and female accessory gland products in determining male paternity share. Sexual selection during pre-mating episodes may be reinforced or counteracted by peri- and post-copulatory selection, and antagonistic coevolution between the sexes may be played out across reproductive stages. In Tribolium, males' olfactory attractiveness is positively correlated with both insemination success and paternity share, suggesting consistent selection across different reproductive stages. Similar studies across sequential reproductive stages are needed in other taxa to provide a more integrative view of sexual selection.
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