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Physiology & Behavior Oct 2021Reproduction is a key determinant of organismal fitness, but organisms almost always face the threat of parasite infection. Thus, potential trade-offs between mating and...
Reproduction is a key determinant of organismal fitness, but organisms almost always face the threat of parasite infection. Thus, potential trade-offs between mating and parasite resistance may have substantial impacts on the ecology and evolution of host species. Although trade-offs between microbial resistance and mating in arthropods are well-documented, there is a paucity of evidence that mating compromises host resistance to the ubiquitous threat posed by ectoparasites. Despite the centrality of reproduction to host fitness and the widespread risk of parasites, there is a dearth of experiments showing a trade-off between mating/reproduction and anti-parasite behaviours. In this study, we test if mating increases the susceptibility of female flies to mite infection. We also investigated a potential underlying mechanism for the trade-off: that mating reduces overall endurance and hence anti-parasitic defenses among female flies. We experimentally mated female Drosophila nigrospiracula, with or without a chance to recover from male harassment, and challenged them with a natural ectoparasite, the mite Macrocheles subbadius. Mated females, regardless of time for recovery from male harassment, acquired more infections than unmated females. Furthermore, mated females had lower endurance in negative geotaxis assays, suggesting the increased susceptibility is due to reduced endurance. Our research shows a trade-off between reproduction and parasite resistance in a host-macroparasite system and suggests that trade-off theory is a fruitful direction for understanding these associations.
Topics: Animals; Drosophila; Female; Male; Mites; Parasites; Reproduction
PubMed: 34229032
DOI: 10.1016/j.physbeh.2021.113524 -
PLoS Neglected Tropical Diseases Sep 2021Aedes aegypti mosquitoes are globally distributed vectors of viruses that impact the health of hundreds of millions of people annually. Mating and blood feeding...
BACKGROUND
Aedes aegypti mosquitoes are globally distributed vectors of viruses that impact the health of hundreds of millions of people annually. Mating and blood feeding represent fundamental aspects of mosquito life history that carry important implications for vectorial capacity and for control strategies. Females transmit pathogens to vertebrate hosts and obtain essential nutrients for eggs during blood feeding. Further, because host-seeking Ae. aegypti females mate with males swarming near hosts, biological crosstalk between these behaviors could be important. Although mating influences nutritional intake in other insects, prior studies examining mating effects on mosquito blood feeding have yielded conflicting results.
METHODOLOGY/PRINCIPAL FINDINGS
To resolve these discrepancies, we examined blood-feeding physiology and behavior in virgin and mated females and in virgins injected with male accessory gland extracts (MAG), which induce post-mating changes in female behavior. We controlled adult nutritional status prior to blood feeding by using water- and sugar-fed controls. Our data show that neither mating nor injection with MAG affect Ae. aegypti blood intake, digestion, or feeding avidity for an initial blood meal. However, sugar feeding, a common supplement in laboratory settings but relatively rare in nature, significantly affected all aspects of feeding and may have contributed to conflicting results among previous studies. Further, mating, MAG injection, and sugar intake induced declines in subsequent feedings after an initial blood meal, correlating with egg production and laying. Taking our evaluation to the field, virgin and mated mosquitoes collected in Colombia were equally likely to contain blood at the time of collection.
CONCLUSIONS/SIGNIFICANCE
Mating, MAG, and sugar feeding impact a mosquito's estimated ability to transmit pathogens through both direct and indirect effects on multiple aspects of mosquito biology. Our results highlight the need to consider natural mosquito ecology, including diet, when assessing their physiology and behavior in the laboratory.
Topics: Aedes; Animals; Arboviruses; Blood; Colombia; Disease Vectors; Feeding Behavior; Female; Humans; Male; Mosquito Vectors; Reproduction; Sexual Behavior, Animal; Sugars
PubMed: 34591860
DOI: 10.1371/journal.pntd.0009815 -
Journal of Thermal Biology Dec 2022Temperature influences all aspects of insect physiology and behaviour, including reproduction. Adverse temperatures can decrease mating success and sperm transfer,...
Temperature influences all aspects of insect physiology and behaviour, including reproduction. Adverse temperatures can decrease mating success and sperm transfer, leading to increased sex ratio (more males) in populations of haplodiploid organisms. We tested the effect of five temperatures on the reproduction of the egg parasitoid Anaphes listronoti. Temperatures above and below 24.5°C decreased mating success by 30%-80%. Mating failures can arise from lack of encounters between sexes, absence of courting by the male, or the female refusing to mate. Both courtship and copulation duration decreased with increasing temperature. For mated females, there was no effect of mating temperature on offspring number and sex ratio. However, the increased number of virgin females at adverse temperatures did modify the simulated population sex ratio of the next generation, which increased from 0.2 at 24.5°C to 0.4, 0.5, 0.4 and 0.8 at 15.7°C, 20°C and 30°C and 35°C, respectively. The effect of temperature on courtship and copulation success of A. listronoti could lead to a decrease of the number of females in the population.
Topics: Animals; Male; Female; Temperature; Semen; Reproduction; Sex Ratio; Spermatozoa
PubMed: 36462844
DOI: 10.1016/j.jtherbio.2022.103382 -
Nature Oct 2019Sexual imprinting-a phenomenon in which offspring learn parental traits and later use them as a model for their own mate preferences-can generate reproductive barriers...
Sexual imprinting-a phenomenon in which offspring learn parental traits and later use them as a model for their own mate preferences-can generate reproductive barriers between species. When the target of imprinting is a mating trait that differs among young lineages, imprinted preferences may contribute to behavioural isolation and facilitate speciation. However, in most models of speciation by sexual selection, divergent natural selection is also required; the latter acts to generate and maintain variation in the sexually selected trait or traits, and in the mating preferences that act upon them. Here we demonstrate that imprinting, in addition to mediating female mate preferences, can shape biases in male-male aggression. These biases can act similarly to natural selection to maintain variation in traits and mate preferences, which facilitates reproductive isolation driven entirely by sexual selection. Using a cross-fostering study, we show that both male and female strawberry poison frogs (Oophaga pumilio) imprint on coloration, which is a mating trait that has diverged recently and rapidly in this species. Cross-fostered females prefer to court mates of the same colour as their foster mother, and cross-fostered males are more aggressive towards rivals that share the colour of their foster mother. We also use a simple population-genetics model to demonstrate that when both male aggression biases and female mate preferences are formed through parental imprinting, sexual selection alone can (1) stabilize a sympatric polymorphism and (2) strengthen the trait-preference association that leads to behavioural reproductive isolation. Our study provides evidence of imprinting in an amphibian and suggests that this rarely considered combination of rival and sexual imprinting can reduce gene flow between individuals that bear divergent mating traits, which sets the stage for speciation by sexual selection.
Topics: Aggression; Animals; Anura; Costa Rica; Female; Gene Flow; Genetic Speciation; Genomic Imprinting; Male; Maternal Inheritance; Mating Preference, Animal; Nicaragua; Panama; Paternal Inheritance; Polymorphism, Genetic; Skin Pigmentation
PubMed: 31578486
DOI: 10.1038/s41586-019-1599-z -
Molecular Ecology Jan 2020Assortative mating is a deviation from random mating based on phenotypic similarity. As it is much better studied in animals than in plants, we investigate for trees...
Assortative mating is a deviation from random mating based on phenotypic similarity. As it is much better studied in animals than in plants, we investigate for trees whether kinship of realized mating pairs deviates from what is expected from the set of potential mates and use this information to infer mating biases that may result from kin recognition and/or assortative mating. Our analysis covers 20 species of trees for which microsatellite data is available for adult populations (potential mates) as well as seed arrays. We test whether mean relatedness of observed mating pairs deviates from null expectations that only take pollen dispersal distances into account (estimated from the same data set). This allows the identification of elevated as well as reduced kinship among realized mating pairs, indicative of positive and negative assortative mating, respectively. The test is also able to distinguish elevated biparental inbreeding that occurs solely as a result of related pairs growing closer to each other from further assortativeness. Assortative mating in trees appears potentially common but not ubiquitous: nine data sets show mating bias with elevated inbreeding, nine do not deviate significantly from the null expectation, and two show mating bias with reduced inbreeding. While our data sets lack direct information on phenology, our investigation of the phenological literature for each species identifies flowering phenology as a potential driver of positive assortative mating (leading to elevated inbreeding) in trees. Since active kin recognition provides an alternative hypothesis for these patterns, we encourage further investigations on the processes and traits that influence mating patterns in trees.
Topics: Ecology; Genotype; Inbreeding; Microsatellite Repeats; Phenotype; Pollen; Reproduction; Trees
PubMed: 31755136
DOI: 10.1111/mec.15312 -
The Journal of Animal Ecology May 2021Despite increasing evidence of the importance of repeatable among-individual differences in behaviour (animal personality) in ecology and evolution, little remains known...
Despite increasing evidence of the importance of repeatable among-individual differences in behaviour (animal personality) in ecology and evolution, little remains known about the role of animal personalities in sexual selection. Here, we present an investigation of the hypothesis that the personalities of individuals and their sexual partners play a role in different episodes of sexual selection, and the extent to which these effects are modulated by the social environment. We first examined how two repeatable behaviours-exploration and boldness-are associated with pre- and postcopulatory sexual selection in male red junglefowl Gallus gallus, using replicate groups across three experimental sex ratio treatments. We further explored how the social environment modulates relationships between male personality and mating performance, and whether mating is assortative or disassortative with respect to exploration or boldness. Finally, we examined behavioural mechanisms linking personality with mating performance. Across all sex ratios, the fastest and slowest exploring males courted females proportionally less, and faster exploring males associated with females more and received more sexual solicitations. In female-biased groups, the fastest and slowest exploring males experienced the highest mating success and lowest sperm competition intensity. Faster exploring males also obtained more mates in female-biased groups when their competitors were, on average, slower exploring, and the proportion of matings obtained by fast-exploring males decreased with the proportion of fast-exploring males in a group, consistent with negative frequency-dependent sexual selection. While boldness did not predict mating performance, there was a tendency for individuals to mate disassortatively with respect to boldness. Collectively, our results suggest that male exploration can play a role in sexual selection, and that sexual selection on personality is complex and contingent on the social environment.
Topics: Animals; Chickens; Female; Male; Mating Preference, Animal; Personality; Sexual Behavior, Animal; Sexual Selection
PubMed: 33630314
DOI: 10.1111/1365-2656.13454 -
Evolution; International Journal of... Aug 2021Dietary restriction during development can affect adult body size and condition. In many species, larger (high-condition) males gain higher mating success through...
Dietary restriction during development can affect adult body size and condition. In many species, larger (high-condition) males gain higher mating success through male-male competition and female choice, and female condition can affect the extent of both female mate choice and male investment in courtship or ejaculates. However, few studies have examined the joint effects and interplay of male and female condition during both the pre- and the postcopulatory phases of sexual selection. We therefore manipulated the larval diet of male and female Drosophila melanogaster to study how body size variation in both sexes biases competitive outcomes at different reproductive stages, from mating to paternity. We did not find a difference in mate preference or mating latency between females of different conditions, nor any interaction between male and female conditions. However, large males were more successful in gaining matings, but only when in direct competition, whereas mating latencies were shorter for low-condition males in noncompetitive settings. Small males also transferred more sperm to nonvirgin females, displaced a larger proportion of resident sperm, and achieved higher paternity shares per mating than large males. In agreement with existing theory, we suggest that small males might partially compensate for their low mating success by strategically investing in larger sperm numbers and potentially other, unmeasured ejaculate traits, when they do have a mating opportunity.
Topics: Animals; Courtship; Drosophila melanogaster; Female; Fertilization; Male; Reproduction; Sexual Behavior, Animal; Spermatozoa
PubMed: 33834478
DOI: 10.1111/evo.14228 -
Adaptive Human Behavior and Physiology 2021One of the factors that sexual disgust should be calibrated to is the size of the mating pool. This study tested this hypothesis by examining whether perceptions of mate...
OBJECTIVE
One of the factors that sexual disgust should be calibrated to is the size of the mating pool. This study tested this hypothesis by examining whether perceptions of mate availability explain variance in levels of sexual disgust towards potential mates.
METHODS
Participants ( = 853; 373 women) rated how sexually disgusting they found 60 potential mates that have previously been rated on attractiveness by a separate group of raters. We also measured participants' perceptions of mate availability in their local environment, self-perceived attractiveness and mate value, and relevant control variables.
RESULTS
Multilevel models revealed a negative association between sexual disgust towards potential mates and perceived mate availability-the opposite of what we predicted. We found support for our prediction that women had higher levels of sexual disgust than men, but only after addressing the confounding sex difference in target attractiveness. We also found the predicted negative association between target attractiveness and sexual disgust. Finally, as predicted, sexual disgust levels were more strongly related to potential mates' attractiveness in individuals who perceived there to be many available mates in their local environment.
CONCLUSIONS
These findings generally bolster functional accounts of sexual disgust while highlighting the need for more evidence to ascertain the role of mate availability in the calibration of sexual disgust. Specifically, future research should examine the extent to which disgust levels may truncate mental representations of the mating pool instead of being calibrated by them.
PubMed: 34002123
DOI: 10.1007/s40750-021-00168-2 -
Frontiers in Plant Science 2022Bird pollination in Asia is regarded as an uncommon phenomenon and, therefore, only a few investigations on mating pattern and paternity in fruits of Asian...
Bird pollination in Asia is regarded as an uncommon phenomenon and, therefore, only a few investigations on mating pattern and paternity in fruits of Asian bird-pollinated plants have been conducted. Here, we examined spatial genetic structure, pollen dispersal, and multiple paternity in a natural population of () (Malvaceae) in Hainan Island, South China, using simple sequence repeat (SSR) markers. A low genetic diversity ( = 0.351 ± 0.0341 and 0.389 ± 0.043, respectively, for adults and offspring) and bottleneck effects were observed. Genetic kinship was significant within 400 m or in 1,800-3,800 m. Both the mating pattern and paternity analysis confirmed obligate xenogamy and a low multiple paternity in . There was a strongly negative relationship between the frequency of matings and the distance between mating pairs. The average pollen dispersal distance was 202.89 ± 41.01 m (mean ± SE) and the farthest distance of > 1 km was recorded. Realized mating events showed an extremely leptokurtic distribution within 1,200 m, suggesting that the pollen dispersal distance was consistent with the optimal foraging theory of generalist birds such as spp. and spp. Paternity per tree ranged from two to six and the average effective number of pollen donors per maternal plant was 3.773, suggesting a low level of paternity diversity as compared to other bird-pollinated plants. We concluded that optimal foraging behavior by generalist birds could explain the leptokurtic pollen dispersal distribution and predominantly near-neighbor matings in . The limited pollen dispersal distance and low multiple paternity were consistent with low fruit setting rate (3.27 ± 0.93%) in this self-incompatible tree, which was caused mainly by the restricted flight distance of birds and human disturbances. Low genetic diversity and significant spatial genetic structure might have largely resulted from logging and human collection of fruits.
PubMed: 35283871
DOI: 10.3389/fpls.2022.806217 -
Nature Ecology & Evolution Jul 2021Animals are usually expected to avoid mating with relatives (kin avoidance) as incestuous mating can lead to the expression of inbreeding depression. Yet, theoretical... (Meta-Analysis)
Meta-Analysis
Animals are usually expected to avoid mating with relatives (kin avoidance) as incestuous mating can lead to the expression of inbreeding depression. Yet, theoretical models predict that unbiased mating with regards to kinship should be common, and that under some conditions, the inclusive fitness benefits associated with inbreeding can even lead to a preference for mating with kin. This mismatch between empirical and theoretical expectations generates uncertainty as to the prevalence of inbreeding avoidance in animals. Here, we synthesized 677 effect sizes from 139 experimental studies of mate choice for kin versus non-kin in diploid animals, representing 40 years of research, using a meta-analytical approach. Our meta-analysis revealed little support for the widely held view that animals avoid mating with kin, despite clear evidence of publication bias. Instead, unbiased mating with regards to kinship appears widespread across animals and experimental conditions. The significance of a variety of moderators was explored using meta-regressions, revealing that the degree of relatedness and prior experience with kin explained some variation in the effect sizes. Yet, we found no difference in kin avoidance between males and females, choice and no-choice experiments, mated and virgin animals or between humans and animals. Our findings highlight the need to rethink the widely held view that inbreeding avoidance is a given in experimental studies.
Topics: Animals; Female; Humans; Inbreeding; Male; Mating Preference, Animal; Reproduction
PubMed: 33941905
DOI: 10.1038/s41559-021-01453-9