The role of male harassment on female fitness for the dengue vector mosquito Aedes aegypti
Sexual harassment studies in insects suggest that females can incur several kinds of costs from male harassment and mating. Here, we examined direct and indirect costs of male harassment on components of female fitness in the predominantly monandrous mosquito Aedes aegypti. To disentangle the costs of harassment versus the costs of mating, we held females at a low or high density with males whose claspers were modified to prevent insemination and compared these to females held with normal males and to those held with females or alone. A reduced longevity was observed when females were held under high-density conditions with males or females, regardless if male claspers had been modified. There was no consistent effect of harassment on female fecundity. Net reproductive rate (R 0) was higher in females held at low density with normal males compared to females held with males in the other treatments, even though only a small number of females showed direct evidence of remating. Indirect costs and benefits that were not due to harassment alone were observed. Daughters of females held with normal males at high density had reduced longevity compared to daughters from females held without conspecifics. However, their fitness (R 0) was higher compared to females in all other treatments. Overall, our results indicate that A. aegypti females do not suffer a fitness cost from harassment of males when kept at moderate densities, and they suggest the potential for benefits obtained from ejaculate components.
KeywordsAedes aegypti Monandry Harassment Longevity Net reproductive rate
We are thankful to all members of the Harrington laboratory at Cornell for their support, to Elizabeth Glennon and Melissa Hardstone for assisting with egg collection and counting, and to Laura Sirot, Lauren Cator, and anonymous reviewers for constructive comments on our manuscript. This study was supported by the Foundation for the National Institutes of Health through the Grand Challenges in Global Health Initiative (GC7 #316), and by NIH/NIAID grant R01AI095491.
All experiments comply with the current laws of the country in which they were performed.
Conflicts of interest
The authors declare that they have no conflict of interest.
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