What’s sex got to do, got to do with it? Hunger-dependent antipredator behavior, protandry, and size dimorphism of two Aedes mosquitoes

Diverse taxa display protandry, the earlier emergence or arrival of males. This phenomenon could arise due to sexual selection, natural selection, or both. Morbey and Ydenberg (2001) present seven hypotheses for the evolution of protandry, two of which were tested using Aedes mosquitoes as model organisms. By varying food availability and measuring disparity in emergence time, this study tests the hypothesis that protandry in A. albopictus and A. triseriatus is maintained by selection on different fitness components for males and females through a combination of constraint on female fecundity and mating opportunity for males.

Sex-specific modification of behaviors in the presence of predators or predator cues is widespread among animals. Costs of this behavioral change depend on fitness effects of lost feeding opportunities and, because of sexual size dimorphism and protandry, these costs are expected to differ between the sexes. Larval Aedes triseriatus and Aedes albopictus were used to test the hypothesis that behavioral responses of the sexes have been selected differently due to different energy demands.  Females generally spent more effort on higher-risk, higher-reward foraging, consistent with their greater adult size and energy demand. The change in response to predation cues did not differ between the sexes.