Protandry in Aedes Sierrensis: The Significance of Temporal Variation in Female Fecundity

Protandry, the early emergence of males into a seasonally breeding population, has been described mathematically as a mating strategy resulting from sexual selection on both sexes. A key implicit assumption in protandry models is that all matings contribute equally to a male's reproductive success. We build a simulation model of protandry based on field censuses and investigate the consequences of size—specific temporal variation in female fecundity for the optimal timing of protandry in the western treehole mosquito, Aedes sierrensis. We show that theoretical predictions of protandry are robust when differential female fecundity is incorporated into a model of protandry in A. sierrensis. In addition, we utilize field data and laboratory experiments to elucidate the selective forces acting on both sexes of this mosquito. Under conditions of reduced per capita resources, males minimized development time by pupating at lower mass; females maximized mass by delaying pupation. These gender—specific, homeostatic adjustment to food and density, which result in density—dependent protandry, indicate that protandry is the result of selection on independent fitness criteria in each sex.