The question of 3: What is the purpose of multiple lobed spermathecae in Aedes aegypti and Aedes albopictus?

Recent evidence has indicated that polyandry occurs at low rates in Aedes aegypti and Aedes albopictus, previously considered monogamous. Polyandry is a common mating strategy throughout Insecta and allows for the possibility of female cryptic choice, in which a female preferentially utilizes one male’s sperm over others, post-copulation. One mechanism of female cryptic choice is the use of multiple spermathecal lobes and the asymmetrical distribution of sperm among lobes. Both A. aegypti and A. albopictus have a larger, medial spermatheca and two smaller lateral spermathecae.  We hypothesize that females utilize the different spermathecae depending on mating characteristics: precedence and male quality.  To test this, we conducted mating precedence studies with large and small sized males. We examined which male’s sperm went to which lobe and the proportion of offspring sired by each male. Results and implications will be discussed.