Relationship between leaf litter identity, expression of cytochrome P450 genes and life history traits of Aedes aegypti and Aedes albopictus

Allelochemicals present in the leaf litter consumed by mosquito larvae may play a critical role in mediating the outcome of interactions between mosquito species. To examine this possibility, monospecific and heterospecific cultures of Aedes aegypti L. and Ae. albopictus Skuse larvae were reared under five types of leaf species and the relationship between larval tolerance to leaf litter, expression of 5 cytochrome P450 genes and life history traits determined. For both mosquito species, survival to adulthood was significantly higher in black alder, black walnut, and cypress infusion compared to sugar maple and eastern white pine infusion. In pine but not in other leaf treatments, the presence of Ae. albopictus had significant positive effects on Ae. aegypti wing length and development time to adulthood. Aedes albopictus from heterospecific cultures were larger than those from monospecific cultures and were smaller and took longer to develop in pine and sugar maple infusions than in the other infusions. Up regulation of CYP6Z6 and CYP9M9 in Ae. aegypti and Ae. albopictus respectively appeared to be closely associated with the deleterious effects of sugar maple infusion on mosquito performance as was the down regulation of CYP6N12 (in Ae. aegypti) and lack of induction of CYP6Z6 and CYP9M9 (in Ae. aegypti and Ae. albopictus respectively) in pine infusion. Results suggest that metabolic capabilities that enable the two species to tolerate natural xenobiotics are associated with a fitness cost.