[ST01] Diverse environmental drivers of malaria infection in Anopheles mosquitoes

The transmission of many vector-borne pathogens is strongly influenced by environmental temperature, via effects on the physiology of the insect vector and the pathogen. Therefore, changes in local environmental conditions could significantly impact the distributions and dynamics of a range of vector-borne diseases. Predicting the extent of possible changes in disease dynamics will require a detailed understanding of how a suite of vector-pathogen traits respond to variation in environmental temperature. Here, we explore how realistic variation in mean ambient temperature (27 o C, 30 o C, and 33 o C), diurnal temperature range (DTR 0 o C, 6 o C, and 9 o C), and time of day of infection (18:00 and 02:00h) influence the vector competence of two principle malaria vectors, Anopheles gambiae and An. stephensi, to the human malaria parasite, Plasmodium falciparum. We demonstrate that overall, increasing mean temperatures and DTRs significantly reduce parasite burden and the proportion of infectious mosquitoes for both vector species. Further, there are significant interactions between mean ambient temperature and DTR, with effects of diurnal fluctuation on vector competence becoming more severe at warmer environmental temperatures. Finally, the time of day mosquitoes take an infectious bloodmeal integrates with diurnal temperature fluctuation to influence vector competence. These results suggest that variation in microclimate dynamics associated with changes in land use, housing structures, or climate, as well as shifts in mosquito feeding behavior associated with insecticide-treated bed net coverage, could lead to important changes in the ability of Anopheles mosquitoes to vector malaria.