Precipitation's complicated role in driving the abundance of an emerging disease vector in an urban, arid landscape

Abstract

Understanding drivers of disease vectors’ population dynamics is a pressing challenge for human health, however, for short-lived organisms like mosquitoes, landscape-scale models must account for the highly local and rapid scale of their life cycle. Aedes aegypti, a vector of multiple emerging diseases, has been increasing in abundance in desert population centers, where water from precipitation could be a limiting factor. To explain this apparent paradox, we examined daily precipitation and Ae. aegypti abundances at >660 trapping locations per year for 3 years in the urbanized Maricopa County (metropolitan Phoenix), Arizona, USA. Through kriging of weather station data, we connected daily precipitation to subsequent trapped abundances of mosquitoes, and determined the timing and amount of precipitation that result in thresholds of interference with mosquito abundance. Large rainfall events resulted in no trapped mosquitoes 6-8 and 13-14 days later, while 10% of all mosquitoes were trapped in long, precipitation-free periods.