Controlling Mosquito Larvae in Urban Drainage Structures in Arizona

Mosquitoes are important human disease vectors worldwide. In Arizona, the primary species of concern are Culex tarsalis and Culex quinquefasciatus, both of which can transmit West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). Aedes aegypti is also a common urban vector with the potential of transmitting Zika, chikungunya and dengue viruses, although local transmission in Arizona has been rare. Treatment options for these viruses in humans are limited, so controlling the mosquito vector and reducing human/vector contact remain the best disease prevention strategies. Before they develop into the adult stage, all mosquitoes are aquatic (Fig. 1). Therefore, controlling the mosquito population at the immature (larval) phase is ideal as the mosquitoes are confined to a water source during this stage. Larval control in the water source can be achieved either by removing the source or treating the water with insecticides or biological agents. The goal is to prevent the mosquitoes from reaching the adult stage when they can acquire and transmit pathogens causing human and animals diseases.