Texas Mosquito Control Response Following Hurricane Harvey.

Hurricane Harvey has been recorded as the wettest cyclone in United States history, resulting in devastating and catastrophic flooding for the Texas Gulf Coast. The nature of the path of the hurricane, with multiple landfalls along the Texas Gulf Coast, resulted in the largest aerial mosquito control effort for one single storm. Two mosquito control contractors and the Air Force Aerial Spray Unit of the US Air Force Reserve were used to aerial treat 6,765,971 acres (3,075,441 ha) in 29 of the 60 disaster-declared counties in Texas. During the response, 101,253 liters of Dibrom® (active ingredient [AI]: naled) and 48,735 liters of Duet™ (AI: 1% prallethrin and 5% sumithrin) were used. In 23/29 counties requesting aerial spraying, mosquito control contractors were used to conduct pre- and postaerial application mosquito surveillance. The remaining 6 counties conducted their own surveillance during the response. A total of 105,153 mosquitoes in 7 genera and 35 species were collected during this response with the major floodwater nuisance mosquito being Psorophora columbiae. The most abundant vector mosquito collected was Culex nigripalpus. Duet at the 0.8% and 1% application rates resulted in 49% and 69% control of Ps. columbiae, respectively. Dibrom application resulted in 95% and 93% control of Ps. Columbia and Cx. nigripalpus populations, respectively.