FEMA FAQ: Mosquito Spraying
Austin Joint Field Office
Q: Harvey created many flood areas where mosquitoes are flourishing. What is being done to combat the problem?
A: The Texas Department of State Health Services, together with FEMA, began aerial insecticide spraying over Refugio and Bee counties Sept. 7 from dusk to dawn, when mosquitoes are most active.
Q: Is aerial application of insecticide dangerous?
A: Aerial spraying does not present a risk to people, pets or other animals. A small amount of insecticide, one to two tablespoons per acre, is dispersed by airplanes equipped with nozzles that spray tiny droplets. The droplets float in the air for a period of time and kill adult mosquitoes on contact. Droplets that settle to the ground quickly break down. According to the Environmental Protection Agency, people may prefer to stay inside when spraying takes place, but it is not necessary.
Q: Is there an increased chance of contracting West Nile virus and Zika due to this situation?
A: Most mosquitoes that appear after floods are nuisance mosquitoes that don’t spread disease. Standing water does increase the number of mosquitoes capable of spreading West Nile virus and Zika. Primarily, however, their biggest nuisance is that they can stall recovery operations by preventing people from being outside.
Q: What can I do to help solve the problem?
A: People can help control mosquitoes during the recovery effort by dumping standing water and applying a commercially available larvicide in water that can’t be drained. People should also use an EPA-registered mosquito repellent each time they go outside, and keep mosquitoes out of homes using good window and door screens.