Questions about Aerial Mosquito Control

What’s the situation with mosquitoes after Harvey?

  • The rain left behind by Hurricane Harvey has created large areas where mosquito eggs can hatch.
  • Large numbers of mosquitoes are starting to emerge, first along the southern part of the area affected by Harvey and then further up the coast, and threaten to hamper recovery efforts.
  • Most mosquitoes that appear after floods are nuisance mosquitoes that don’t spread disease but can have a serious effect on recovery operations by preventing responders and people affected by a disaster from being outside.
  • Areas of standing water can also increase the number of mosquitoes capable of spreading diseases like West Nile virus and Zika.
  • To combat the threat these mosquitoes can cause to recovery efforts and public health, the Texas Department of State Health Services has activated its aerial mosquito control contract with Clarke and requested additional mosquito control assistance from the FEMA.

Why aerial spraying?

  • Aerial spraying is only one part of the solution for controlling mosquitoes, but it is the one method that can rapidly reduce the number of mosquitoes in a large area.
  • It is the most effective method when large areas must be treated quickly.

How does it work?

  • A small amount of insecticide, one to two tablespoons per acre, is dispersed by airplanes equipped with special nozzles that create ultra-low volume droplets specifically calibrated to affect mosquitoes.
  • The tiny droplets float in the air and kill adult mosquitoes on contact.
  • Any remaining droplets start to break down immediately in sunlight and water.

Is aerial spraying of insecticides harmful to people, pets or livestock?

  • No. During aerial spraying, a small amount of insecticide is sprayed over a large area, one to two tablespoons per acre.
  • When applied according to label instructions by a licensed professional, it does not pose a health risk to people, pets or the environment in the area.
  • EPA-registered products are used for aerial spraying, and label instructions will be followed by a licensed professional.
  • If people prefer to stay inside and close windows and doors when spraying takes place they can, but it is not necessary.

Are there any effects on lakes and rivers used for drinking water or recreation?

  • No. Because the small amount of insecticide breaks down quickly when it comes into contact with water, it has no lasting effects.

Will aerial application harm bees?

  • Spraying will be done in order to minimize any effects on bees.
  • Applications will be done starting around dusk when mosquitoes are most active and after bees have returned to the hive for the night. The insecticides dissipate and break down quickly in the environment, and when bees emerge in daylight, they are not affected.
  • We do not anticipate any impact to bees or other non-target species.
  • Though pesticide applications around dusk and dawn will not cause a significant exposure to bees, beekeepers may choose to cover their colonies and prevent bees from exiting during treatment.

Are there precautions people should take?

According to the EPA, people may prefer to stay inside and close windows and doors when spraying takes place, but it is not necessary. Those who are especially concerned about chemicals may choose to take some of these steps to help reduce exposure:

  • Pay attention to specific information on spraying in your area.
  • Stay indoors with the windows closed during spraying.
  • If you are outdoors when spraying takes place and come in contact with the chemical, rinse your skin and eyes with water.
  • Wash fruits and vegetables from your garden before storing, cooking, or eating.
  • Cover outside items like furniture and grills before the spraying takes place. Bring pets and items like pet food dishes and children’s toys indoors. Rinse any uncovered items left outside before using.
  • If you think you have had a reaction, talk to your doctor or call the regional Poison Control Center at 1-800-222-1222.

What about protected areas like wildlife refuges?

  • Insecticide won’t be sprayed over wildlife refuges and other sensitive areas. The areas where spraying will occur have been cleared by the U.S. Fish and Wildlife Service to avoid impacts on refuges and endangered species.

What can people do to combat mosquitoes and mosquito bites?

  • People should dump out standing water around their homes and businesses and apply a commercially available larvicide in water that can’t be drained.
  • People should also avoid mosquito bites by using an EPA-registered mosquito repellent every time they go outside and making sure their window and door screens are in good repair after the storm to keep mosquitoes out of homes.