What to know
- Wolbachia (wohl-bach-ee-uh) is a common type of bacteria found in insects.
- Wolbachia bacteria cannot make people or animals sick.
- Mosquitoes with Wolbachia can be used to reduce numbers of Aedes aegypti mosquitoes.
- The Environmental Protection Agency (EPA) regulates use of mosquitoes with Wolbachia. State and local authorities must approve release of these mosquitoes.
About Wolbachia and mosquitoes
Wolbachia is a common type of bacteria found in insects. Approximately 6 in 10 of all insects, including butterflies, bees, and beetles, around the world have Wolbachia. Wolbachia bacteria cannot make people or animals (for example, fish, birds, pets) sick.
Wolbachia bacteria are not found in Ae. aegypti mosquitoes. However, scientists can introduce Wolbachia into Ae. aegypti mosquito eggs.
- Aedes aegypti can spread viruses including dengue, Zika, and chikungunya.
- Aedes mosquitoes are common throughout many areas of the United States.
Researchers have found that Aedes mosquitoes with Wolbachia can be used to reduce numbers of target mosquito species, not other types of mosquitoes. The use of mosquitoes with Wolbachia is regulated in the United States by the EPA.
Mosquitoes with Wolbachia are not genetically modified.
How mosquitoes with Wolbachia are produced and used
Production
- First, Wolbachia bacteria are introduced into male and female Ae. aegypti mosquito eggs.
- From these eggs, new mosquitoes with Wolbachia are bred. The mosquitoes are mass-produced in a factory.
- Male and female mosquitoes with Wolbachia are sorted. Only males are kept.
- Females are not released but may be used for breeding in the laboratory.
Use for mosquito control
Mosquitoes with Wolbachia can be used to reduce numbers of target mosquito species, for example, Ae. aegypti mosquitoes. Mosquito control professionals release male Ae. aegypti with Wolbachia into an area with wild Ae. aegypti.
- When male Ae. aegypti mosquitoes with Wolbachia mate with wild female mosquitoes that do not have Wolbachia, the eggs will not hatch.
- Because the eggs don't hatch, the number of Ae. aegypti mosquitoes decreases.
Did you know?
Only female mosquitoes bite. They need a blood meal to produce eggs. Male mosquitoes do not bite. They feed on nectar from flowers.
Effectiveness in reducing numbers of mosquitoes
Communities in Texas and California that have released mosquitoes with Wolbachia report a significant drop in the number of Ae. aegypti mosquitoes. Singapore, Thailand, Mexico, and Australia have successfully used these mosquitoes. Puerto Rico evaluated use of these mosquitoes as a control method in Ponce.
- When mosquitoes with Wolbachia stop being released into an area, the Ae. aegypti mosquito population will slowly return to "normal levels."
- Mosquitoes with Wolbachia will only work to reduce numbers of target mosquito species, not other types of mosquitoes.
Complements other mosquito control methods
Mosquitoes with Wolbachia only target a specific type of mosquito. Most communities have many types of mosquitoes. Therefore, to control other types of mosquitoes an integrated mosquito management approach should continue being used.
No risk to people, animals, or the environment
Wolbachia are very common bacteria found in insects throughout the world. Once an insect dies, the Wolbachia also will die and decompose in the environment.
- The type of Wolbachia used in mosquitoes are the same types of Wolbachia found throughout the world in many types of insects.
- Every day, insects with Wolbachia are around us.
- There is no data to suggest that Wolbachia bacteria cause any harm to people, animals, or the environment.
Wolbachia bacteria cannot make people or animals (for example, fish, birds, pets) sick.
The EPA determined that mosquitoes with Wolbachia are not likely to harm the environment.
Mosquitoes with Wolbachia and disease outbreaks
Release of mosquitoes with Wolbachia is not intended to stop an outbreak. However, releasing mosquitoes with Wolbachia over several months can reduce the number of a specific mosquito species, such as Ae. aegypti.
- Reducing numbers of mosquitoes that can spread germs can help reduce the chance of an outbreak starting.
- The best way to prevent disease outbreaks is to control mosquitoes before an outbreak happens.
Regulation
Prior to releasing mosquitoes with Wolbachia into an area, EPA must grant an Experimental Use Permit (EUP). Releasing these mosquitoes requires approval from the EPA and local authorities.
- See EPA-HQ-OPP-2015-0374 on Regulations.gov. The EPA has issued, amended, and/or extended other experimental use permits (EUP) using this same technology in another mosquito species, Aedes polynesiensis or Aedes albopictus in 2012, 2013, and 2014.
- Information on those EUPs is available in Docket EPA-HQ-OPP-2012-0181 and Docket EPA-HQ-OPP-2013-0254 at Regulations.gov.