Emerging Mosquito Control Technologies

Traditionally, mosquitoes have been managed with conventional adulticides and larvicides; however, as technology advances, companies are discovering innovative ways to control mosquito populations. Some mosquito technologies, which modify mosquitoes to prevent female offspring from survive to adulthood, have the potential to reduce mosquito populations and the use of traditional mosquito products.

Since 2012, EPA has evaluated several emerging mosquito population control technologies, which are based on two different approaches:

  • Wolbachia infected mosquitoes
    • Wolbachia are naturally occurring bacteria that are used to infect mosquitoes to reduce mosquito population. Several Experimental Use Permits and one registration have been issued.
  • Genetically modified mosquitoes
    • Modified male mosquitoes carry a gene that results in female offspring not surviving. One Experimental Use Permit (including one product amendment and extension) has been issued.

Although these technologies use different methods to modify mosquitoes, the technologies share several similarities. Both mosquito technologies introduce male mosquitoes, which do not bite humans, into wild populations to mate with females that are already present in the area. The male mosquitoes pass along traits or Wolbachia bacteria that do not allow female offspring to survive; therefore, recurrent release of male mosquitoes result in fewer offspring and consequently, population decline. Additionally, for both technologies, the pesticidal activity is species specific which limits the impact to non-target organisms.

To learn more about each technology, read the Q&A section below.

On this page:

Genetically Modified Male Mosquitoes Developed by Oxitec

What is the purpose of Oxitec's Experimental Use Permit?

Oxitec developed genetically engineered Aedes aegypti (OX5034) mosquitoes that are intended to reduce the local mosquito population. Oxitec’s Experimental Use Permit (EUP) will gather data to determine whether OX5034 mosquitoes are effective at reducing the number of Aedes aegypti mosquitoes before the company decides whether to apply for a geographically broader or nationwide FIFRA registration. Aedes aegypti mosquitoes, which is an invasive mosquito species in the United States, can transmit diseases such as dengue, Zika, and chikungunya to humans; therefore, mosquito control is important for protecting human health. Additionally, the use of modified mosquitoes could reduce the use of chemical pesticides for mosquito control. This may be especially beneficial for densely populated communities with environmental justice concerns. These communities could be at higher risk for exposure to mosquitoes, virus transmission, and exposure to pesticides from mosquito control.

How does the technology result in mosquito population decline?

OX5034 males carry a gene (tTAV-OX5034) that is passed on to their offspring and that allows their male offspring to survive while their female offspring do not. With continued releases of the OX5034 males throughout the mosquito season, the absence of female mosquitoes emerging in the release area results in mosquito population decline.

Where can Oxitec conduct field testing and for how long?

OX5034 males carry a gene (tTAV-OX5034) that is passed on to their offspring and that allows their male offspring to survive while their female offspring do not. With continued releases of the OX5034 males throughout the mosquito season, the absence of female mosquitoes emerging in the release area results in mosquito population decline.

Where can Oxitec conduct field testing and for how long?

In April 2020, EPA approved the initial Experimental Use Permit (EUP), which allowed Oxitec to field test the use of OX5034 mosquitoes on 6,240 acres of Monroe County, Florida, and 360 acres of Harris County, Texas, through April 2022 to evaluate the effectiveness of OX5034 mosquitoes at reducing local mosquito populations.

  • Extends the EUP until April 30, 2024, on 5,360 acres of Monroe County, Florida. This extension will generate additional data to evaluate the effectiveness of OX5034 mosquitoes at reducing mosquito populations.
  • Expands the EUP to four counties in California, consisting of 29,400 acres in Stanislaus, Fresno, Tulare, and San Bernardino counties. Oxitec may conduct testing in these areas until April 30, 2024, to generate efficacy data in different climatic zones.
  • Removes Harris County, Texas, from the approved testing locations.

The Florida Department of Agriculture and Consumer Services and the California Department of Pesticide Regulation must approve testing in their states before testing can take place.

Will this testing adversely affect human health or the environment?

No. Like all pesticides, Oxitec's genetically engineered mosquitoes are regulated under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and therefore must meet the statutory requirement of no unreasonable adverse effects to humans or the environment to be granted an Experimental Use Permit (EUP). Prior to approving the EUP, EPA conducted extensive evaluation of the best available science, considered public input, and consulted with technical experts at the U.S. Centers for Disease Control and Prevention (CDC). Only male OX5034 mosquitoes will be released into the environment. Because male mosquitoes do not bite humans, they do not pose a human health risk.

As part of EPA’s risk assessment for the EUP amendment, including the extension in Florida and the expansion to California, the Agency examined whether the release or consumption of OX5034 male mosquitoes would harm endangered species or any other organisms such as birds, bats, or fish and determined that no discernible effects are anticipated to these organisms. Additionally, animals are not expected to be harmed from the potential reduction in the local Aedes aegypti population because predators that eat mosquitoes generally have a diverse diet and none are known to use Aedes aegypti mosquitoes as a sole or critical food source.

EPA determined that OX5034 mosquitoes meet FIFRA standards of not causing unreasonable adverse effects to humans or the environment.

To view the supporting materials, including EPA’s risk assessments, visit docket EPA-HQ-OPP-2019-0274 at regulations.gov.

What protection measures are in place for the Experimental Use Permit?

The Experimental Use Permit (EUP) contains significant protections. To ensure that no OX5034 female mosquito offspring survive, EPA has taken the precaution of restricting release of OX5034 mosquitos within 500 meters of potential sources of tetracyclines, as there is a remote chance that environmental sources of tetracycline could have enough tetracycline present to act as a counter agent to the OX5034 female mosquito-lethal trait. Releases must not occur within 500 meters from the outer perimeter of 1) wastewater treatment facilities; 2) commercial citrus, apple, pear, nectarine, and peach crops; and 3) commercial cattle, poultry, and pig livestock facilities. The 500-meter distance creates a conservative buffer zone between OX5034 release points and potential environmental tetracycline sources.

Additionally, EPA mandates that Oxitec monitor and sample the mosquito population every week to ensure no OX5034 female mosquito offspring survive. When potential environmental tetracycline sources exist within 1,000 meters of mosquito release sites, Oxitec must monitor for OX5034 female mosquitoes within 100 meters of those potential environmental tetracycline sources. No genetically modified female OX5034 mosquitoes have been detected during Oxitec’s field testing so far, and detection of OX5034 females are not expected based on EPA’s risk assessment. Should an OX5034 female be detected, Oxitec must cease releases of all OX5034 mosquitoes and apply adulticide and larvicide pesticides to the treated area where the surviving females were detected and continue to monitor for the presence of OX5034 female mosquitoes.

In the event of tropical storms, hurricanes, known advancing wildfires, or other significant natural disasters, Oxitec will return the boxes used for rearing and releasing the OX5034 mosquitoes to a secure facility.

Once the experiments have concluded, Oxitec must conduct post-release monitoring until no OX5034 mosquitoes have been found for at least two successive mosquito generations, a minimum of 10 consecutive weeks. EPA continues to maintain the right to cancel the EUP at any point during the 24-month period.

How Can I Learn More About Oxitec's EUP?

Read EPA's announcements:

  • May 10, 2018: “EPA Reopens Public Comment Period on Application for Experimental Use Permit to Combat Mosquitoes”
  • September 11, 2019: “EPA Receives Request for Experimental Permit to Combat Mosquitoes”
  • May 1, 2020: “EPA Approves Experimental Use Permit to Test Innovative Biopesticide Tool to Better Protect Public Health”
  • April 30, 2021: “Attend EPA’s Webinar about the Experimental Use Permit for the Oxitec Genetically Engineered Aedes aegypti Mosquitoes”
  • August 31, 2021: “EPA Seeks Public Comment on Proposed Amendment to Experimental Use Permit for Genetically Engineered Mosquitoes”
  • March 7, 2022: “Following Review of Available Data and Public Comments, EPA Expands and Extends Testing of Genetically Engineered Mosquitoes to Reduce Mosquito Populations”

Watch EPA's webinar:

Visit additional webpages related to Oxitec's testing:

View documents related to the 2020 EUP

View documents related to the 2022 EUP Amendment:

Wolbachia Mosquitoes Developed by MosquitoMate

What is the purpose of MosquitoMate’s technology and how does it differ from conventional mosquito control?

The purpose of MosquitoMate’s technology is to reduce local populations of Aedes aegypti and Aedes albopictus mosquitoes. These species are invasive mosquitoes in the United States, and can transmit diseases such as dengue, Zika, and chikungunya to humans; therefore, mosquito control is important for protecting human health. Additionally, the use of modified mosquitoes could reduce the use of chemical pesticides for mosquito control.

How does this technology result in mosquito population decline?

MosquitoMate had developed two mosquito products that rely on the same underlying technology. Wolbachia pipientis is a bacterium that is present naturally in about 60 percent of insect species, including many mosquito species. Naturally occurring strains of Wolbachia are used to infect captive male Aedes mosquitoes, which are then released into the wild. When a Wolbachia infected male mosquito mates with a wild female mosquito who carries a different strain of Wolbachia or who is not infected with Wolbachia, neither male nor female offspring survive due to a phenomenon called cytoplasmic incompatibility. With continued releases of infected males, the native mosquito population in the release area ultimately declines.

Where can MosquitoMate’s technology be used?

ZAP Males, the product used for suppression of Aedes albopictus, is registered for commercial use in all U.S. states and territories

On April 14, 2024, WB1 Males, the product used for suppression of Aedes aegypti was registered for commercial use in all U.S. States and territories. 

Will this technology adversely affect human health or the environment?

No. Like all pesticides, MosquitoMate’s technology is regulated under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). MosquitoMate's technology will only be used in male mosquitoes. The mosquito gender separation process used for Wolbachia male mosquitoes for release is highly efficient. Since male mosquitoes do not bite and do not feed on blood, they do not significantly contribute to the exposure of humans to the Wolbachia strains. The expected accidental release rate of one Wolbachia infected female for every 250,000 infected males is considered negligible exposure to humans resulting in a negligible human health risk. Therefore, when used according to the label, these mosquitoes meet FIFRA standards of not causing unreasonable adverse effects to humans or the environment.

Additionally, the Wolbachia bacterium is a ubiquitous microbe that humans and the environment have been exposed to. It is estimated to be present in about 60 percent of insects, some crustaceans, and nematodes.

To view the supporting materials for these emerging mosquito technologies, visit docket EPA-HQ-OPP-2016-0205 and EPA-HQ-OPP-2017-0392 at regulations.gov.

What requirements are in place as a part of MosquitoMate's FIFRA Section 3 registrations?

In evaluating a pesticide registration application, EPA assesses a variety of studies to determine the likelihood of adverse effects (i.e., risk) to occur from exposures elicited by the use of the product before a registration decision is made. Risk assessments are developed to evaluate how the active ingredient might affect a range of non-target organisms, including humans and terrestrial and aquatic wildlife (plants and animals).

Based on the results of these assessments, EPA evaluates and approves language for each pesticide label to ensure the directions for use and safety measures are appropriate to mitigate any potential risk and ensure the efficacy of the product. In this way, the pesticide label communicates essential limitations and mitigations that are necessary for public and environmental safety. The mosquito specific requirements for ZAP Males and WB1 Males are as follows:

Bi-annual reporting to EPA to ensure that quality control measures are being adhered to including any exceedance of the required 1 female per 250,000 males in any production batch, and if there is any reduction in ZAP Males or WB1 Males fitness and viability.

Any batches of ZAP Males or WB1 Males  that do not pass the standards of the approved quality control measures must be halted;

Quarterly environmental monitoring for establishment of the ZAP strain among Aedes albopictus mosquitoes in the environment where ZAP Males are actively being released. If ≥10% of A. albopictus eggs or larvae sampled from a site per visit are confirmed positive for the ZAP strain in two consecutive visits (with the subsequent visits conducted monthly), then MosquitoMate must cease releases within 3 km of the positive site. Releases may resume if an additional mosquitocide is used or if <10% of A. albopictus eggs or larvae are positive for the ZAP strain during subsequent monthly monitoring. ;

Quarterly environmental monitoring for establishment of the WB1 strain among Aedes aegypti mosquitoes in the environment where WB1 Males are actively being released. If ≥10% of A. aegypti eggs or larvae sampled from a site per visit are confirmed positive for the WB1 strain in two consecutive visits (with the subsequent visits conducted monthly), then MosquitoMate must cease releases within 3 km of the positive site. Releases may resume if an additional mosquitocide is used or if <10% of A. aegypti eggs or larvae are positive for the WB1 strain during subsequent monthly monitoring. ; and

Any occurrence of ZAP-infected females or WB1-infected females in the environment must reported to EPA within 30 days of detection.

To learn more about the protection measures in place, read the labels here.

How can I learn more about MosquitoMate’s mosquito technology?

Read EPA's announcement:

  • Dec 5, 2023: “EPA Approved Additional Use of Biopesticide to Help Suppress Mosquito Populations that Spread Diseases
  • Nov 7, 2017: “EPA Registers the Wolbachia ZAP Strain in Live Male Asian Tiger Mosquitoes”

Find Product Information on EPA's Webpages?

View documents related to the current Wolbachia-pipientis ZAP Strain in Aedes albopictus registration:

View documents related to the current Wolbachia-pipientis WB1 Strain in Aedes aegypti registration: 

View documents related to the expired Wolbachia pipentis wAlbB Strain in Aedes aegypti 89668-EUP-3 Experimental Use Permit:

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Last updated on October 8, 2024