More than a half million mosquitos are set to be dropped into the greater Washington, D.C. metropolitan area this summer. But don\u2019t worry, they\u2019re on our side.<\/p>\n
For the first time ever, the Maryland-based company Bee Safe Mosquito Control<\/a> is deploying male mosquitoes infected with a particular strain of Wolbachia bacteria into the region. These infected, non-biting males are expected to mate with uninfected females and sterilize them, leading to declining population numbers. Similar programs have already been used in other countries to help curb mosquitoes and the diseases they can spread.<\/p>\n \u201cThe introduction of males in order to control the population is a technique that has been tried time and time again. And it\u2019s worked really well against many species,\u201d Todd Montgomery, owner of Bee Safe, told<\/a> local media outlet WTOP News Monday.<\/p>\n A bacterial ally <\/p>\n Wolbachia are a group of bacteria widely found in a majority of insects, mosquitoes included.<\/p>\n These bacteria have complex relationships with the hosts they naturally infect; some species seem to be harmless passengers, yet others might provide benefits, such as helping produce<\/a> nutrients the insect doesn\u2019t get from its food.\u00a0 With some insects like mosquitoes, Wolbachia can even influence their reproduction through a phenomenon known as cytoplasmic incompatibility.<\/p>\n The bacteria subtly alter both the sperm and eggs of their mosquito hosts. Mosquitoes can only inherit Wolbachia naturally from their mother, when the infection passes through to the egg. When a Wolbachia-infected male mates with a female that\u2019s either uninfected or carrying a different strain of the bacteria, the latter\u2019s modified sperm will actually kill the eggs soon after fertilization. However, the eggs of a female infected with a matching strain of Wolbachia can neutralize this modification, allowing the embryo to develop normally.<\/p>\n Scientists have now started to take advantage of this incompatibility as a kind of biopesticide. Male mosquitoes reared in a lab are infected with a specific strain of Wolbachia (different from the strains that might be found in a natural population) then large numbers of these males are sent into the wild, where they\u2019ll ideally mate with wild females. Since female mosquitoes only mate once, those that hooked up with the lab males will never lay viable eggs; over time, this should reduce the local population.<\/p>\n Several countries such as Brazil, Singapore, and Thailand have<\/a> tested or approved the use of Wolbachia-infected males to lower mosquito populations. And in late 2023, the Environmental Protection Agency granted approval<\/a> for one version of this technique to be used widely in the U.S., which was developed by the company MosquitoMate<\/a> (the company is the commercial spinoff of a research team from the University of Kentucky).<\/p>\n This approval covers modified Aedes albopictus mosquitoes, dubbed ZAP males by the company, and it\u2019s the same mosquitoes that Bee Safe will be using this summer. All in all, the company will be dropping roughly 600,000 ZAP males in the D.C. metropolitan area between June and September. A. albopictus mosquitoes, also known as Asian tiger mosquitoes, can spread diseases such as dengue, Zika, and chikungunya.<\/p>\n The future of Wolbachia mosquito control <\/p>\n Though A. albopictus is a serious vector threat, it\u2019s not quite as dangerous as the Aedes aegypti<\/a> mosquito, the latter of which exclusively feeds on humans.<\/p>\n MosquitoMate has also developed Wolbachia-infected A. aegypti mosquitoes, named WB1 males. And testing is ongoing to confirm the potential of similarly modified mosquitoes in the U.S. Much of this current research is being spearheaded by the Google-owned Debug project, which is hoping to release<\/a> up to 64 million mosquitoes in California and Florida in the near future.<\/p>\n