ZAP Male Mosquitoes: Taking “Bites” From Disease-carrying Mosquito Populations

Imagine the perfect summer day: You’re at the pool, a picnic, or a park, sharing delicious food and stories, while having a great time with your friends and family. 

Then, you hear the piercing, high-pitched buzz in your ear. You glance down and see mosquitoes swarming your arms and legs. You try to swat them all, but most of them escape, leaving you with red welts and a lingering itch that lasts for days. You can’t help but worry that these mosquitoes carry deadly diseases such as malaria, Zika virus, dengue fever, or West Nile.

Humans have always been trying to combat mosquitoes. Pesticides and repellents including DEET and plant extracts are common chemical methods. Physical methods, such as bug zappers and mosquito nets, are also widely used. 

However, some of the emerging mosquito-control technologies that have the potential to turn the mosquito-control industry upside down are biological. MosquitoMate’s ZAP Male mosquitoes take this approach. These mosquitoes are purposely infected with a naturally occurring insect bacterium, Wolbachia. 

Wolbachia is found worldwide due to its evolutionary success with strategies to stay in mosquito populations. It uses a strategy where an uninfected female mates with an infected male, producing a sterile, non-hatching batch of eggs. This technique “punishes” uninfected or resistant mosquitoes, eliminating them from the population and increasing the bacterium’s survival.

Entomology Professor at the University of Kentucky, Stephen Dobson, and his team discovered a new way to introduce Wolbachia into mosquitoes. He wanted to bring his discovery to fruition. However, he couldn’t find a company to take it to market. Undeterred, he decided to start his own company, MosquitoMate. “Either we let [the idea] die because there’s nobody out there who does it, or we form a company and try to move it forward on our own,” said Dobson. “That’s how MosquitoMate was born.”

Dobson and his team discovered that they could deliberately infect male mosquitoes with the ZAP strain of Wolbachia and release them to mate with uninfected females, creating sterile eggs.

This ZAP Male technology has advantages over other controls—such as genetically engineering mosquitoes, trapping, and zapping—in many ways. Unlike many biological mosquito-control solutions, Dobson’s approach does not rely on genetic engineering, a common concern for consumers. Additionally, his unique methodology involves releasing infected mosquitoes of a targeted invasive species—the Asian tiger mosquito, which entered the United States in used tires shipped from Asia in the mid-1980s—rather than all mosquitoes. Since these Asian tiger mosquitoes are disrupting the native ecosystems and food webs, the ZAP Male technology will help to alleviate those problems, too.

 “In the U.S. ecosystem, these mosquitoes are new,” Dobson explained. “If we were to completely eliminate [Asian tiger mosquitoes] from the ecosystem, we’d basically be going back to 1984.” 

 Turning an idea into a company and product is a huge challenge. After the initial breakthrough, Dobson and his team faced extensive regulatory hurdles. Since the ZAP Male technology is revolutionary and has almost no precedent, getting approval from the Environmental Protection Agency (EPA) took a lot of work. “So the problem was that what we’re doing is completely different from what other people have done in the past,” Dobson said. “And that’s been the biggest challenge that we’ve faced very recently. It’s taken years to get [ZAP Male mosquitoes] through the process, and that’s largely because this is just so different from what’s normally done.”

The EPA has required numerous logistically challenging studies on the transmission of this bacteria, along with, more importantly, countless efficacy trials in different places. These trials consisted of boxing off two areas: one test and one control. ZAP Male mosquitoes were released into the test area, and traps were set to catch and monitor the mosquito population. The results were promising, with the population being reduced by as much as 90%. Unfortunately, these trials were subject to many obstacles. “After three months, [one trial location] had a hurricane… [and we] had to stop the trial prematurely. [Then] “COVID hit, and we’d have people who… can’t work in that area because these people have to be quarantined,” Dobson said. “So it’s complicated.”

Luckily, Dobson and his team persevered through these complications, completing these trials, and the EPA approved MosquitoMate’s ZAP Male mosquito treatment in 2023. Dobson is seeking states’ approval and permits and hopes to start mosquito control next year. One day, not in the distant future, you could enjoy the outdoors with 90% fewer mosquitoes, with a lot more fun and peace of mind.