Mosquitoes, the most dangerous beasts on earth, have killed more people than all the wars in history. They often sniff out human prey, which is why scientists have spent several years studying the tiny insect’s powerful sense of smell. And while the research may not go far in stopping the spread of such deadly diseases as malaria (bed nets, insecticides, and other options seem more effective), it may allow scientists to create better bug sprays, according to a Seattle Times article. Whether those superior repellents will ever hit the market, however, is another question.
Many of the new options being explored function by impairing or manipulating a mosquito’s sense of smell. One, called the Kite Patch, is a cloth square that, “allows humans to go virtually undetected by mosquitoes for up to 48 hours,” according to maker, Olfactor Laboratories, a startup that raised $557,000 on the crowdfunding site Indiegogo. The patch, which is not yet on the market because it still has to undergo third-party safety and effectiveness testing, is infused with non-toxic compounds that block the insect’s ability to detect carbon dioxide, which the startup says is “their primary method of tracking human blood meals.”
CO2 isn’t all that attracts mosquitoes. The tiny buggers have more than 80 odor receptors, all tuned in to specific scents ranging from the cholesterol on our skin to the body odors emitted by beer drinkers, which mosquitoes love.
Laurence Zwiebel, who heads up a research lab at Vanderbilt University, has praised a compound called VUAA1, which may be 100,000 times more effective than DEET. It functions by turning on all the mosquito’s smell receptors at once, causing a sensory overload.
Despite all the progress, it may be a while before new repellents and compounds hit the market and replace DEET. The holdup has to do with the prohibitive costs of entering the bug spray market, which could be as high as $200 million.
Why so expensive? One cost is scaling up production to an industrial level. “It can be a very time-consuming and expensive process,” says Zwiebel of Vanderbilt. “Each synthesis route brings in a novel group of impurities and those impurities may be toxic. … So you have to lock down the production route before you can register a product.”
Other costs include securing intellectual property rights and getting regulatory approval from the U.S. Environmental Protection Agency and sometimes, the U.S. Food and Drug Administration. “There may be little boutique products that comes out that use natural compounds that have less regulatory issues, but a real game changer like DEET—a DEET substitute is going to require an agro-chemical component,” says Zwiebel, meaning that it can be used as a pesticide. While the market for personal and spatial repellents is in the millions, he explains, “agriculture changes that to billions. …You need to have something that works on a wide range of insects, some of which are agricultural, some of which are nuisance, some of which are medical vectors.”
Until scientists and companies find something that meets all those needs, which may not be for years, we probably won’t get a better bug spray. Still, progress is underway. Says Zwiebel, paraphrasing Winston Churchill: “It’s not the beginning of the end, but it is the end of the beginning.”