A chemical that inhibits insect growth may help combat the spread of foodborne bacteria carried by house flies, according to new research from the U.S. Department of Agriculture. Scientists at USDA’s Agricultural Research Service have found that pyriproxyfen – a pesticide that’s been shown to stunt mosquito growth – has the same effect on fly larvae, preventing them from maturing to adulthood. House flies are known to be carriers of foodborne pathogens such as E. coli and Salmonella, which are transmitted via animal fecal matter, where many flies breed. “Pyriproxyfen mimics a hormone in the larval fly,” Chris Geden, an entomologist at ARS, explained to Agricultural Research Magazine. “When it’s applied in sufficient quantities to larval breeding sites such as manure, insects become stuck in the immature stages and they never become adults.” The research team also discovered that they could target larvae by administering the pesticide to adult flies, who then pass it on to immature flies, preventing their growth. Even small amounts of pyripoxyfen were effective in stunting larvae growth when applied to egg-carrynig females, according to Geden. “We found the material extremely effective at low dosages for house flies and that flies are capable of carrying enough back to their breeding sites to prevent the maturation of immature flies,” Geden told Agricultural Research Magazine. “We’re now working with new formulations of higher potency to improve this system.” Scientists administered a dust containing pyripoxyfen to these flies, who then laid eggs that died in their pupal phase, he said. This method of applying the pesticide would mean it could be targeted towards egg-carrying adults rather than being used more widely anywhere a fly might lay eggs.