These illnesses are often difficult to control, and mosquitoes have gotten better at resisting chemical pesticides that used to work. A fungus called Metarhizium can be used to deactivate mosquito sperm, keeping the deadly ones from spreading disease. “Before this study, longifolene wasn’t known to attract mosquitoes. Image: Mark Sherwood and Raymond St. Leger. “If mosquitoes evolve to avoid longifolene, that could mean they’ll stop responding to flowers,” St. Leger explained.