Mutant Bugs' Task: Destroy Own Species Fruit flies implanted with gene to halt population By Matt Cantor, Newser User Posted Sep 30, 2013 1:19 PM CDT 9 comments Comments Olive fruit flies can destroy 15% to 30% of a year's crop. (Shutterstock) (Newser) – How do you get rid of a population of bugs destroying your crops? Scientists are trying out a controversial method: spreading a gene that prevents females from reproducing. Males can live with the lab-inserted gene, but females die in the larval stage—which doesn't leave a lot of options for reproduction or the future of the species, New Scientist reports. In a lab experiment, this decimated the population in 10 weeks. Scientists at English firm Oxitec want to try their method in Spain, where they're awaiting the OK from Spanish authorities to kill off certain fruit flies that destroy some 15% to 30% of the olive tree crop each year. But genetic science watchdogs have concerns about the method, fearing, for instance, that altered populations could affect creatures outside their own species, Mashable reports. A similar experiment is already happening in the wild in Brazil, where the Oxitec team has altered males of a population of dengue-carrying mosquitoes. Some 96% of dengue mosquitoes around the city of Mandacaru have been destroyed, the company says.