Mating mix-up with wrong fly lowers libido for Mr. Right. Duke Today, March 16, 2017. If you’ve ever suffered a nightmare date and were hesitant to try again, fruit flies can relate. Female flies that have been coerced into sex by invasive males of the wrong species are less likely to reproduce with their own kind later. Invasive species are known to threaten native biodiversity by bringing in diseases, preying on resident species or outcompeting them for food. But these results show invasives pose a risk through unwelcome advances, too.