Harlequin Ladybird

Ladybugs love to snack on aphids and other pests. So people began importing an Asian species called the harlequin ladybird as natural pest control. But in their new environments, the harlequins wiped out native ladybugs. And they have their parasites to thank. That's according to research in the journal Science. A parasite called microsporidia lies dormant in the circulatory systems of harlequin ladybirds. But when scientists injected microsporidia into a common European ladybug species, the insects died within two weeks. When the ladybugs were injected with dead microsporidia or a control substance most survived . Harlequin ladybirds' immune systems, on the other hand, have learned to deal with microsporidia which lets the insects use them as biological weapons .