But the wasps can regroup for a counterattack, too. “This is a real evolutionary arms race between the host and the parasite,” says Christoph Vorburger, Head of the Aquatic Ecology Department. To give the “little helpers” an advantage, he selectively breeds the wasps to help them adapt. This has already been demonstrated in various laboratory experiments.

But can this actually improve biological pest control? “Yes,” says Vorburger, “at least in the laboratory trials.” In their study, which will shortly be published in the trade journal “Evolutionary Applications”, Vorburger and his team demonstrate how: In contrast to wasps that have not been adapted, wasps that have evolved on an experimental basis are able to significantly reduce the population density of resistant pests. Experimental evolution means letting natural selection run its course in the lab through numerous generations. “This kind of pre-adaptation in the lab could also be useful for beneficial insects bred at a commercial level,” says Vorburger.