Natural enemy of invasive, berry-eating fly present in U.S.

A parasitoid wasp that’s the pure enemy of a fly often called the spotted-wing drosophila might be a great buddy to growers. Washington State University researchers not too long ago confirmed the invention of the doubtless helpful wasp within the United States for the primary time. 

The drosophila flies trigger main injury to a number of Washington crops, particularly candy cherries and berries. The wasp, which lays its eggs within the flies, might be a method of controlling their unfold.

“This is really a positive step for the cherry and berry industries,” stated Elizabeth Beers, a professor in WSU’s Department of Entomology. “Hopefully this speeds up the timeline to get biological control of the spotted-wing drosophila.”

Beers and her crew discovered the parasitoid, referred to as Ganaspis brasiliensis, this September, in a wild blackberry patch lower than a mile from the Canadian border close to Lynden, Washington. The tiny wasp was present in western British Columbia in 2019. Paul Abram, a Canadian colleague, requested Beers to look at for wasps crossing the border and supplied recommendations on the most effective locations to search out them.

Another parasitoid of the drosophila pest, Leptopilina japonica, was additionally present in British Columbia in 2019 and in Washington state in 2020 by Chris Looney of the Washington State Department of Agriculture. But the brand new parasitoid which is native to South Korea has a significant profit: specificity.

“The Ganaspis is very host-specific; it really likes to attack spotted-wing drosophila larvae and generally doesn’t bother other species,” stated Beers, who is predicated at WSU’s Tree Fruit Research and Extension Center in Wenatchee.

The invasive drosophila fly hurts fruit as a result of it would not simply nibble on the surface—its larvae burrow down right into a raspberry or cherry and break your complete factor. That’s the place the parasitoid comes into play.

Beers stated it is simply potential to see the tiny grownup parasitoids flying round drosophila-infested fruit. The feminine Ganaspis then lay their eggs contained in the drosophila larvae. The little parasitoid develops contained in the drosophila larva, killing it within the course of.

“It’s a bit like the movie Alien,” Beers stated. “It’s unpleasant to think about in sci-fi movie terms, but really effective for killing spotted-wing drosophila.”

The Ganaspis parasitoids have been not too long ago accredited by the U.S. Department of Agriculture Animal and Plant Health Inspection Service to be reared and distributed across the U.S. as a biocontrol.

To try this, an entomologist went to the native residence of spotted-wing drosophila, discovered the Ganaspis, and brough again a number of samples. After important analysis in quarantine, it was discovered to be secure to unfold right here to struggle drosophila.

During that course of, the Ganaspis discovered its personal technique to North America and is spreading with out assist. Once an invasive species is discovered dwelling in a state, the USDA doesn’t regulate it being distributed round that state, making the method simpler.

“It’s kind of the best of both worlds,” Beers stated. “It’s great that we have a lot of research showing that Ganaspis is very host-specific and safe to spread around. But there are also benefits to it being found here in nature.”

This is the third unique species that Beers and her lab has present in the previous couple of years. They discovered a parasitoid of the apple mealy bug, a pest for the apple business, and the Samurai wasp.

“I never anticipated this, it’s not the main focus of our lab,” Beers stated. “We’ve just kind of stumbled across them as part of our research on various pests.”