Silver Lining in Giant Asian Hornet Nest
A silver lining has been found in the discovery of the first Giant Asian hornet nest in the US.
The nest was found in northwest Washington State. When state entomologists destroyed the nest last fall, they found a very promising sign for fruit growers in Colorado and other states.
The hornets' nest also contained the first-known detection of Leptopilina japonica in the United States.
Leptopilina japonica is a tiny parasitic wasp that kills the spotted wing drosophila (SWD), which has the potential to cause extensive damage to fruit crops in Colorado as it has around the West.
Daane: “It’s problematic for cherry growers, blueberry growers, cranberry, strawberry. The larva feed inside the fruit where it’s hard for any insecticides to get to them. They cause the fruit to rot.”
Kent Daane with the UC Cooperative Extension in Fresno County speaking to CalAgNet, where the insect has proven to be very damaging to several kinds of fruit crops.
The newly discovered wasp larvae consume the inside of the Spotted Wing Drosophila larvae, eventually killing the fly. This has potential as a better way to manage the spotted wing drosophila. Insecticides are effective but growers often have to spray on a weekly schedule which leads to residue concerns and is expensive. There’s also the fear of pesticide resistance forming.
While the Colorado Department of Agriculture says the Spotted-wing drosophila was found relatively recently in Colorado. Small fruits, especially late bearing raspberries and strawberries, are at particular risk of damage.