“But this insect [the brown marmorated stink bug] is right out there in the spring because it has no problem overwintering.”
An aggressive feeder
The brown marmorated insect has a long stylette, or feeding tube, that it inserts into the plant and sucks out the plant juices. The stylette is so strong that it can pierce a tough corn husk to get to the tender kernels underneath, Dively says.
“I couldn’t believe that it could actually get through the husk,” Dively says.
As it feeds, the stink bug injects saliva that contains a plant enzyme and a plant toxin.
In apples, the toxin turns the plant tissue surrounding the feeding area into a corky mass, rendering them unsuitable for the premium fresh market.
In tomatoes and peppers, this stink bug also injects yeast organisms that lead to eventual fruit rot.
Dively says the saliva or toxin also affects the plants, causing the fruit to be misshapen.
The brown marmorated stink bug has five immature life stages, or instars, and all of those—as well as adults—are capable of damaging fruit and plants.
Few natural enemies
Most stink bugs lay eggs that resemble small barrels close together. Brown marmorated stink bug eggs resemble pearls.
In the United States, small, parasitic wasps lay their eggs in native stink bug eggs and provide biological control. Since the marmorated stink bug is a foreign invader, Dively says no one knows whether there are native beneficial insects that will parasitize the eggs.
In China, where the pest is native, researchers report up to 50 percent egg parasitism from a small wasp.
In the United States, a small tachnid fly will lay its eggs in the bodies of native stink bugs, Dively says. The immature feed internally and emerge from the stink bug body as an adult, killing the stink bug in the process.
But the native tachnid flies don’t seem to survive in brown marmorated stink bugs, he says.