Stink bug research could bear fruit in a few years

About five years ago the brown marmorated stink bug migrated into Northern Virginia and began damaging the apple crop and other produce. New research is under way at Virginia Tech and a U.S. Department of Agriculture research center in Maryland to lure away the invasive pest by imitating the chemical pheromone it generates when eating.

“When they first moved in from North to South, the first wave was pretty rough,” said Harman Brumback, a Frederick County farmer and member of the Virginia Farm Bureau Federation Apple Marketing Advisory Committee.

“They’ll actually sting the apple and leave a tiny hole in the fruit. If they do that in the early part of the season, the fruit will then start to rot, or it creates a hard spot. That turns (the apple) into a cull, no good for the fresh fruit business.”

Farmers use chemical controls to reduce stink bug populations, which are extremely hardy. Researchers are attempting to recreate the pheromone that the pest generates when it begins feeding on a plant. The goal of the four-year project is to use genetic engineering to inject that protein into an expendable “trap crop” that would attract stink bugs away from more valuable food crops.

“This could create sort of like a protective barrier to your field,” said Jason Lancaster, a Virginia Tech biological sciences doctoral candidate and research assistant. “We know that once a stink bug lands on a host plant they like, they don’t move very far from it.”
Lancaster plans to identify the first of three proteins in a harlequin bug pheromone compound by the end of this summer. One of the challenges his team faces is that there are dozens of varieties of stink bugs, including harlequin bugs.

“That’s what makes this research all the more difficult. They don’t respond to each other’s pheromones very well,” Lancaster said. “But luckily what we’re seeing with this research is the genes used to make this pheromone are pretty similar. We’re hoping that once we understand the harlequin bug, the other stink bugs will be much easier.”

A common mustard plant has been tentatively identified as a test host for the research, said Dr. Dorothea Tholl, associate professor of biological sciences at Virginia Tech’s College of Science. “We believe if we can engineer these plants, that method will be more sustainable than pesticides that affect a wide range of insects. If the trap plants are attracting some stink bugs away, even a smaller amount, that’s preferred over spray applications that have to be repeated again and again.”

Brumback said stink bugs “are hard to kill, so some biological controls would be good. Some of the insecticides we have to use to kill them knock off other insects, like beneficial insects.”