By Vicky Boyd
Growers and even homeowners in the Northeast and Mid-Atlantic states are under siege from a smelly foreign invader that has a wide host range, can render crops unmarketable for fresh uses, has few native enemies and is extremely mobile.
To top it off, only a handful of broad-spectrum pesticides are known to control the brown marmorated stink bug. Because the insecticides are non-selective, they also kill beneficial insects, upsetting biological control.
“I grew up on a farm in the Midwest, and we had stink bugs. But the level of destruction [from this pest] on field crops was absolutely stunning,” says Mark Seetin, director of industry policy and regulatory affairs for the Vienna, Va.-based U.S. Apple Association. “It’s of grave concern. I can’t rate it any higher in terms of a potential threat for the reasons that it’s voracious, it feeds in all five instars, it likes apples and very few pesticides have been found to work on it at this stage.”
In response to the pest, scientists within the U.S. Department of Agriculture and several universities formed a working group last summer to set research priorities and begin conducting trials.
USApple, at the prompting of Maryland apple grower Robert Black, convened a meeting in late October to bring lawmakers, researchers and association members up to speed on the pest.
Few pesticide choices
One of the challenges is few registered pesticides will control the marmorated stink bug. Select pyrethroids and Lannate appear to kill it, says Galen Dively, an emeritus professor of entomology at the University of Maryland in College Park. But they are contact products and provide short residual control.
Brown marmorated stink bugs are highly mobile. Shortly after a grower treats a field or orchard, new stink bugs move in from the outside, returning populations to where they were before treatment.
The insecticides also are broad spectrum and kill beneficial insects, which are part of an integrated pest management program.
For Black, who owns Catoctin Mountain Orchard in Thurmont, Md., weighing stink bug control against an integrated pest management program that he spent more than a decade building was a tough decision.
“We spent the last 12 to 15 years doing IPM and have a huge predator population,” he says. “Here we are building our predator populations up, and we’ll wipe it out in a year. I hadn’t used pyrethroids for years, but I did on my later varieties in hopes of salvaging them.”