Researchers seek answers this winter
Researchers hope to answer a few of the pesticide questions this winter. They will begin to screen both registered and unregistered pesticides as possible short-term control to help growers survive another season, says Greg Krawczyk, an Extension fruit entomologist at Penn State University who’s involved in the pesticide screening.
The screening will involve rearing marmorated stink bug colonies in the laboratory, then subjecting them to different compounds to determine residual activity.
“We know how to kill them—that’s not the problem,” says Krawczyk, who’s based at Penn State’s Biglerville Fruit Research and Extension Center. “When the insect contacts the spray, it will die. That’s the way we do it at the moment. We don’t know if the [pesticide] residual doesn’t affect them or there’s such a huge influx that they’re able to overwhelm the residual.”
In the end, he says, more sustainable, longer-term solutions will be needed.
“It’s not sustainable for growers to go and spray every seven days to eliminate newcomers to the orchard, Krawczyk says. “Our short-term goal is to give growers something they’ll be able to do. We have to help growers now so there will still be growers a few years from now.”
Longer-term goals include developing treatment thresholds and learning more about stink bug behavior, alternate hosts, biological control and pheromone-based mating disruption, says Tracy Leskey, a research entomologist at the Agricultural Research Service’s Appalachian Fruit Research Station in Kearneysville, W.Va.
Best trapping methods
Last season researchers also looked at the best traps to monitor marmorated stink bug populations in fields and orchards. Black says he offered up his orchard so he could gain first-hand knowledge of pest populations, stink bug movement and fruit damage.
In the wild, marmorated stink bugs emit a chemical that attracts tens if not hundreds of other stink bugs to an area.
ARS researchers in Beltsville, Md., have identified that chemical, known as an aggregation pheromone, Leskey says. The chemical isn’t quite ready for field testing, although she hopes it will be by next season.
During the 2010 season, Leskey tested a black pyramid trap modified specifically for stink bugs in six commercial fruit orchards. It contained a generic stink bug lure that’s commercially available. At the peak, one trap caught about 1,500 stink bugs during a one-week period.