By JOSH FLINT
First confirmed in Cook County, Ill., in 2010, to date brown marmorated stinkbugs have largely been an academic concern.
According to University of Illinois entomologist Mike Gray, the pest was found in three additional counties (McLean, Champaign and Kane, Ill.) last year. As it continues to spread, many wonder how long it will be until populations are large enough to cause significant damage to crops. University of Maryland entomologist Galen P. Dively says it could realistically be a matter of only five years or so.
Dively says the brown marmorated stinkbug, or BMSB, first showed up in the United States in the mid-1990s. It has become one of the most devastating pests in the Northeast.
• Brown marmorated stinkbugs showed up in Illinois two years ago.
• This new stinkbug first arrived in the U.S. in the mid-1990s.
• Researchers have yet to find an effective way to manage this pest.
“This is the worst pest I’ve ever seen in my entire career,” says Dively, who is now a professor emeritus with the University of Maryland. “Some of the numbers we’ve seen are what I call ‘Biblical.’ ”
The invasive species is native to China, Japan and Korea. Unfortunately, this means it is well-adapted to overwintering in cold-weather states.
The BMSB life cycle begins in May when adults emerge from overwintering in wooded areas and homes. After feeding, they lay eggs, which hatch in the early summer months. Since the BMSB is relatively new, Dively says a lot has yet to be learned about it. However, most entomologists agree one to two generations are common during the growing season.
Using its piercing/sucking mouth parts, the BMSB feeds primarily on fruity structures and seeds. Dively has documented instances of BMSBs piercing the husk and feeding on sweet-corn kernels during the milk stage. On soybeans, they pierce the pod and feed directly on the bean. BMSBs also feed on numerous vegetable and fruit crops.
On the edge
Much like Japanese beetles, Dively notes BMSB populations congregate at fields’ edges. In fact, he has yet to see one more than 100 feet inward from the edge rows in a soybean field. Unfortunately, field-perimeter treatments have yet to work effectively. In many situations, populations are built back up to pre-spray levels in just a few days, Dively adds.
Thus far, the only way to effectively control the insect is by spraying fields multiple times with certain pyrethroids and neonicotinoids, Dively says. “The problem is, it has totally undermined all of our IPM [Integrated Pest Management] methods in the fruit industry,” he notes. The insect will put a lot of Maryland’s organic fruit growers out of business, Dively adds.
The situation has become so dire, Northeastern researchers are exploring the possibility of introducing another foreign species — the parasitic wasp. In China, BMSB populations are unable to reach the same levels as parasitic wasp species feed on BMSB hatchlings.
Dively says scientists are experimenting with parasitic wasps to see if they will be harmful to other native species. The parasitic wasps will feed on all U.S. native stinkbug species, even the beneficial ones.
Reaching Biblical proportions
In the Northeast, BMSB populations have reached severe-agricultural-problem status. That’s on top of the nuisance status that results from setting up shop in single-family homes. Already the bug has reached the homeowner nuisance level in Kentucky, Ohio, Tennessee and neighboring Indiana. University of Maryland entomologist Galen Dively expects it will become an ag threat in the next few years.
Once the pest is detected (where Illinois currently stands), it takes only a few years to reach nuisance levels. After that, another few years and it’s a severe ag problem.
Dively notes older homes are more easily invaded by the brown marmorated stinkbug. Unfortunately, there is no good way to rid a house of an infestation. “In homes, you basically have to bite the bullet and live with them,” he adds.
INVASION READY: The brown marmorated stinkbug is an excellent hitchhiker. University of Maryland entomologist Galen Dively says they can squeeze their way into a sealed automobile with no problem.
Photo by Michael Jeffords, Illinois Natural History Survey
This article published in the February, 2012 edition of INDIANA PRAIRIE FARMER.
All rights reserved. Copyright Farm Progress Cos. 2012.