The scoop on pesky stinkbugs

A scoop — or shovel, if you prefer to call it that — was about as effective as any weapon Mid-Atlantic farmers tried last year against swarms of brown marmorated stinkbugs, or BSMB. Formerly just a stinking nuisance, the bug exploded into a major crop-insect problem last summer.

“I call it the bug from hell,” says Master Farmer Randy Sowers from Middletown, Md. “We started noticing them a year ago.”

But when son Benjamin took the silage chopper into one field last fall, he could hardly see through the clouds of stinkbugs. Worried about the smell and possible off-tasting silage, they blended that silage with silage from other fields.

“Some spots had no kernels on the ears at all. The corn looked good, but had nothing inside the shucks,” bristles Sowers. Fortunately, the 280-cow dairy herd of Sowers Dairy and South Mountain Creamery showed no signs of feed refusal of the blended silage.

Fruit and vegetable growers in the area reported 100% losses on sweet corn, peppers, tomatoes, late blueberries, fall raspberries and soybeans.

In Pennsylvania, some growers lost 40% to 50% of their tree-fruit crops due to fruit damage, according to Greg Krawczyk, Penn State University tree-fruit specialist. BMSB control in fruits and vegetables is complicated by concerns that broad-spectrum insecticides need multiple applications, and can kill insects used in integrated pest management.

A much wider problem

Large BMSB populations caused severe damage in 2010 to corn, soybean, fruit, vegetable, grape and berry crops in Delaware, Maryland, New Jersey, Pennsylvania, Virginia and West Virginia. By midsummer, a national working group of state, federal and industry experts was convened by the USDA to come up with potential solutions.

The group quickly confirmed that BMSB is established in 27 states nationwide.

“At this point, we don’t have answers for many questions,” reports George Hamilton, co-chairman of the research task force tackling the problem. Hamilton, who is the Rutgers Extension pest management specialist, says scouting protocols are somewhat lacking.

Black light and pheromone traps can be used to monitor BMSB adult activity. “But we don’t have treatment thresholds yet for any crop,” he says.

He strongly recommends scouting for egg masses and newly hatched nymphs. If found, consider using a registered or Section 18 insecticide on the nymphs.

“We’re having great difficulty killing adults in the field,” Hamilton explains. “Of course, this won’t keep BMSB adults from re-entering after applications are made.”

Be aware of what’s being grown around your fields. Adults tend to invade from the perimeter. Once crops such as soybeans start to senesce, adults appear to move to later-ripening vegetables and tree fruit.

“We’re not sure about the residual activity of any insecticides outside of the laboratory,” he cautions. “This will be looked at this next season under field situations.”

USDA’s BMSB Section 18 working group developed a list of promising compounds, without regard to their current label status. They include: Carzol, Dimilin, Beleaf, buprofezin, Diamond, Vydate, Lannate, Brigade, all pyrethroids, Thionex/Thiodan, Orthene, Scorpion, methyl parathion, Baythroid, Belay, Calypso and Actara.

Section 18 requests can be pursued by states without federal regulatory status change. They probably won’t include organophosphate, carbamate or chlorinated hydrocarbon materials, notes Hamilton. “They probably also won’t be a pyrethroid, due to lack of residual action, knockdown recovery issues and impact on beneficials.”

Most labeled products require at least two treatments.

What to watch for

Rutgers Extension entomologist George Hamilton expects to start to see brown marmorated stinkbug eggs and newly hatched nymphs in his area about mid-June. They’ll show up earlier in warmer locations.

The BMSB lays pale-green egg masses, often on leaf undersides. They have five nymphal (instar) stages, with first instar being about one-eighth of an inch in size.

Resembling tiny ticks, first instars are brightly colored red and black, and cluster around the hatched egg mass. Nymphs typically have dark reddish eyes and yellowish-red abdomens with black stripes. Legs and antennae are black with white banding.

For more details, go to njaes.rutgers.edu/stinkbug/
identify.asp
.


This article published in the March, 2011 edition of AMERICAN AGRICULTURIST.

All rights reserved. Copyright Farm Progress Cos. 2011.