The Times West Virginian

October 15, 2013

Harlequin bug feeding on state’s vegetable crops

By Emily Gallagher
Times West Virginian

MORGANTOWN — With the weather staying warmer, more farmers and gardeners are extending the time they allow their crops to grow.

According to Daniel Frank, an entomology specialist with the West Virginian University Extension Service, a certain insect has been spotted in West Virginia that attack plants. This is the harlequin bug, which feeds on vegetable crops.

“They’re typically more of a problem in the South; they like the warmer climates,” Frank said.

Frank said the pest will attack crops in the Brassicaceae family including broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard, radish and turnips.

“They leave white and yellow spots,” he said. “If they continually feed, you’ll see the plant start to wilt. The leaves will start to wilt, turn brown and eventually die.”

The harlequin bug is in the stink bug family. Frank said the look of the harlequin bug can range in different colors.

“They can be orange, yellow or red,” he said. “And they’ll have a black marking.”

Frank said the harlequin bug has became more of a problem in West Virginia because there are more people growing cruciferous crops and vegetables.

“They also feed on weedy crops too, they’re in that same family,” he said.

With winter approaching, Frank said the harlequin bug will take cover in nearby leaves.

“Whatever crop they were on, they’ll be in that leaf litter,” he said.

Frank said for those who do have gardens, to help get rid of them, gardeners and farmers should clean up any crop residue or debris.

“That limits their overwintering shelter,” he said. “They’ll freeze and basically die.”

For now, Frank said gardeners should check on their gardens as much as possible. He said if harlequin bugs start showing up, one of the best things gardeners can do is to hand pick them off of the plant.

“You can knock them into a bucket of soapy water,” Frank said.

With an overwhelming amount of harlequin bugs, Frank said there are insecticides to control the pest including compounds in the pyrethroid and neonicotinoid class of insecticides.

“I’ve had people tell me that the bug has completely wiped out their crop, mostly with kale,” he said. “They didn’t get out there soon enough to really see what was going on.”

For larger growers, Frank said having a trap crop can also help keep the harlequin bug away. A trap crop is a crop that is planted away from the primary crop.

“For example, if you’re growing kale, you’ll plant another kale patch a little bit earlier, maybe two or three weeks earlier,” Frank said. “Then when the harlequin bugs start developing, that trap crop of kale will be where they are, and you can burn that crop or use insecticides to kill the bugs.”

Frank said consumers of these crops should not worry if what they are eating has been damaged by the harlequin bug because of the process they have to go through to get cleared to eat.

“They’re not going to be in the final product when consumers buy it,” he said.

Frank said the reason the harlequin has been seen more is because of the larger amount of rain West Virginia has seen recently.

“They like weeds, and with the rain we have a lot more weeds,” he said.

Keeping weeds under control can also help keep the harlequin bug away from primary crops.

Email Emily Gallagher at or follow her on Twitter @EGallagherTWV.