Harlequin bugs attack crops in the Brassicaceae family. Plants commonly attacked include broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard, radish and turnips.
Growers can typically identify harlequin bug damage by the yellow or white blotches the bugs leave behind when feeding on the plant. The pest sucks fluids from plant tissue, which can result in wilted or deformed plants. Heavy infestations can cause plants to turn brown and die.
“It’s important to identify pest damage early on,” said Daniel Frank, WVU Extension Service entomology specialist. “The sooner you begin control methods, the less likely you are to see significant crop loss.”
Harlequin bugs are in the stink bug family and are black with bright red, yellow or orange markings.
The pests often remain throughout the winter; they seek shelter in crop residues and other organic debris such as dead leaves, mulch or bunches of grass.
It is possible to manage or minimize the damage caused by harlequin bugs, Frank said.
Destruction of crop residues in the fall helps to limit harlequin bug damage the following year. Because this insect can also feed and reproduce on wild, weedy mustards, it is important to keep weeds under control in fields and along field edges. Handpicking insects can also be effective if performed regularly while populations are low.
There are chemical options for controlling the pest, according to Frank.
Chemical options include numerous compounds in the pyrethroid and neonicotinoid class of insecticides. Pyrethrins are permissible in organic production.
For additional information on other pests and control options, contact your local county office of the WVU Extension Service, or visit anr.ext.wvu.edu/pests.
CONTACT: Cassie Waugh, WVU Extension Service
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