Harlequin bug

Chewing pests

Harlequin bug adults are 10 mm long, robust and shield-shaped. Adults are brightly colored in black and red-orange with distinct yellow markings. There is a black X on the thorax.

Harlequin bug

Harlequin bug adults and nymphs use their piercing-sucking mouthparts to withdraw plant fluids, causing plants to wilt, turn brown and possibly die. Nymphs resemble adults but are smaller and lack wings. Eggs are laid on leaf undersides and are very distinctive, resembling tiny white kegs standing on end in a double row. Each egg has two dark bands, one near the top and one near the bottom. Harlequin bug overwinters as an adult.

Harlequin bug eggs


Remove weeds and plant debris from adjacent areas that may serve as over-wintering sites. Keep grassy areas mowed during the spring and summer. Contact insecticides may be effective in controlling harlequin bug adults and nymphs.

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The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.