Tarnished Plant Bug

Tarnished plant bugs (Lygus lineolaris) are 1/4 inch, tan to dark brown oval insects with piercing sucking mouthparts. They attack more than 50 different economic crops but are most damaging to strawberries, peppers, tomatoes and all bean crops in Wisconsin. Feeding by these insects causes poor fruit set and gnarled fruit due to the toxic saliva they inject into the plant. They are highly mobile insects that overwinter in field debris and large numbers of adult plant bugs migrate out of alfalfa fields when hay is cut.

In commercial beans, take 25 sweeps with an insect sweep net per sample site with at least 10 sample sites per 100 acres. When counts exceed one tarnish plant bug per sweep in a field, control measures are recommended succulent and dry beans

Refer to the UW-Extension publication Commercial Vegetable Production in Wisconsin (A3422) for an updated list of registered insecticides and management recommendations.