Watch for tarnished plant bug
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Tarnished plant bugs have been invading many vegetable crops, probably as a result of nearby alfalfa fields being cut. Tarnished plant bugs feed on a variety of crops, including many vegetables. In most crops they prefer feeding on flowers and fruit, but can also feed on the tips of asparagus fern, celery petioles and lettuce leaves. Adults are very mobile and can move in and out of fields before they are detected. Tarnished plant bugs have sucking mouthparts and insert a toxic saliva into plants while feeding. They can cause tip die back in asparagus, flower drop in peppers, snap beans and tomatoes, brown, sunken feeding scars or stings in lettuce and celery.
Treatment thresholds have not been established in most crops for tarnished plant bug. In celery, Ontario recommends a threshold of 0.2 tarnished plant bugs per plant for celery up to three weeks before harvest and 0.1 tarnished plant bugs per plant for celery less than three weeks before harvest. Because of this pest’s mobility, inspecting plants for damage may be necessary.
Tarnished plant bugs are effectively controlled by a number of insecticides, including pyrethroids, neonicitinoids, and carbamates. Consult bulletin E312: 2008 Insect, Disease, and Nematode Control for Commercial Vegetables for insecticides registered to control tarnished plant bug on your crop.