The tarnished plant bug is a common pest on numerous vegetable, fruit and flower crops, as well as a number of weeds. It is found throughout the United States, and attacks over 500 commercial crops. Vegetable hosts include bean, beet, cauliflower, cabbage, chard, celery, cucumber, potato, turnip and dill; fruits include apple, peach, pear, strawberry and most other deciduous and small fruits. It also attacks many flowers including dahlia, aster, calendula, chrysanthemum, cosmos, gladiolus, poppy, salvia, daisy, sunflower, verbena, zinnia and others.

Damage:

The tarnished plant bug is a true bug (order: Hemiptera), with the crossed wings and piercing-sucking mouthparts characteristic of this order of insects. The piercing-sucking mouthparts are inserted into the plant tissues, concurrently introducing a toxic saliva into the plant and feeding. This pest causes various types of injury, including deformed leaves (as in beets and chard) and scarred, discolored stems or leaf petioles. In a number of fruits, the buds of the developing fruit are dwarfed and pitted. The tops of dill plants are often killed and blackened above the feeding wound.

Description:

The tarnished plant bug is a small, flattened bug, about 6 mm (1/4 inch) long, generally brown in color, and mottled with splotches of white, yellow, reddish-brown and black. Tarnished plant bugs develop through five nymphal stages. The nymphs are very small and greenish-yellow, marked dorsally with four black dots on the thorax and one on the abdomen. Like the adults, the nymphs have piercing-sucking mouth parts and feed on plant tissues. The wings of the adults have a hard wing cover similar to that of a beetle with a smoky-brown membranous tip. The adults will fly readily when disturbed.

Tarnished plant bug adult (R.A. Casagrande)

Life Cycle:

The adult bugs hibernate among weeds, leaves and bark through the winter. They emerge early in the spring and fly to host plants to feed, later migrating to other plants to lay eggs on the leaves or flowers. The life cycle is completed in approximately three to four weeks, and there are from three to five generations per season. By midsummer there may be great numbers of tarnished plant bugs present, but they are well camouflaged and often go unnoticed.

Control:

Tarnished plant bugs can be difficult to control. Cultural control practices include the removal of weeds and the elimination of trash and other debris which could provide overwintering sites. Mowing grass and weeds around gardens may also help to reduce breeding sites. Verify that insecticides are labeled for use on the tarnished plant bug and follow label directions carefully.

Adapted from G.R. Nielsen, University of Vermont Extension, 1999