Tarnished Plant Bug


Tarnished plant bug aren't picky eaters.

They feed on fruits, vegetables, and ornamental plants. Tarnished plant bugs are spindly legged, small insects, both as nymphs and adults, that move rapidly when disturbed. Adults are 1/4 inch long, brown, flat-topped, with many angular black markings. Nymphs are smaller and greenish, with a few tiny dark spots.

Damage Caused by the Tarnished Plant Bug

Tarnished plant bugs feed on over 350 types of plants, including asparagus, beans, beets, carrot, cauliflower and broccoli, potato, tomato, peaches, strawberries, and ornamental plants. They most commonly feed on the buds and new shoots with their piercing-sucking mouthparts. 

Feeding damage can cause spotted and deformed leaves and stems, die-back, young fruit or buds to die, and fruit to be deformed. 

Life Cycle of the Tarnished Plant Bug

Adult tarnished plant bugs overwinter in plant litter in fields, woods, timber margins, ditch banks, and rights-of-way. 

  • In the spring and early summer, females insert elongate, slightly curved eggs into the stems, leaf petioles, and leaf mid-ribs of a variety of plants. 
  • Eggs take 1 to 2 weeks to hatch, depending on temperature. 
  • Nymphs develop through 5 stages and take 2 to 4 weeks to reach the adult stage, again depending on temperature.
  • Two to four generations develop each year, with greater numbers in the southern part of the state and in warmer years. 

Management of the Tarnished Plant Bug

Tarnished plant bugs are common on pigweed seed heads, so check them in the vicinity of the bean field. Five or more bugs per twenty-five sweeps is enough to warrant treatment.

  • Do not mow the pigweeds near bean bloom because mowing will cause the bugs to migrate to the beans.
  • Use a sweep net to check for bugs in the beans.

Contact your county Extension office for current pesticide controls.