Adult insects over-winter under plant debris or thick shrubbery, and on weed growth such as mustards, Russian Thistle, or mallow. They resume activity in early spring, laying clusters of eggs on foliage. The eggs resemble tiny barrels with lids. Development from egg to adult may be around 2 months, with several generations possible each year. Nymphs and adults feed on many kinds of fruits and vegetables, and are a serious pest of tomatoes in California, as well as alfalfa, sugar beets, and cereal grains. When they feed on developing fruits or vegetables they may introduce a yeast that causes decay and loss of the fruit. Feeding with their proboscis also causes dimples, discoloration, or a local hardening of the tissues at the immediate site of penetration.
On crop plants a number of biological controls, both parasites and predators, have been useful. In landscapes even common pillbugs have been found to feed on the egg clusters of stinkbugs. Good cleanup of fallen leaves and other plant debris in the fall will reduce over-wintering sites and remove many of the bugs that have hidden there. Small numbers of the insects on landscape plants may be tolerated and little to no damage would be noticed. For larger infestations a residual contact insecticide applied to the foliage may be effective. Since they also feed on weeds the removal of weed growth, particularly legumes, along the perimeter of crops or landscape will help reduce the numbers of the bugs in the area.