Adults are about 1/2 to 3/4-inch in length. Immature stages vary in color from black for very small nymphs to green for larger nymphs. However, the immature stages have a distinctive pattern of whitish spots on the abdominal segments. Nymphal stages are often found together in high numbers because eggs are laid in clusters that appear as rows of small barrels on and around suitable food sources. Development from egg to adult requires about 35 days, but varies with temperature. Up to five generations per year may occur with greater numbers appearing in the fall before adults overwinter.
Adults deposit barrel-shaped eggs. Immature stages develop through five stages or instars that appear similar to adults except that they do not have fully developed wings. Several generations can be produced each year.
Plant feeder, they also feed on the parts of many ornamental and wild plants. In fruit, such as tomatoes, damage is of two types. When the young green fruit is injured, the cells at the site of feeding are killed by the toxic saliva injected by the bugs into the plant. This area of the fruit stops expanding, while the cells around the dead cells continue to expand by increasing their water content. The result is deformed fruit that appears to have dimples. This type of damage has been called "cat facing." When ripened or nearly ripened fruit is injured, the injection of toxic saliva merely kills a cluster of cells that later forms an off-color hard mass in the fruit, reducing fruit quality and producing a bad flavor to the fruit.
Hand-picking and destruction of the insect pests and egg masses may deter damage where low numbers of insects are found. The bugs may be controlled with dusts or sprays of insecticides applied to the foliage.