The Tarnished Plant Bug, Lygus lineolaris, is the most common plant bug found in the United States and feeds on cotton, soybeans, and over 50 other crops. They pierce plant parts and fruiting structures to extract plant juices and may make cotton bolls abort or make less seed germination in plants. In cotton, damaged pinhead squares may show a slight discoloration of the infected anthers. In fruits and vegetables, damage may appear as indented or cat-faced injury.
Nymphs are yellow-green and have 4 black dots on their backs. First and second instar nymphs have very long legs and antennae. Adults are broad, flattened, and oval with light brown coloration broken by brown, black, and yellow markings. A pale, Y-shaped mark is present on the scutellum, and along the posterior of the body a clear yellow triangular region is marked with a black triangular dot. They grow up to 1/5 inches.
They are active throughout the year in the south, but in the north they overwinter as adults. The spring adult females insert eggs into succulent plant tissues and young nymphs hatch 10-21 days later and develop through 5 instars over 3 weeks. The summer life cycle from egg to adult takes approximately 4 weeks.
TPB Nymph TPB Adult