Lygus Bug

Common: Lygus bug

Scientific: Lygus hesperus

Crop Hosts: Many cultivated crops including seed, alfalfa, cotton, dry beans, fruit trees, strawberries, lettuce, safflower, tomato, carrots and sugar beets.

Identification and Life Cycle: In most regions the bug overwinters as adults in hibernation. The egg stage requires 8 days and the 5 nymphal stages about 11 days. The adults are small, about 1/4-inch long, and the female lays eggs in the flowers, buds, bracts, squares, nodes and internodes. With feeding, nymphs become dark green with 4 noticeable black spots on the thorax. In the summer, a generation requires from 20 to 30 days.

Geographical Distribution: This species occurs primarily throughout the Pacific western states.

Damage and Treatment: The insect injures the tender growing parts causing flowers and buds/squares to drop. In addition to the physical injury, there is a toxic reaction to the plant cells near the puncture point.

Treatment should be made when insect populations and/or damage levels reach economic thresholds. Refer to local University Extension Pest Management Guidelines for specific state thresholds.