Natural History
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| Tarnished Plant Bug (Lygus lineolaris) - State of Maine |
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| Washington State University |
Young nymphs are tiny and light green in color. Older nymphs are larger, with noticeable black dots on their back, and well-developed wing pads. Young tarnished plant bug nymphs can easily be confused with aphids.
In alfalfa, a new generation can mature about the time the alfalfa is cut for forage. The new lygus bug generation leaves alfalfa seeking another crop.
The tarnished plant bug is among the most damaging of the true bugs and is known to transmit plant diseases. The bugs use their needle-like mouthparts to extract plant juices. Their feeding causes terminal growth to be yellowed or distorted thereby reducing plant growth and causing them to appear unthrifty. Leaves from damaged buds are sometimes ragged and discolored. Adults and nymphs of Lygus lineolaris feed by sucking plant juices and a watery saliva is simultaneously injected into the feeding site to aid in the breakdown of plant tissues.
Management Strategies
Lygus bugs have several natural control agents. A tiny fairy wasp (Anaphes ovijentatus) in the family Mymaridae parasitises the eggs of the lygus bug. Nabid plant bugs, big-eyed bugs, and spiders occasionally prey on young lygus bug nymphs. A European wash, Peristenus digoneutis, has been introduced into alfalfa fields in eastern North America where it parasitises about 40 percent of the tarnished plant bugs. One of the few parasitoids of lygus adults is a tachinid fly, Alophorella spp.
Additional Information
Plant Bugs (Miridae) - American Museum of Natural History
Insect Lygus Bugs - Washington State University
Lygus Bugs - North Dakota State University
Tarnished Plant Bug - Dept. of Agriculture, State of Maine
Lygus Bugs - Manitoba Agriculture
Family Mymaridae - UC Riverside
Family Mymaridae - USDA
