Bean leaf beetle


John Van Duyn, North Carolina State University, Entomology Extension Specialist

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This small dark colored beetle overwinters in woods and around field edges. Beetles tend to emerge from overwintering before soybean planting and the first full-season soybeans to sprout in an area will attract many of the strong flying beetles (beetles are small, ca. 1/4 inch, have light yellow to reddish wings with four black spots, and a "V" pattern at the front of the wing covers -- the spots may be missing on some beetles). If colonization is heavy the beetles can occasionally cause severe seedling defoliation. Feeding appears as almost round holes eaten through the leaves. In severe situations, where defoliation is above 30%, insecticide treatment of seedlings may be warranted. As seedlings become larger and fast growing, this foliage loss is seldom of concern. Whereas bean leaf beetle is a common insect of soybean seedlings in the Tidewater region, it seldom requires treatment at this locale or anywhere in NC. Several virus diseases are spread to soybean plants by the bean leaf beetle adults; notably bean pod mottle virus, cowpea mosaic virus, and southern bean mosaic virus. The transmission of these viruses may become important on late-season soybeans, after the virus has had a chance to build-up in the early season. However, controlling the bean leaf beetle with insecticides has not been considered an effective way to reduce virus infection.


Soybean Page

Other Resources

    1. North Carolina Agricultural Chemicals Manual
    2. North Carolina Cooperative Extension Service

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This page (http://www.ces.ncsu.edu/plymouth/pubs/BLBJVD.html) was created by John W. Van Duyn Ph D. Extension Entomologist and Wayne Modlin

Date Created 2/22/00.
Last revised on 2/04/04. Published by North Carolina Cooperative Extension Service

Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University at Raleigh, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

CAUTION: The information and recommendations in these Notes were developed for North Carolina conditions and may not apply elsewhere.