Root feeding beetle larvae



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

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The larval stage of several beetles may attack germinating seeds, seedlings, or the root system of more mature plants. Wireworms, bean leaf beetle, southern corn rootworm, and grape colaspis commonly infest soybean plants (grape colaspis has already been discussed under seedling pests, as well as the adult stage of the bean leaf beetle). Wireworms occasionally attack seeds, seedlings, and roots and may reduce stands in localized spots, however wireworms are very minor pests. Bean leaf beetle larvae and southern corn rootworm commonly infest soybean fields. These soil dwelling larvae are similar in appearance; they are white to yellowish elongate insects (to 5/8 inch) with a dark head and anal shield (plate on last segment). The larvae also feed in a similar pattern by grazing root hairs and root tips and boring into nodules. Grape colaspis larvae may eat the entire root. The soybean plant has an ability to compensate for some root and nodule loss, especially when other factors reduce the plant's need for nutrients and water. Since these insects seldom reach suitably high populations in the soil, plant performance is generally not affected. However, when nitrogen deficiency is diagnosed, these insect pests are a source of suspicion. There are no management strategies designed for these pests.

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/beetle.html) was created by John W. Van Duyn Ph D. Extension Entomologist and Wayne Modlin

Date Created 2/22/00.
Last revised on 2/4/04.

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.