Document Type

Thesis - Open Access

Award Date

1968

Degree Name

Master of Arts (MA)

Department / School

Entomology

Abstract

The damage caused by corn rootworms (Coleoptera, Chrysomeiidae) results in extensive losses to corn each year in South Dakota. Thousands of dollars are spent each year for the control of these insects. Kantack (1965} reported during 1963 approximately 496,000 acres of corn were severely damaged by corn rootworms in South Dakota. In 1964 corn rootworm infestation increased causing an estimated three million dollars in damage (Kantack, 1965). At present, serious infestations occur in major corn growing regions of southeastern and western South Dakota. Three species of corn rootworms are found in South Dakota: the western corn rootworm, Diabrotica virgifera Leconte; the northern corn rootwonn, Diabrotica longicornis (Say); and the southern corn rootworm, Diabrotica·undecimpuctata howardi Barber. In the state, the western and northern species cause the majority of the rootworm damage. Prior to 1961 the northern corn rootworm was the predominant species found in South Dakota. The western corn rootworm was not as corn on but had been present in the state for many years. Adult western specimens were collected from Jones Co. in 1922 and from Butte Co. in 1930 (Kantack, 1965). The western and northern species can damage corn in various ways. The larvae feed on the root system, eating the young rootlets and tunneling into later developing root stages. Extensive corn damage can result with heavy corn rootworm infestations. This weakens plants and often causes severe lodging and yield reductions. Further injury is caused by adult beetles which emerge from the oil in late July. Adult corn rootworms feed on various parts of the corn plants including the silks and tassels. Pollination may be affected resulting in poorly filled ears where heavy adult populations occur. Additional damage is caused by beetles feeding on the kernels at the tip of the ear.

Library of Congress Subject Headings

Chrysomelidae

Format

application/pdf

Publisher

South Dakota State University

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