U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2008
Abstract
For many maize (Zea mays) producers across the Midwestern USA, as well as in parts of the northern and southern plains, the corn rootworm complex (Diabrotica spp.; Coleoptera: Chrysomelidae) has represented one of the greatest challenges to efficient, quality maize-grain production over the past 50-60 years. Three species of corn rootworm are particularly troublesome: the western corn rootworm, Diabrotica virgifera virgifera, the northern corn rootworm, D. barberi and the Mexican corn rootworm, D. virgifera zeae; all have consistently been important economic pests of maize (Metcalf, 1986b). Prior to the introduction of transgenic maize varieties designed for corn rootworm management, from 8-10 million ha were treated with soil-applied insecticides to protect maize roots from larval feeding, with no absolute guarantee that the plants would be protected.
Corn rootworms damage maize primarily through larvae feeding on the roots. Severe feeding can result in lodged or stunted plants due to substantial root loss (Chandler, 2003). Over the years prior to the mid-1990s yield losses varied annually, but when the value of those losses was combined with the cost of control, these averaged at around US$ 1 billion per year (Chandler et al., 1998). Adult corn rootworms can also inflict damage to maize plants through feeding on silk and pollen. Large numbers of rootworms feeding on silk can substantially reduce pollination, which interferes with kernel set and reduces yield.
Comments
Published in Areawide Pest Management: Theory and Implementation (eds O. Koul, G. Cuperus and N. Elliott) p. 191-207