Seasonality and Adult Habitat Use by Four Diabrotica Species at Prairie-Corn Interfaces
2006
Campbell, L.A. | Meinke, L.J.
Although Diabrotica pest species have been well studied in field corn, Zea mays L., relatively little is known about adult habitat use by pest and nonpest species at prairie-corn interfaces. Therefore, the objective of this work was to compare seasonal patterns of beetles of four Diabrotica species and their use of remnant prairie and adjacent field corn habitats in southeastern Nebraska. The study was conducted at five sites in 2001 and continued at three sites in 2002. The Diabrotica species included D. barberi Smith and Lawrence, D. cristata (Harris), D. virgifera virgifera LeConte, and D. undecimpunctata howardi Barber. Cucurbitacin vial traps were used to monitor Diabrotica populations. Available flowers and Diabrotica use of these flowers were also documented. The virgifera group species (D. barberi, D. cristata, and D. v. virgifera) were closely tied to a primary habitat, corn or prairie, but moved to secondary habitat if relative attractiveness of food sources in the primary habitat decreased; these three species had high initial population densities that decreased over the season. The one fucata group species (D. u. howardi) was found in various habitats, with low initial densities that increased over the season. Habitat type and contrasts in plant phenology seem to be key factors that influenced habitat choice by Diabrotica species; this especially affected the level of noncorn habitat use by pest species D. v. virgifera and D. barberi. Use of crop and noncrop parts of the agroecosystem by pest species suggests that a more holistic approach rather than a single field view may be appropriate when managing corn rootworms.
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