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United States Department of Agriculture

Agricultural Research Service

Research Project: PEST BIOLOGY, ECOLOGY, AND INTEGRATED PEST MANAGEMENT FOR SUSTAINABLE AGRICULTURE Title: Screening Maize Germplasm for Resistance to Western and Northern Corn Rootworms (Chrysomelidae: Diabrotica spp.)

Authors
item Prischmann, Deirdre
item Dashiell, Kenton
item Schneider, David
item Hibbard, Bruce

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 19, 2007
Publication Date: December 11, 2007
Citation: Prischmann, D.A., Dashiell, K.E., Schneider, D.J., Hibbard, B.E. 2007. Screening Maize Germplasm for Resistance to Western and Northern Corn Rootworms (Chrysomelidae: Diabrotica spp.). National Entomological Society of America Meeting, San Diego, CA, December 9-12, 2007.

Interpretive Summary: Corn rootworms (Coleoptera: Chrysomelidae) are devastating pests of maize (Zea mays L.), with a subterranean larval stage that consumes root tissue. To lessen reliance on soil insecticides and provide alternatives for genetically modified maize hybrids, researchers have developed novel maize germplasm and evaluated its resistance and/or tolerance to corn rootworm larvae. Historically, evaluations of corn germplasm have focused solely on western corn rootworms, even though different rootworm species frequently co-exist in soil. Here we report the results of an ongoing research project assessing the resistance and tolerance of four maize genotypes to both western (Diabrotica virgifera virgifera LeConte) and northern (Diabrotica barberi Smith & Lawrence) corn rootworm larvae. Corn lines were planted in field plots previously managed under a four-year rotation of corn, soybeans, oats, and winter wheat to ensure that experimental corn plots were not contaminated by feral rootworm populations. We used a randomized complete block design replicated four times, and mechanically infested plots with 1,000 D. virgifera eggs per 30 cm, 1000 D. barberi eggs per 30 cm, or an agar only control. Resistance and tolerance to immature rootworms were evaluated using previously established methods, including the Iowa 1-6 root damage rating scale, adult rootworm emergence, root dry weight, and compensatory root growth ratings. Differences in maize germplasm and rootworm species will be discussed.

Technical Abstract: Corn rootworms (Coleoptera: Chrysomelidae) are devastating pests of maize (Zea mays L.), with a subterranean larval stage that consumes root tissue. To lessen reliance on soil insecticides and provide alternatives for genetically modified maize hybrids, researchers have developed novel maize germplasm and evaluated its resistance and/or tolerance to corn rootworm larvae. Historically, evaluations of corn germplasm have focused solely on western corn rootworms, even though different rootworm species frequently co-exist in soil. Here we report the results of an ongoing research project assessing the resistance and tolerance of four maize genotypes to both western (Diabrotica virgifera virgifera LeConte) and northern (Diabrotica barberi Smith & Lawrence) corn rootworm larvae. Corn lines were planted in field plots previously managed under a four-year rotation of corn, soybeans, oats, and winter wheat to ensure that experimental corn plots were not contaminated by feral rootworm populations. We used a randomized complete block design replicated four times, and mechanically infested plots with 1,000 D. virgifera eggs per 30 cm, 1000 D. barberi eggs per 30 cm, or an agar only control. Resistance and tolerance to immature rootworms were evaluated using previously established methods, including the Iowa 1-6 root damage rating scale, adult rootworm emergence, root dry weight, and compensatory root growth ratings. Differences in maize germplasm and rootworm species will be discussed.

Last Modified: 12/21/2014
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