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Northern and Western Corn Rootworm in South Dakota

Written collaboratively by Adam Varenhorst, Mike Dunbar, Patrick Wagner, Amanda Bachmann, Bradley McManus and Billy Fuller


Northern corn rootworm (NCR), Diabrotica barberi Smith & Lawrence, and western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, are major pests of corn throughout North America. Populations of both species are common in South Dakota. The adults can be readily found in cornfields from July through the first fall frost. However, the greatest economic losses are associated with larvae feeding on corn roots, which begins in early June and continues until adult emergence.