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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #365900
Research Project: Productive Cropping Systems Based on Ecological Principles of Pest Management

Location: Integrated Cropping Systems Research

Title: Field-evolved resistance of northern and western corn rootworm (Coleoptera: Chrysomelidae) populations to corn hybrids expressing single and pyramided Cry3Bb1 and Cry34/35Ab1 Bt proteins in North Dakota

Author
item CALLES-TORREZ, VERONICA - North Dakota State University
item KNODEL, JANET - North Dakota State University
item BOETEL, MARK - North Dakota State University
item FRENCH, BRYAN - Retired ARS Employee
item FULLER, BILLY - South Dakota State University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2019
Publication Date: 5/22/2019
Citation: Calles-Torrez, V., Knodel, J.J., Boetel, M.A., French, B.W., Fuller, B.W. 2019. Field-evolved resistance of northern and western corn rootworm (Coleoptera: Chrysomelidae) populations to corn hybrids expressing single and pyramided Cry3Bb1 and Cry34/35Ab1 Bt proteins in North Dakota. Journal of Economic Entomology. https://doi.org/10.1093/jee/toz111.
DOI: https://doi.org/10.1093/jee/toz111

Interpretive Summary: The ability of northern (NCR) and western corn rootworms (WCR) to consistently thwart management practices such as crop rotation and insecticides demands that we conceive and employ novel control tactics. Today, genetically modified (Bt) corn plants produce one or more proteins that are toxic to corn rootworms when ingested. Still, some populations of corn rootworms in the U.S. Corn Belt have adapted to these toxins. We wanted to determine the level of Bt resistance to single and multiple Bt corn toxins in several field populations of NCR and WCR in eastern North Dakota (ND). Adult beetles were collected and their offspring were subjected to single-plant bioassays to screen for potential resistance to three Bt toxins (i.e., Cry3Bb1, Cry34/35Ab1, and pyramided Cry3Bb1 + Cry34/35Ab1). We present the first documented cases of field-evolved resistance in NCR to these Bt toxins as well as resistance in WCR in North Dakota. These findings indicate that field-evolved resistance to Bt toxins is occurring in some North Dakota populations of NCR and WCR.

Technical Abstract: Northern, Diabrotica barberi Smith & Lawrence, and western, D. virgifera virgifera LeConte, corn rootworms (Coleoptera: Chrysomelidae) are major economic pests of corn, Zea mays L., in North America. Corn hybrids expressing Bacillus thuringiensis Berliner (Bt) toxins are commonly used by growers to manage these pests. Many cases of field-evolved resistance to insecticidal proteins expressed by Bt corn hybrids have been documented, but only for D. v. virgifera populations. In 2016, corn rootworm beetles of both species were collected from five eastern North Dakota corn fields and reared in a growth chamber. In 2017, larvae reared from those populations were subjected to single-plant bioassays to screen for potential resistance to three Bt toxins (i.e., Cry3Bb1, Cry34/35Ab1, and pyramided Cry3Bb1 + Cry34/35Ab1). Our results demonstrated the first documented cases of field-evolved resistance in D. barberi (Arthur population) to Cry3Bb1 and Cry34/35Ab1 [Arthur, Page (documented problem area), Ransom, and Sargent populations]. Resistance to Cry3Bb1 was observed in the Ransom population of D. v. virgifera. Increased larval survival on the pyramided Cry3Bb1 + Cry34/35Ab1 hybrid was observed in both species. For D. barberi, cross-resistance between Cry3Bb1 and Cry34/35Ab1 was not evident; however, a positive correlation was found between sensitivity to Cry3Bb1 and the pyramided toxins. These findings indicate that field-evolved resistance to Bt toxins is occurring in some North Dakota populations of D. barberi and D. v. virgifera.