Location: Integrated Cropping Systems Research
Title: Effect of transgenic corn hybrids and a soil insecticide on corn rootworm (Coleoptera: Chrysomelidae) beetle emergence in North DakotaAuthor
TORREZ, VERONICA - North Dakota State University | |
KNODAL, JANET - North Dakota State University | |
BOETEL, MARK - North Dakota State University | |
French, Bryan | |
FULLER, BILLY - South Dakota State University | |
RANSOM, JOEL - North Dakota State University |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 1/19/2016 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Northern, Diabrotica barberi Smith & Lawrence, and western corn rootworms, D. virgifera virgifera LeConte, are economic pests of corn, Zea mays L. (Poaceae) in North Dakota. Many area corn growers rely on transgenic Bt (Bacillus thuringiensis) corn hybrids to manage corn rootworms. Our objective was to determine the impacts of corn hybrids expressing Bt proteins and a soil insecticide (tefluthrin) on emergence of Diabrotica adults in North Dakota. Emergence trapping was conducted at five locations in southeastern North Dakota from 2013 to 2015. Three hybrids expressing the following Bt proteins were tested: Cry3Bb1, Cry34/35Ab1, and pyramided Cry3Bb1 + Cry34/35Ab1. No significant interactions occurred between hybrid and soil insecticide at any location. Emergence of D. barberi was significantly lower in all Bt treatments than in non-Bt treatments. The highest number of D. v. virgifera adults emerged from the Cry3Bb1 treatment, and it was even higher than that from non-Bt treatments at one location. Adult emergence of D. v. virgifera was significantly lower in Cry34/35Ab1 and Cry3Bb1 + Cry34/35Ab1 treatments than in non-Bt treatments. The lowest adult emergence was observed in Cry3Bb1 + Cry34/35Ab1 plots, regardless of Diabrotica species or location. Across all locations and both species, there were no significant differences in beetle emergence from soil insecticide plots and those not treated with soil insecticide. However, significantly lower numbers of beetles emerged from all Bt treatments when compared to soil insecticide treatments, thus indicating that the soil insecticide did not increase control over that of the Bt treatments. |