Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: PEST BIOLOGY, ECOLOGY, AND INTEGRATED PEST MANAGEMENT FOR SUSTAINABLE AGRICULTURE Title: Baseline Susceptibility of Western Corn Rootworm (Coleoptera: Chrysomelidae) to Clothianidin

Authors
item Magalhaes, Leonardo - UNIVERSITY OF NEBRASKA
item French, Bryan
item Hunt, Thomas - UNIVERSITY OF NEBRASKA
item Siegfried, Blair - UNIVERSITY OF NEBRASKA

Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 3, 2007
Publication Date: May 1, 2007
Citation: Magalhaes, L.C., French, B.W., Hunt, T.E., Siegfried, B.D. 2007. Baseline Susceptibility of Western Corn Rootworm (Coleoptera: Chrysomelidae) to Clothianidin. Journal of Applied Entomology. 131(4), 251-255.

Interpretive Summary: Western corn rootworm larval susceptibility to clothianidin, a highly effective contact and systemic neonicotinoid insecticide, was determined from both laboratory and field collected populations. Neonates were exposed to filter paper treated with increasing clothianidin concentrations and mortality was evaluated after 24 h. Additionally, two populations were exposed to artificial diet which was surface treated with clothianidin. Although larvae were more sensitive to treated diet, results with treated filter paper were more reliable in terms of control mortality and required less manipulation of rootworm larvae. Therefore, initial baseline comparisons were conducted using the filter paper assays. The variation among populations exposed to treated filter paper was generally low among laboratory populations tested, however there was a large difference in susceptibility among all populations tested. In general, clothianidin was very toxic to rootworm larvae. These results indicate the practicability and sensitivity of the paper filter disc assay to establish baseline susceptibility levels, which is an essential first step in resistance management. A baseline response provides a reference for tracking shifts in susceptibility following commercialization of a control agent so that early changes in susceptibility can be detected.

Technical Abstract: Western corn rootworm, Diabrotica virgifera virgifera LeConte, neonate susceptibility to clothianidin, a highly effective contact and systemic neonicotinoid insecticide, was determined from both laboratory and field collected populations. Neonates were exposed to filter paper treated with increasing clothianidin concentrations and mortality was evaluated after 24 h. Additionally, two populations were exposed to artificial diet which was surface treated with clothianidin. Although larvae were 5-6 fold more sensitive to treated diet, results with treated filter paper were more reliable in terms of control mortality and required much less manipulation of rootworm larvae. Therefore, initial baseline comparisons were conducted using the filter paper assays. The variation among populations exposed to treated filter paper was generally low, (4.4-fold) among laboratory populations tested, however there was a 14.5-fold difference in susceptibility among all populations tested. In general, clothianidin was very toxic to rootworm neonates, with LC50s ranging from 1.5 to 21.9 ng/cm2. These results indicate the practicability and sensitivity of the paper filter disc assay to establish baseline susceptibility levels, which is an essential first step in resistance management. A baseline response provides a reference for tracking shifts in susceptibility following commercialization of a control agent so that early changes in susceptibility can be detected.

Last Modified: 12/21/2014