Effects of the synergist S,S,S-tributyl phosphorotrithioate on indoxacarb toxicity and metabolism in the European corn borer, Ostrinia nubilalis (Hübner)

Analiza P. Alves, University of Nebraska - Lincoln
William J. Allgeier, University of Nebraska - Lincoln
Blair D. Siegfried, University of Nebraska - Lincoln

Document Type Article

Published in Pesticide Biochemistry and Physiology 90:1 (January 2008), pp. 26-30; doi:10.1016/j.pestbp.2007.07.005 Copyright © 2007 Elsevier Inc. Used by permission. http://www.sciencedirect.com/science/journal/00483575

Abstract

The toxicity of the oxadiazine insecticide indoxacarb to the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), was evaluated in the presence and absence of S,S,S-tributyl phosphorotrithioate (DEF), an inhibitor of hydrolytic metabolism. Bioassays involving topical application of different concentrations of indoxacarb to third instars of a susceptible O. nubilalis laboratory strain were performed, and in vitro metabolism experiments involving [¹⁴C] indoxacarb were examined to determine the role of hydrolytic metabolism in indoxacarb activation. Indoxacarb toxicity decreased in the presence of DEF indicating antagonism of toxicity. Results of in vivo and in vitro inhibition experiments indicated a reduction of indoxacarb activation and formation of the hydrolytic metabolite. These results are consistent with the proposed mechanism of hydrolytic activation for this compound.