Evaluation of etoxazole against insects and acari in vegetables in China.

Yongqiang Li,Qingmin Wang,Xinling Yang,Xingcun Wei,Na Yang,Yun Ling

doi:10.1673/031.014.104

Abstract

Etoxazole, 2-(2,6-difluorophenyl-4-[4-(1,1-dimethylethyl)-2-ethoxy-phenyl]-4,5-dihydrooxazole, an organofluorine chitin synthesis inhibitor, was assayed for its bioactivities against several major insect and acarus pests and compared to several other pesticides: two chitin synthesis inhibitors, hexaflumuron and chlorfluazuron; a pyrethroid, permethrin; an organophosphate, acephate; a carboximide, hexythiazox; and a tetrazine, clofentezine. The LC50 of etoxazole was calculated using probit analysis of the concentration-dependent mortality data against susceptible and resistant strains of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae); diamondback moth, Plutella xylostella L. (Plutellidae); bean aphid, Aphis craccivora Koch (Hemiptera: Aphididae); and carmine spider mite, Tetranychus cinnabarinus (Boisduval) Boudreaux (Trombidiformes: Tetranychidae). The resistant strains were found to be resistant against all tested pesticides except etoxazole. The bioactivity of etoxazole was many times that of the other tested insecticides and acaricides widely used in vegetable crops in China. On the basis of our research, etoxazole can be expected to be extensively used on vegetable crops in China.

Highlights

Vegetables are a leading economic crop, and insects and acari have important impacts on yield and quality
The toxicity of chemical insecticides and acaricides is a primary drawback, as they are a hazard to the environment, human health, and beneficial organisms
We report on the bioactivity of etoxazole against these insects and spider mites and compare the results with those of several pesticides

Summary

Introduction

Vegetables are a leading economic crop, and insects and acari have important impacts on yield and quality. Many new physical and biological control methods have been developed that favor the environment and beneficial organisms, such as biological control organisms, organic insecticides, and physical and horticultural activities. Due to restrictions imposed on agricultural and economic development, developing and applying new chemical insecticides and acaricides are still major measures for coping with insect and acari damage in vegetable production systems in China. The toxicity of chemical insecticides and acaricides is a primary drawback, as they are a hazard to the environment, human health, and beneficial organisms. Insect growth regulators are designed and synthesized to take advantage of unique aspects of development compared to other organisms (Verloop et al 1977; Oberlander et al 1998), which makes them safe to nontargets, highly friendly to the environment, and selective for insects and acari. IGRs have been developed in recent years by researchers throughout the world (Qian 1996; Yang et al 1999)

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