Detection of resistance to pyrethroids in field populations of cotton jassid (Homoptera: Cicadellidae) from Pakistan

Toxicity of 8 pyrethroids was determined in adult populations of cotton jassid, Amrasca devastans (Distant), during 1995-1998 using a leaf-dip method. There was very low jassid resistance to alphacypermethrin, fenpropathrin, bifenthrin, lambdacyhalothrin. and etofenprox. Resistance to cypermethrin and deltamethrin was generally very low as well: but several populations did show a low to moderate level of resistance to these compounds and one population even exhibited a very high resistance to deltamethrin when the mortality was assessed after 24 h. Moderate to high resistance was found to zetacypermethrin in 6 of 8 populations tested. This development of resistance to some pyrethroids in the Pakistani populations of jassid is a serious cause for concern and it underscores the need for effective management at the initial stage of development.