Selection of the Multiple-Resistant Green Rice Leafhopper, Nephotettix cincticeps UHLER (Hemiptera : Deltocephalidae) with Propaphos : Reversion of Resistance to Propoxur

抄録

Selection of an organophosphorus- and carbamate-resistant strain of the green rice leafhopper with di-n-propyl organophosphate propaphos, an inhibitor of the modified acetylcholinesterase in this insect, resulted in a decrease in the level of esistance to propoxur, although it multiplied the resistance to propaphos, diazinon and pyridafenthion. The results of sensitivity of acetylcholinesterase to inhibitors suggested that the decrease in the resistance to propoxur was mainly attributed to a change in the ratio of two different enzymes, i.e., normal and modified acetylcholinesterases. On the contrary, the increase of resistance to propaphos, diazinon and pyridafenthion seemed to be related to another factor.