Natural and - Induced Variations in Two-Spotted Spider Mite Populations

Abstract

Rather marked differences were observed in the reaction of Tetranychus bimaculatus to acaracides when the mites were feeding on different hosts. When the mites were transferred from one host to another their characteristic behavior on the original host was maintained for a brief period but gradually disappeared. On a given host, resistance to the action of 2 acaracides was gradually built up over a period of 3 mos. by repeated applications of dilute preparations of each of the acaracides.