A Simple Method for Testing Spider Mite Susceptibility to Acaricides Using Body Fluid Stains in an Envelope

Abstract

In order to establish a method for testing spider mite susceptibility to acaricides that can be performed easily in agricultural extension centers or field conditions, we devised a method and determined its usability by utilizing body fluid stains of spider mites crushed in an envelope, hence the “Envelope Method”. We examined the relationship between the mortality in the envelope method, which was tested by counting stains of living spider mites and mortality in the conventional spray method. There was a trend for mortality in the envelope method to be lower compared to the conventional method. However both methods were positively correlated. Furthermore, since traces of body fluids of adult female spider mites are easily confirmed by unaided eyes, use of equipment such as a loupe is not necessary in most cases. From these observations, the envelope method was suggested as a simple and efficient method in testing the susceptibility of spider mites to acaricides at agricultural extension centers or field conditions.