Assessment of Insecticide Susceptibility of Liriomyza sativae (Diptera: Agromyzidae) by Topical and Residue Bioassays

Abstract

A residue technique for assessing insecticide susceptibility of the vegetable leafminer, Liriomyza sativae Blanchard, was developed. When the residue method and a previously described topical application technique were compared, the two methods had the same degree of variability in LC50’s and slopes of the probit regression lines. Relative toxicity of permethrin to two leafminer populations was different for the topical and residue tests. A significant difference in susceptibility for two populations was obtained with the residue technique, but no significant difference was obtained with the topical technique. The residue technique required less labor, yielded lower control mortalities, and was more representative of the situation found in the field.