Relative Susceptibility of Red and Gree Color Morphs of the Green Peach Aphid to Foliar and Systemic Insecticides

Abstract

Foliar and systemic insecticide bioassay techniques were developed for testing insecticide susceptibility to two color morphs of the green peach aphid. Six foliar and one systemic insecticide were used in our evaluations. These insecticides included three organophosphates, two pyrethroids, one organochlorine, and one chloronicotinyl. One of the green colored populations tested was collected from spinach, and red and green color populations were collected from the within the same cabbage field. The red morph was found to be less susceptiblethan the green morphs to Dimethoate, Karate, and Endosulfan. Their were only slight differences in susceptibility to the foliar insecticide between the green morphs. The greenmorph from spinach was found to be the most susceptible to Admire, while the two morphs collected from cabbage did not differ. Leveling off of aphid mortality at about 85% with high doses of Admire may indicate highly tolerant types in the populations, or an artifact of the methodology.