The Effect of Certain Insecticides and Fungicides on Fungi Pathogenic to the Spotted Alfalfa Aphid1

Abstract

Laboratory tests have shown that certain insecticides and Fungicides are toxic to the vegetative stages of some of the fungi that attack the spotted alfalfa aphid, Therioaphis maculata (Buckton). Most susceptible to these materials was Entomophthora exitialis Hall & Dunn, the dominant pathogen of the aphid in California. Further tests have indicated that the insecticides do not kill the resting spores of E. virulenta H. & D. although germination is retarded to some extent.