Susceptibility of the beet armyworm Spodoptera exigua (Hübner) to insecticides in Wakayama

Abstract

Susceptibility of beet armyworm Spodoptera exigua (Hübner) from watermelon to insecticides in Wakayama was determined in the 2nd instar larvae using the leaf dipping method. Spinetoram, spinosad, lepimectin, emamectin, and chlorfenapyr were effective on the 1st day after treatment, whereas pyridalyl and chromafenozide were effective on the 5th day after treatment. Toxicities of emamectin, pyridalyl, and chromafenozide in the Inami population were lower than those in the Gobo population.