Efficacy of Selected Microbial and Related Insecticides Against Fifth Instar Beet Armyworm Larvae, Summer, California, 1985

The materials were applied to individual 4-wk-old chrysanthemum plants, cv. Hurricane, with a 1-gaI B&G sprayer at 60 psi 15 Aug. Five fifth-stage larvae were immediately placed on each plant and confined with an inverted, ventilated 1 qt plastic container. Mortality was assessed after 48 h and each surviving larva was placed individually on untreated commercial beet armyworm diet. Mortality was assessed every 48 h thereafter until all surviving larvae had pupated. To correct for differences in escaping larvae between treatments, the data were expressed as percent mortality for each replicate. Arcsin square root transformations were performed on the data prior to ANOVA.