Comparison of Methods of Infesting Whorl-Stage Corn with Fall Armyworm Larvae123

Abstract

In tests comparing the effectiveness of 3 methods of infesting whorl-stage corn with Spodoptera frugiperda (J. E. Smith), the modified “Bazooka” proved to be the best method based on resultant visual damage ratings. The “Bazooka” is a device made primarily of Plexiglas, and larvae of fall armyworms can be mechanically dispensed into whorls of corn plants. It was easier and more efficient than using the camel-hair brush or pinning egg masses into the whorl. Infestation of every plant per plot produced higher leaf-damage ratings than infestation of either every 2nd or every 3rd plant/plot. Differences in leafdamage ratings were detected at infestation rates of 10, 20 and 40 larvae/plant. Rates of 20 or 40 larvae/plant should be used to insure adequate infestations at the 10–12 leaf stage.