The impact of actual and surrogate variegated cutworm stubble phytophagy on the growth and yield of alfalfa

Abstract

Variegated cutworm, Peridroma saucia (Hiibner), consumption and development on alfalfa was studied in the laboratory. Larvae exhibited either six or seven molts. Larvae with six molts required 35.6 ± 7.1 days (±SD) for development and consumed 352.6 ± 67.5 mg of foliage. Development and consumption by larvae with seven molts were 32.8 ± 3.7 days and 442.2 ± 57.9 mg of foliage, respectively. Larval and adult dry weights indicated that larvae exhibiting seven molts probably were repre sentative of feral individuals. Consequently, data from these larvae were used to develop an alfalfa-consumption model for the variegated cutworm.