DIFFERENCE IN WEIGHT GAIN DURING FINAL STADIUM OF PALE WESTERN AND ARMY CUTWORMS RELATED TO LIFE HISTORY AND CROP DAMAGE

Abstract

AbstractWeight gain during the penultimate and ultimate stadia of the pale western cutworm, Agrotis orthogonia Morr., comprises about 37% and 39%, respectively, of the maximum larval weight. For the army cutworm, Euxoa auxiliaris (Grt.), the corresponding values are 20% and 69%. The proportion of final larval weight that is gained by the ultimate-instar larva of the army cutworm is similar to that reported for other noctuids, whereas the proportion gained by the ultimate-instar larva of the pale western cutworm is much lower and is likely related to the prepupal aestivation that occurs in this species. Because of the growth pattern of pale western cutworm, a substantial proportion of total food consumption, and consequently, crop damage, occurs during the penultimate stadium of this species.