NUTRITION OF THE PALE WESTERN CUTWORM, AGROTIS ORTHOGONIA MORR. (LEPIDOPTERA:NOCTUIDAE): III. LYOPHILIZED SPROUTS AND LEAVES OF WHEAT AS A BASAL DIET FOR LARVAE, AND EFFECTS OF SUPPLEMENTATION WITH L-LEUCINE

Abstract

The pale western cutworm, Agrotis orthogonia Morr., was reared from egg to adult in the laboratory when supplied with diets prepared from etiolated sprouts or 10-day-old leaves of Thatcher wheat that had been lyophilized, ground, and made up to 66.7% moisture content. A diet that contained 33.3% lyophilized, 10-day-old Thatcher leaf and 66.7% water was inferior to one containing equal parts of wheat leaf and cellulose powder with the same moisture content. Although larvae fed a diet with 25% leaf tissue and 75% cellulose powder, on a dry-weight basis, developed more slowly and were smaller than those fed higher concentrations of leaf, some matured and emerged as adults. When the 25% leaf diet was supplemented with 14.3 mg of L-leucine per gram all the larvae died during the first two instars. Addition of this quantity of L-leucine to either the 50% leaf or the lyophilized sprout diets did not have such an effect. These results were interpreted as being due to an amino acid imbalance which, as with the rat, becomes apparent only on a suboptimal diet.