Consumption and utilization of various host plants by Melanoplus bivittatus (Say) and M. femurrubrum (DeGeer) (Orthoptera: Acrididae)

Abstract

Nymphal stages of Melanoplus bivittatus (Say) and M. femurrubrum (DeGeer) that were reared on five plant diets fed and grew at different rates. Differential mortality was obtained among the two species reared on the various diets, with the highest occurring in those feeding on alfalfa. On all plants a direct linear relationship was obtained between rate of food consumption and rate of growth, and slopes varied from 0.18 to 0.25 in M. bivittatus and from 0.14 to 0.18 in M. femurrubrum. The approximate digestibility on the various plants were all in the range of 41 to 47% for M. bivittatus and 37 to 48% for M. femurrubrum. The efficiency of conversion of digested food to body tissue (ECD) varied from 35 to 44% in M. bivittatus and from 33 to 44% in M. femurrubrum. The efficiency of conversion of ingested food to body tissue (ECI) varied from 15 to 18% in M. bivittatus, and from 15 to 19% in M. femurrubrum. Egg production in M. bivittatus varied from 196 on corn to 450 on radish; it was lower in M. femurrubrum, and varied from 162 on corn to 336 on the mixed diet.