Water, energy and nitrogen utilization by larvae of five species of Lepidoptera feeding on prunus serotina leaves

Abstract

Dry mass, energy, nitrogen and water budgets were determined for five species of lepidopteran larvae fed on freshly collected Prunus serotine leaves. Significant interspecific differences were found for all efficiencies of utilization with the exception of gross nitrogen utilization efficiency. Net efficiency of energy utilization correlated only with gross nitrogen utilization efficiency and with rate of production of metabolic water. Gross nitrogen utilization efficiency correlated positively with rate of growth and with water availability and negatively with both gross and net water utilization efficiencies. It was hypothesized that energy efficiencies are limited by genetically controlled, interspecific, adaptive differences while nitrogen efficiency is limited by environmental factors more universally applicable according to life strategy. It was also suggested that the observed data were consistent with the hypothesis of energy efficiency maximization.