Dry matter, energy and nitrogen conversion by Lepidoptera and Hymenoptera larvae fed leaves of black cherry

Dry matter, energy and nitrogen budgets of the form: ingestion=growth+feces+respiration, were determined for larvae of 34 species of Hymenoptera and Lepidoptera collected from and fed leaves of black cherry (Prunus serotina). The mean growth efficiencies based on energy were: gross (100 growth/ingestion)= 17±4, and net (100 growth/(ingestion-feces))=44±8. The mean nitrogen conversion efficiency was 42±10%. Correlation analysis of the relationships among larval factors (larval nitrogen content, energy equivalents, and size), leaf factors (leaf nitrogen, energy, and water content) and larval growth rates or growth efficiencies suggest that the species are temporally adapted, compensating for the limiting effects of decreasing nitrogen and leaf water as leaves mature.