Abstract
Dry matter, energy and N budgets of the form: ingestion (I) = growth (G) + respiration (R) + egestion (F) were evaluated for the larvae of D. plexippus (L.) fed Asclepias syriaca at 27.degree. C, 80-90% RH [relative humidity], 14 h light. Gross efficiencies of growth (100 G/I), 16% (dry weight), 21% (caloric equivalents) and 48% (N) are similar to the efficiencies of other lepidoptera while net efficiencies of growth (100 G/(I-F)), 35% (dry weight) and 44% (caloric equivalents), are lower. The average to low efficiencies of D. plexippus do not support the hypothesis that oligophagous lepidoptera are more efficient at utilizing their resources than polyphagous lepidoptera.