Trophic ecology of Lepidoptera larvae associated with woody vegetation in a savanna ecosystem

Abstract

This study represents a quantitative survey of a Lepidoptera community and deals with the trophic ecology of the 27 species of foliage-feeding Lepidoptera on the eight dominant woody plants in the Burkea africana-Eragrostis pallens savanna at Nylsvley. Food intake, growth and excretion by the eight dominant Lepidoptera species were measured in the field and monthly field surveys of standing crop of all species were carried out. The trophic ecology of the whole Lepidoptera system was extrapolated from these results. All feeding, growth and excretion data were expressed in dry mass per ground surface area. Aspects of the biologies of the eight dominant species considered necessary to assess likely variations in the impact of foliage consumption by larvae eg number of generations per season, whether species are potentially eruptive or not, feeding techniques and specificity, are discussed. The effect of Lepidoptera larvae on the woody vegetation is discussed. Removal of plant tissue by the larvae was insignificant in terms of mass, but comparable to that in other systems.