Prey composition of the pitcher plant Nepenthes madagascariensis

Nepenthes madagascariensis is a carnivorous plant which captures its prey in pitcher-like leaves. It is endemic to Madagascar where it occurs along the eastern coast. Altogether 94.3% of its prey animals belong to three taxa: Formicidae (80.2%), Diptera (9.7%) and Coleoptera (4.4%). The prey compositions of the dimorphic lower and upper pitcher types differ significantly, especially in the markedly higher proportion of ants in lower pitchers and the higher number of flying insects in upper pitchers. A comparison concerning the trap frequency of taxa with literature data from Asian Nepenthes species showed that the upper pitchers of N. madagascariensis contained much higher proportions of Coleoptera, Diptera and Lepidoptera; these differences may partly be due to seasonal reasons. No significant correlation could be established between the numbers of prey items with pitcher size. This paper is the first characterization of the prey composition of the little known N. madagascariensis.