Biological notes on herbivorous insects feeding on myrmecophytic Macaranga trees in the Lambir Hills National Park, Borneo

Abstract

Myrmecophytes are plants that harbor ant colonies in domatia, which are hollows in the plant body. Most ant species that colonize myrmecophytes aggressively attack and regulate the abundances of herbivorous insects that would otherwise feed on the leaves of host trees. Although previous studies have described the interactions between myrmecophytes and herbivorous insects, a large proportion of herbivores that are able to feed on these trees are still unrecorded and details of their feeding habits are largely unexplored. Here, we compile biological notes on some of the herbivorous insects that feed on several species of Macaranga (Euphorbiaceae) growing in the Malayan archipelago, including those that are myrmecophytic. The information assembled here is based on our field observations, sampling, and rearing of insects, which we have conducted since 1994 in the tropical lowland forest of the Lambir Hills National Park, Sarawak, in Malaysian Borneo. We also summarize existing published information. For the convenience of future studies of herbivores that feed on Macaranga, we have included a large selection of images to show the morphologies and ecological traits of herbivores, including their structures at different growth stages and the marks made by their activities, such as leaf-chewing, leaf-mining, and gall formation. Among the herbivorous insects that feed on Macaranga species, we focus on butterflies, phasmids, gall midges, and myrmecophilous bugs.