INTRODUCTION

Arthropods, along with other invertebrates, make up 95% of the global fauna, with 1.5 million described species and at least a further 6 million that remain undescribed. These organisms, which include insects, arachnids and myriapods, play a significant role in the life histories of a range of primate species, not least in their diet. Body size plays an important part in determining the degree of insectivory (Kay, 1984); however, an example of insect eating can be found within all lineages of the primate phylogeny. Prosimians have long been described as insectivores, some having morphological adaptations for insect feeding (e.g. the extractive finger of the aye-aye, Daubentonia madagascariensis) and others adopting behaviours such as aerial snatching (e.g. galagos, Galago demidovii), or stalking specific arthropod prey (e.g. angwantibos, Arctocebus calabarensis) (Charles-Dominique, 1974). Some Loridae, like the potto (Perodicticus potto), have evolved specialised diets in which the arthropod prey emit distasteful chemicals (e.g. formic acid from ants: Crematogaster spp.) or have the potential to inject venom (e.g. large scolopendrid centipede: Spirostreptus spp.) (Charles-Dominique, 1974). Chimpanzees (Pan troglodytes) use tools to help to eat insects such as bees (Apis spp.), and the honey they produce (Tutin & Fernandez, 1992). Even folivores that appear to be entirely vegetarian inadvertently eat thousands of insects a day (e.g. mountain gorillas, Gorilla gorilla beringei, and langurs, Semnopithecus entellus).