Bornean caterpillar (Lepidoptera) constructs cocoon from Vatica rassak (Dipterocarpaceae) resin containing multiple deterrent compounds.

Many Lepidoptera larvae use pieces of vegetation bound with silk to construct or disguise their cocoons. Here we report the first known case of a caterpillar building its cocoon entirely out of fragments of resin, broken away from sheets of dried resin on the trunk of a tree and held together with silk. The behaviour of the larva (possiblyNegritothripasp. in the Nolidae), from the Kinabatangan Wildlife Sanctuary in Sabah, Borneo, is described. The cocoon was constructed on the trunk ofVatica rassak(Dipterocarpaceae). Analysis of resin from the cocoon, using gas chromatography-mass spectrometry, revealed a complex mixture of 260 components, dominated by sesquiterpenes and triterpenes. Many of these compounds have defensive properties, protecting the tree from herbivores and fungi. The larva appears to have evolved an elaborate and possibly unique behaviour, allowing it to harness the defensive properties of the resin to protect its pupa from predators and/or entomopathogenic fungi. [ABSTRACT FROM AUTHOR]