Data and analyses from pilot studies in the Danum area of Sabah, East Malaysia, and elsewhere in the Indo-Australian tropics are used to measure the effects of logging and other human disturbance, such as conversion to plantation, on insect diversity. The two insect groups studied have very different trophic requirements: moths, with floristically specific herbivory, and dung and carrion beetles, exploiting resources of much more uniform quality over different forest systems. Moths show significant loss of diversity and taxonomic quality with disturbance and conversion to plantation. The beetles show much less change in diversity and faunistic composition. The implications for conservation of biodiversity are discussed, and suggestions for further work are made.