The extensive freshly collected material available arose partly through the activities of the author under the auspices of the Royal Geographical Society -Sarawak Government Expedition and Survey of the Gunung Mulu National Park (1977-8), whilst financed by a Government Grant.in.Aid for Scientific Investigations administered by the Royal Society, and on a previous expedition (1965) to G. Kinabalu. Another large part of this material was accumulated and prepared by Col. M.G. Allen and Mr T.W. Harman during a series of expeditions in Brunei. I am grateful to Prof. Dr L.W.R. Kobes for access to the Sumatran material collected by Dr E.W. Diehl and others, the basis of the Heterocera Sumatrana Society project, which enabled additions to be made to the known distributions of several species. Similar information for Peninsular Malaysia was gained by examining the collection of Mr H.S. Barlow.

Mr Bernard D'Abrera kindly took the photographs for the colour plates of adult specimens. I am grateful to Dr M.J. Bascombe, Dr P.A.C. Ooi and Dr MJ.W. Cock for allowing me to use their colour slides of larvae for the final plate.

My thanks are due to the University Museum, Oxford, Dr R. de Jong (Rijksmuseum van Natuurlijke Historie, Leiden), Dr H.J. Hannemann (Museum fur Naturkunde der Humboldt.Universitat, Berlin), Dr T. Kumata and Dr H. Inoue for arranging loans of type material or material of species not represented in the BMNH.

The taxonomic work was undertaken at the British Museum (Natural History) with the permission of the Trustees and with the assistance and support of the Department of Entomology, particularly the Macrolepidoptera Section. I am indebted to colleagues there and worldwide for helpful comments on earlier drafts of the key to families, to Mr D.J. Carter for advice on larval characters and to Mr J.W. Schoorl and Dr W. Speidel for dis. cussions on the Cossidae. Dr MJ.W. Cock and M R. Desmier de Chenon provided additional information on limacodid biology.

My thanks are also due to Avril Fox, long suffering courier of genitalia artwork.

Finally I would like to thank my wife, Phillipa, for taking on much of the burden of preparing the typescript.