This is the first comprehensive publication on the moths of Bhutan. It treats 1966 species and illustrates 1493 of these in colour, together with 56 genital structures, on 196 colour plates. Of these, 512 are only known from literature records, and another 745 are only known from observations published in this book. Material was collected from 152 localities.
Large areas of Bhutan remain unstudied and for most regions data are only available from part of the season. Taking into consideration the number of species known from surrounding regions such as Nepal, Tibet, and the Indian states of West Bengal, Assam, Meghalaya, Arunachal Pradesh, and Sikkim, a likely estimate for the total number of Lepidoptera (butterflies and moths) present in Bhutan is between 4,000 and 5,000 species.
The collected material has been mounted by the first author and was, where needed, sent to other specialists for identification. The material is stores at the national reference collection at the National Biodiversity Centre (NBC) in Serbithang, Bhutan, with a subset of the material available for further study at Naturalis Biodiversity Center (RMNH) in Leiden, the Netherlands.