The bionomics of the lasiocampid Malacosoma indica [M. indicum], a defoliator of temperate fruit trees, are described from field studies conducted in the Kumaon Hills, India, during April-May of 1974-77, and laboratory studies. Notes are given on the distribution of the pest in India; food plants (which included apple, peach and plum); life history; the morphology of the egg, larva, and pupa; pupation; larval and pupal mortality; adult emergence and sex ratio; courtship behaviour and copulation; oviposition; longevity of the imago; seasonal history and natural enemies (which include the egg parasitoids Telenomus sp. and Anastatus sp. nr. kashmirensis, the larval and pupal parasitoids Pales sp. and an unnamed ichneumonid, and the fungus Aspergillus flavus). none