Euproctis latifascia Walker is an important pest attacking old leaves of tea bushes and mother leaves of nursery cuttings in Darjeeling foothills, Terai and Northeast India. Laboratory experiments were designed to assess the effect of an artificial diet and a natural diet, i.e. tea leaves, Camellia sinensis, on life history traits like development time, survival and fecundity of E. latifascia. In addition, the maintenance cost as well as the nutritional and production indices were estimated for each substrate (diet) using the gravimetric (dry mass) methods. On the natural (tea leaves) and artificial diets, the total development periods were 78.4 and 68.6 days, fecundity 248.8 and 230.3 eggs/female; in the final caterpillar stage (VI), the relative consumption rates were 0.8 and 0.6, relative growth rates 0.05 and 0.07, maintenance costs 5.1 and 2.9 and production index 0.1 and 0.2, respectively. The fifth instar larvae also showed similar differences in their nutritional indices. Based on these parameters it appears that the artificial diet is more suitable for laboratory rearing of E. latifascia than the natural tea-leaf diet.