The tobacco caterpillar, Spodoptera litura (Fabricius) is regular polyphagous pest of field and horticultural crops and is distributed throughout Asia, from North Africa to Japan, Australia and New Zealand the eastern part of the world.It infests more than 112 crop plants belonging to 44 families in the world, of which 40 cultivated plants as well as 24 wild plants are known from India.This pest has become devastating because of its features such as polyphagous nature, high reproductive potential, overlapping generations, year round availability of host plants, ability of adults to migrate over large distances and frequent control failures with most of the routinely used insecticides.As a result of excessive selection pressure exerted by the intensive use of insecticides, field populations of S. litura has become resistant to most of the insecticides. Development of insecticide resistance in S. litura is one of the major obstacles for the profitable cultivation of vegetables and commercial crops. Therefore this book is intended for the PG students and researchers of Toxicology, Entomology and Enviromenatal sciences.