Crop losses are caused by a variety of living organisms that feed, parasites and compete with the crop plants. In man made agriculture, loss from insect pests is very high. In India, annual crop losses are estimated at Rs 6,000 to 7,000 crores. Of this, loss from insects and rodents alone is 26 per cent. Minimizing avoidable losses is one way of enhancing food grain production.This course gives basic information regarding the management of harmful insects in crop production. Biological measures of pest control have also been discussed sufficiently in this course.