This book is about blackflies which are well known for being a biting nuisance and transmitting disease. They are considered the second most harmful group of insects after mosquitoes in affecting human health. Information about blackflies in India is scant despite their medical and veterinary importance. This monograph provides summarised and updated information on the biology, diagnosis, pest status and management of Indian blackflies. Emphasis has been put on blackflies of northeast India where they are threatening public and animal health and have negative impacts. The introductory chapters deal with the importance of blackflies in India as human and domestic animal pests and list man-biting species for the first time. Three species (S. himalayense, S. indicum and S. nodosum) are reported as highly anthropophilic. The subsequent chapters with illustrations deal with the biology, collection of blackflies and their preparation, preservation, and rearing for species diagnosis by using morphological, cytotaxonomical, and molecular characters. The use of DNA taxonomy along with morphology and ecology is emphasised for the identification of cryptic or sibling species within the species-complexes especially in species-complexes that cause medical problems. Identification keys for 73 Indian species are given for the first time. The book ends with a chapter on the lesson learnt, practical tips and future research for the study of blackflies in the country. This book is a step-by-step guide for blackfly study in this region.