Entomopathogens coming in contact with the host invade cuticle and enter the haemocoel; there interaction between the pathogen and immunocytes (Plasmatocytes and Granulocytes) takes place. This book describes this process taking Beauveria bassisna as the pathogen and the rice hispa, Dicladispa armigera (Coleoptera : Chrysomelidae) as the host. The book is going to benefit students, researchers and teachers of immunology and entomology.