Relationship between the incidence of pod infestation of Cajanus cajan (L.) Millsp. by Melanagromyza obtusa (Malloch) and the rate of parasitism*

Three hymenopterous parasitoids, viz Euderus lividus (Ashmead), Ormyrus orientalis Walker, and Eurytoma sp. attack larval and pupal stages of tur pod fly, Melanagromyza obtusa, a pest of Cajanus cajan (L.) Millsp. The appearance of these parasitoids often synchronised with the availability of the immature stages of Melanagromyza obtusa. On an early arhar variety, the studies showed that the pod infestation, generally, commenced by the end of September. But, the parasitism did not appear before the third week of October or sometimes it may be as late as in the flrst week of November at Agra. On late arhar variety, the pod infestation started in December and attained a high incidence of tur pod fly. But, no parasitism appeared in the second week of January when pod infestation by Melanagromyza obtusa was at its peak. Therefore, within certain limits, the incidence of parasitism seemed to be inversely proportional to the incidence of pod infestation.