Influence of Resistant and Susceptible Pigeonpea Cultivars on the Parasitization Efficiency of some Parasitoids on Podfly, Melanagromyza obtusa (Malloch)

Three parasitoids, viz. Ormyrus orientalis Walker, Euderus agromyzae Gangrade and Eurytoma ranjithi Narendran were found parasitzing podfly, Melanagromza obtusa (Malloch) on all the three cultivars of pigeonpea. Parasitization increased with the increase in pest population irrespective of the parasitoid species. Ormyrus orientalis was recorded as the key parasitoid. There was a significant effect of resistant and susceptible varieties on parasitization of podfly. The mean parasitization by all the three species in 2000-01 was 24.0 per cent on NA1 followed by Bahar (22.5%) and SL12-1 (8.4%). Similarly, in the following year, the mean parasitization was 25.0 per cent on NA1 which was on par with Bahar (24.3%) but significantly superior (p=0.05) to SL12-1 (9.3%). A distinct variation in the population of pest, Melanagromyza obtusa with respect to pigeonpea cultivars was observed, however, the oviposition trend recorded at weekly interval was found almost same. The average oviposition was 14-15 per cent in case of the susceptible varieties (Bahar and NA1) whereas; the resistant variety SL12-1 exhibited only 4 per cent oviposition by podfly. The results clearly indicated that greater parasitism of M. obtusa occurred on susceptible genotypes than resistant cultivar.