Population dynamics of pod fly, Melanagromyza obtuse (Malloch) and its natural enemies on pigeonpea

Abstract

On pigeon pea pod fly infestation often noticed in the Kharif crop during 2022-23 and 2023-24, along with its other defoliating insects, although it persists up until the crop has been harvested. First appearance of M. obtusa larvae and pupa was observed in the 41st and 39th meteorological standard week (MSW). The peak larval population of 52.00 and 41.00 larvae per 100 pods was noticed in the 44th MSW at both years, while the peak pupal population of 49.00 and 40.00 pupae per 100 pods was seen during the 50^th and 45th MSW. The study showed presence of two hymenopteran parasitoids viz., Euderus lividus (Ashmead) and Ormyrus orientalis (Walker) on the pigeon pea major pest, Melanagromyza obtuse (Malloch). The parasitism level of E. lividus declined from 31.82 to 10.53 and 29.72 to 7.14 per cent from 46^th up to 52nd MSW and 45th up to 50th MSW, respectively. Higher pupal parasitism of O. orientalis was recorded in 47th (25.64%) and 44th (24.32%) MSW; While low parasitism was noted in 1st (3.22%) and 51^st (3.84%) MSW at both years. Above all, correlation between weather parameters, with pod fly larvae and pupae showed that the larval population exhibited a significant positive relation with maximum temperature (r=0.646*) and (r=0.746**) at both years. The natural enemies, E. lividus and O. orientalis of M. obtuse, would improve the biological control of the pest population.