Parasitism preference of normal and irradiated host pupae of Bactrocera zonata, Saunders (Tephritidae: Diptera) and Bactrocera cucurbitae, Coquillett (Diptera: Tephritidae) by pupal parasitoid, Dirhinus giffardii, Silvestri (Chalcididae: Hymenoptera)

Fruit flies of the genus, Bactrocera are destructive pests of fruits and vegetables. A number of insecticides are applied for their control which are a serious threat to the environment and human health. Awareness is now developing among the farmers towards more sustainable and environmentally safe management practices. In our present study parasitism potential of Dirhinus giffardii and effect of irradiation on host pupae emergence time was investigated. The results showed that maximum parasitism of 40.35 in free choice and 47.30 percent in the no choice test for pupae of Bactrocera zonata and 37.75 in free choice and 35.15 percent in no choice for the pupae of B. cucurbitae, respectively. Maximum parasitism of 58.4 percent was recorded on three day old pupae irradiated with 40 Gy dose. Moreover, D. giffardii emergence from parasitized irradiated pupae, sex ratio were slightly tilted in favor of female with maximum female ratio of 1.22: 1 and 1.19: 1 was observed on 60 Gy dose on B. zonata and B. cucurbitae respectively . On the basis of experimental results it is concluded that D. giffardii can effectively be used to control B. zonata and B. cucurbitae and irradiation could effectively be used to increase emergence time of the host pupae.