Exposure Time and age Links Parasitism, Emergence and Development of Pupal Parasitoid Dirhinus giffardii Against Bactrocera zonata

Abstract

The parasitism, emergence and development of pupal parasitoid, Dirhinus giffardii (Silvestri) was assessed against the pupae of the fruit fly, Bactrocera zonata (Saunders), under laboratory conditions. The fruit fly and D. giffardii were reared in glass cages on the artificial diet, and a known number of different 1-hour (fresh), 1-day, 2-day, 3-day and 4-day old pupae were offered to the respective parasitoids for a period of 6, 12, 18 and 24 hours. It was noted that the parasitism was increased gradually with an increase in pupal age and exposure time. The highest parasitism occurred on 3-day old pupae followed by 4-day, 2-day, 1-day and 1 hour (fresh) old pupae. The studies also manifested that exposure time and host age have a significant effect on the oviposition, per female parasitism, percent parasitism, emergence and development of pupal parasitoid, D. giffardii. The average developmental time of parasitoid was recorded significantly longer in 1-hour (fresh) old pupae than in the older pupae. The study revealed that D. giffardii is a virtuous candidate for the biological control of B. zonata and the pupae of B. zonata might be the perfect host for laboratory rearing of this parasitoid.