Effects of Gradually Decreased Temperature on Pre- Adult Development, Adult Emergence, Sex Ratio and Weight of Pimpla turionellae (Hymenoptera: Ichneumonidae)

The effects of gradually decreased temperature on pre-adult development of endoparasitoid Pimplaturionellae (Hymenoptera: Ichneumonidae) reared on Galleria mellonella (Lepidoptera: Pyralidae) pupae atlaboratory conditions were investigated. Parasitized host pupae were acclimated at a gradually decreasedtemperature; for 3 days at each 25, 20, 15 and 10°C, and then kept in separate four groups for 2, 3, 4 and 5days at 4°C. Pre- adult development time, adult emergence, sex ratio and weight of wasps were determinedfor each treatment. Adult emergence of treatment groups lasted longer than controls for both sex and thattime was observed to increase approximately 50% in the adult from experimental group which was kept for5 days at 4°C. Adult emergence ratio also decreased by increasing acclimation time at 4°C. While ratio ofadult emergence of female was equal with that of male in the control group, that of female was found to bemore than that of adult male by increasing acclimation time at 4°C. The weight of females decreased whilethere was no difference in that of males. However, the data showed that any difference wasn’t staticallydetermined between the weigh of the control and experimental groups.