Effect of cold storage on the survival,sex ratio and longevity of ectoparasitoid,Bracon hebetor (Say.) (Hymenoptera: Braconidae)

The ectoparasitoid,bracon hebetor (say.) (hymenoptera: braconidae) is considered one of the most important biological control agents of several pyralid (lepidoptera) pest insects. the effects of low temperature storage on the quality of adult parasitoids and their progeny were investigated by storing different life stages of the parasitoid (eggs,larvae,pupae and adult) at temperatures i.e.,4±1°c and life sages of the wasp stored at 27±1°c were acted as control (12l:12d photoperiod) for 5,10,20 and 40 days. our data reveals that number of surviving individual decreases as the storage period increases along with the rate of emergence which reduced from onward 10 days of storage and with decreasing temperature at 4°c. highest survival of 24.00±1.41 was observed during storage of adult wasp at 4°c followed by pupae (20.00±1.41),however larvae and eggs could not survive to adult stage after 40 days cold storage treatment. adult longevity decreased while sex ratio was female biased in all cases by increasing cold storage duration. therefore,it may be concluded that adult stage of b. hebetor is more cold tolerant than all other stages and considered to be more suitable for short term storage. copyright 2016 zoological society of pakistan.