THE EFFECT OF COLD-STRESS ON BIOCHEMICAL COMPONENTS OF THE LARVAL FAT BODY, HAEMOLYMPH AND EXCRETA IN TROPICAL TASAR SILKWORM, Antheraea mylitta Drury (LEPIDOPTERA: SATURNIIDAE)

Studies on cold acclimation of insects including s ilkworms have shown significant variations in the levels of various biomolecules to cope with thermal shock. The present study has been carried out on cold-stressed larvae of Daba Trivoltine (TV) of tasar silkworm, Antheraea mylitta Drury to analyze the mortality rate, variations in the biomolecules and excretory products at varied durations. The results revealed that exposure to low temperatures (10±1oC) for seven days leads to 100% mortality, five days exposure caused 50% mortality and two days exposure resulted in 38% mortality on reverting the larvae to normal temperature. The treatment of Daba T.V larvae with low temperatures resulted in increased aminoacid content (2% – 5%) in the haemolymph and decreased in fat body (37% – 94%) of all the three treatments in comparison with control group reared at 28±2oC. Significant decrease in urea (68% – 77%) and uric acid (46% 50%) was observed in the larvae exposed to cold stress in comparison with control group.