Biochemical studies of comparative haemolymph constituents in fourth instar larvae of Daba trivoltine ecorace of topical tasar silkworm Antheraea mylitta D

Diapause is endocrine mediated dormancy and the preparatory stages are fourth and fifth instar larvae of tasar silkworm, Antheraea mylitta Drury. Different haemolymph biochemical constituents like total protein, free amino acids, trehalose, glycerol and glycogen were estimated in fourth instar larvae of Daba trivoltine ecorace of tropical tasar silkworm so as to differentiate between non-diapause destined (NDD- the first and second crops) and diapause destined (DD- third crop) generations and also to relate them as preparatory for undergoing diapause. There was significant difference in the presence of haemolymph glycogen in female larvae (1.9361±0.9605mg/ml) than male larvae (1.0859±0.5393) in TV third crop. No significant different was observed in remaining constituents. The concentration of trehalose was significantly higher in female larvae (0.9501±0.3784 mg/ml) than male larvae (0.3811±0.2420) in TV second crop. A comparison made between the female and male larvae of second crop shows the higher level presence of amino acids and proteins in male larvae. Rest of the constituents was higher in female larvae than male in second crop. During third crop, except for total free amino acids all other biochemical constituents were higher in male larvae and the difference was observed to be significant in the concentration of glycerol and amino acids A comparison between the non-diapause destined (2^nd crop) and diapause destined (3^rd crop) generations indicated that the diapause destined larvae has significantly higher level of amino acids trehalose (6.5873±3.2437 mg/ml in male, 8.1217±3.0710 mg/ml in female) and glycerol (in female). However, a comparison between NDD first crop and third crop indicated that all the haemolymph constituents were significantly higher in diapause destined fourth instar larvae, like amino acids protein (11.3999 ± 2.5290mg/ml in male, 11.3264 ± 2.5672mg/ml in female), trehalose glycogen and glycerol. The findings indicate that fourth instar larvae of Daba trivoltine of tasar silkworm accumulate energy reserves to skip forthcoming unfavorable conditions in pupal stage. SDS PAGE studies did not indicate any major difference in protein profile but a sharp increase in band intensity of 85kDa, probably a major storage protein and a 43kDa diapause specific band in DD larvae.