Biochemical aspects of diapause preparation in penultimate instar of tropical tasar silkworm Antheraea mylitta Drury

P.K. Mishra*, D. Kumar, L. Jaiswal, Ashutosh Kumar, B.M.K. Singh, S.K. Sharan,
J.P. PANDEY
and B.C. Prasad

Silkworm Physiology Laboratory, Central Tasar Research and Training Institute, P.O. Piska-Nagri, Ranchi, India

ABSTRACT

The haemolymph biochemical constituents (total protein, free amino acids, trehalose, glycerol and glycogen) were estimated in penultimate instar larvae of Daba bivoltine ecorace of tropical tasar silkworm Antheraea mylitta Drury in non-diapause destined (NDD) and diapause destined (DD) generations. In the phago-period of penultimate instar male and female larvae of the same generation there was no significant difference in haemolymph biochemical constituents although protein level was higher in female (7.9562.821mg/ml in NDD and 5.1442.268 mg/ml in DD) than male larvae (6.0862.467mg/ml in NDD and 4.8502.202 mg/ml in DD). Trehalose was also higher in female larvae than male. In DD generation, glycogen content was higher in male than female larvae. Amino acids, trehalose, glycogen and glycerol were higher in DD male and female larvae than their NDD counterparts. However, protein was higher in male and female larvae of NDD generation. At the beginning of instar period, protein was lower but it increased at the end of the period. Amino acids were higher in the beginning of an instar period except in females of DD but gradually decreased at the end of the period. Trehalose was always high two days prior to the end of the instar period in both the generations. Glycerol was low in the mid instar period but increased slightly at the fag end of instar period except in male larvae of DD where there was a peak on day 2. Glycogen was higher during mid instar period. The lower level of glycogen coincided with the higher level of trehalose in the haemolymph.

Key words: Haemolymph, Amino acids, Protein, Glycogen, Glycerol, Trehalose, Antheraea mylitta, NDD, DD