EVALUATION OF PHYSICO-CHEMICAL CHARACTERISTICS OF SILK FIBERS ANTHERAEA-ASSAMA REARED ON DIFFERENT HOST PLANTS

The golden-yellow silk fibres obtained from Antheraea assama Westwood (Lepidoptera: Saturniidae) reared on leaves of three different host pl ants belonging to the family Lauraceae, were studied to evaluate their characteristic physico-chemical properties. The host plants, Machilus bombycina king, Litsaea polyantha A. Juss and Litsaea citrata Roxby, significantly influenced silk length width, sericin and amino-acid con tents of the fibres. The contents of the predominant amino-acids; glyc ine (10.55 mu g), aspartic (5.43 mu g) and serine (7.15 mu g), were hi gher in fibres obtained from cocoons of A. assama fed on M. bombycina, while alanine (9.46 mu g) was higher in the fibres of cocoons obtaine d from the other two host plants. The breaking load (17.791 g) and ten acity (3.562 g/d) were higher in cocoons from the host plant M. bombyc ina The X-ray diffraction patterns showed the amorphous nature of the fibres obtained from the cocoons of A. assama fed on L. polyantha and L. citrata, while fibres obtained from cocoons from M. bombycina showe d amorphous bands with little tendency to two dimensional order Above all, the natural golden yellow hue of the fibre, which is one of the m ost important and commercially? valuable added properties of this part icular silk variety, was better retained in the fibres extracted from cocoons of A. assama larvae reared on M. bombycina. (C) 1998 Elsevier Science Ltd. All rights reserved.