~ 2198 ~ Journal of Entomology and Zoology Studies 2021; 9(1): 2198-2203 E-ISSN: 2320-7078 P-ISSN: 2349-6800 www.entomoljournal.com JEZS 2021; 9(1): 2198-2203 © 2021 JEZS Received: 24-10-2020 Accepted: 22-12-2020 KA Murugesh Department of Sericulture, Forest College & Research Institute, Tamil Nadu Agricultural University, Mettupalayam, Tamil Nadu, India K Chozhan Department of Sericulture, Forest College & Research Institute, Tamil Nadu Agricultural University, Mettupalayam, Tamil Nadu, India R Aruna Department of Sericulture, Forest College & Research Institute, Tamil Nadu Agricultural University, Mettupalayam, Tamil Nadu, India Corresponding Author: KA Murugesh Department of Sericulture, Forest College & Research Institute, Tamil Nadu Agricultural University, Mettupalayam, Tamil Nadu, India Enhancement of larval and cocoon traits of silkworm, Bombyx mori L. through the application of amino acids KA Murugesh, K Chozhan and R Aruna Abstract Experiments were conducted by administering different amino acids viz., Glycine, Alanine and Serine with mulberry leaves to enhance the larval and cocoon traits of Bombyx mori L. Supplementation of amino acids to silkworm larvae once daily in the morning from the first day of the fifth instar to spinning significantly enhanced the larval, protein, cocoon and silk reeling traits. Among the different amino acid combinations tested, it was found that the treatment with Glycine @ 10 ppm + Alanine @ 100 ppm + Serine @ 100 ppm registered significantly highest fifth instar larval weight (4.48 g), ERR (96.50%), silk productivity (6.38 cg/day), silk gland weight (1.12 g) and silk gland length (31.05 m), cocoon weight (2.63 g), shell weight (0.60 g), pupal weight (2.03 g), shell ratio (22..81%), filament length (1220 m) and filament weight (0.440 g). The proteins in the silk gland (64.70 mg/g) and haemolymph (48.50 mg/ml) were also found to be the highest in the above treatment apart from fibroin (420 mg/shell) and sericin (107.05 mg/shell) contents in cocoons. It is concluded that feeding the silkworm by amino acids viz., glycine, alanine and serine fortified mulberry leaves during the fifth instar significantly improves the larval, cocoon and silk reeling traits. Keywords: amino acids, glycine, alanine, serine, silkworm Introduction The silkworm, B. mori. secretes the lustrous raw material for the production of the queen of the textiles which could not be substantiated even by the advanced scientific innovations. "As it spins it protects the millions" says a popular Chinese adage. True to this proverb, sericulture provides gainful employment for more than nine million people in India. Silkworm nutrition plays an important role in improving the growth and development of B. mori. The silkworm is a monophagous insect derives its entire nutritional requirement from mulberry leaves. Silk fibroin is derived mainly from four amino acids viz., alanine, serine, glycine and tyrosine which come from their dietary source of protein and amino acids [1] . The silkworm obtains 72-86 per cent of their amino acids from mulberry leaves and more than 60 per cent of the absorbed amino acids are used for silk production [2] . It is well proved that amino acids play an important role in glucose, tryptophan and organic acid metabolism. The nutritive value of mulberry leaves plays a crucial role in producing good quality cocoons and raw silk. The better growth and development of silkworm larvae and economic traits of cocoons were observed when the larvae were fed with good quality leaves [3] . Though the nutrients are balanced in mulberry leaves, the quantity available is not sufficient for vigorous and healthy growth and development of silkworm larvae [4] . The nutritional status of mulberry leaves is altered by supplementing them with different ingredients and food additives. Among various supplementation experiments with amino acids, vitamins, antibiotics, minerals, etc., the fortification of mulberry leaves with amino acids seems to be much promising since it improved the quality of leaf and silk yield by 40-60 per cent [5] . Various studies conducted by different workers on amino acid supplementation revealed considerable improvement in silk production. The supplementation of various amino acids viz., phenylalanine [6] , glycine, alanine and serine [7] , tyrosine, phenylalanine and alanine [8] , glycine [9] , glycine, phenylalanine, serine and aspartic acid [10] , asparginine [11] and arginine and histidine [12] have improved the larval traits, cocoon traits and silk productivity. But, the studies on the effects of the amino acid combination on silkworm are very limited. By keeping this in mind, the experiments were carried out to assess the influence of amino acid combinations on the growth & development of silkworm and their impact on cocoon and silk reeling related traits.