Lecture 8 Types of silk worm.pptx

Silkworm

1. Lecture 8 Types of silkworm - Mulberry silkworm – origin – classification based on voltinism , moultinism , geographical distribution & genetic nature – Characters of multivoltine races, bivoltine races, cross breeds and bivoltine hybrids – double hybrids– suitability for rearing in different seasons

2. History of silk worm Silkworm industry originated in China about 3000 B.C. Chinese Princess Hsi -ling-chi – serendipity Silk = most elegant textile in world natural sheen, easily mix with dyes, high absorbance, light weight, soft touch and high durability “Queen of Textiles”. India - 5 types of commercial silks viz., mulberry, tropical tasar , oak tasar , eri and muga .

3. Systematic position Mulberry silkworm Scientific name : Bombyx mori Family : Bombycidae Super family : Bombycoidea Order : Lepidoptera

4. Types of Silk Type of silk Distribution Type of Silk insects Mulberry Karnataka, Andhra Pradesh, Tamil Nadu, Kerala, Maharashtra,West Bengal and J&K Bombyx mori ( Bombycidae ) Tasar (Undergoes pupal diapause ) Jharkhand, Bihar, Chhattisgarh, Madhya Pradesh, Orissa and West Bengal & Andhra Pradesh Tropical tassar (India) Antheraea mylitta ( Saturniidae ) Temperate Tassar Antheraea proylei (India) Antheraea yamamai (Japan) Antheraea pernyi (China & USSR) Eri Assam, Bihar, Manipur, Meghalaya, Nagaland & West Bengal Attacus (= Philosamia ) ricini ( Saturniidae ) Muga (only in India) only in Assam (pride of Assam), parts of Tripura Antheraea assamensis ( Saturniidae )

5. Types of silk worm (larva) Mulberry silk worm Tassar silk worm Eri silk worm Muga silk worm

6. Types of Silk, food plants & color of silk Type of silk Food plants Colour of silk produced Mulberry Morus alba (Mulberry) Creamy white Tasar (Undergoes pupal diapause) Terminalia arjuna ( Arjun ), Terminalia tomentosa ( Asan ), Zizyphus jujuba (Plum), Shorea robusta (Sal), Oak coppery colour – non-reelable only spun. Furnishings & interiors Eri Ricinus communis (castor) Brick-red silk Muga (only in India) Tetranthera monopetala ( Som ), Michalia oblonga ( champa ), Litsaea polyantha ( Moyankuri ) Golden colour , costly

7. Morus alba Ricinus communis Zizyphus jujuba Tetranthera monopetala

8. Silk worm life cycle 4 stages Eggs  baby worms = Black worm/ ant/ kego I & II instar  feed - fresh succulent mulberry leaves until they reach III instar . III instar  whole branch of mulberry leaves fed to worms Silkworms feed until they enter cocoon ( Pupal ) stage While spinning cocoons, worms produce jelly-like substance in their silk glands, which hardens upon contact with air and spin cocoons around them After 4-5 days in a warm, dry place, cocoons are ready to be unwound. Total life cycle = 25 to 35 days (depending upon race and climatic condition)

9. CLASSIFICATION OF MULBERRY SILKWORM Based on voltinism Univoltines , bivoltines and multivoltines Based on moultinism tri moulters, tetra moulters and penta moulters. Based on geographical distribution Chinese, Japanese, European and Indian races Based on genetic nature pure races and hybrids

10. Differences between Uni - Bi- & Multivoltine races Races Univoltine Bivoltine Multivoltine Generation/ year One Two > 2 Larval duration relatively longer longer Short larval weight higher Highest lower Cocoon weight heavy Heavier Less heavy Denier > 2.3 Tolerance Not tolerant to Higher temperatures tolerate environmental fluctuations Well adapted to tropical conditions Races European races Japanese and Chinese races Indian races Diapause lay only diapausing eggs Lay diapausing eggs & non diapausing eggs Lay non- diapausing eggs Commercial value commercially superior commercially superior Poor quality

11. Multivoltine X Bivoltine (cross breeds) P a r a m e t e r N a t i v e pu r e li n e s C r o s s b r e e d P M x N B 4 D2 B i v o l t ine h y brid C S R 2 x C S R 4 C o c o o n w e i g h t ( g ) 1 1 .7 1 .9 S h e ll w e i gh t ( g ) 1 1 7 2 4 F i l a m en t l e n g t h ( m ) 3 - 4 73 1 1 5 N e a t n e ss ( p o i n t s ) L e s s 8 2 9 4 R e n d it ta 1 - 1 5 9 5 Renditta number of kilograms of fresh cocoons required to produce one kilogram of raw silk

12. Silk worm larva

13. Silk worm pupa

14. Silk worm facts… Female silk worm moth lays - 300 to 500 eggs After 5-6 moults , the silkworm extrudes a silk fibre from its salivary gland (swinging itself from side to side in 8 shape) and forms silken coccon . Silkworm spins ~2 kms of filament in 2/3 days. ~2,500 silkworms = 1 pound (0.45 kg) of raw silk Intact cocoons  boiled to kill the silkworm pupa One cocoon  1,000 yards of silk filament (910 metres ) Silk at this stage = raw silk What is meant by ahimsa silk??