This document provides information about sericulture (silk farming). It begins with definitions of sericulture and discusses the history and discovery of silk. It then describes the major types of silkworms and their host plants. The document outlines the three divisions of sericulture production - cultivation of host plants, rearing of silkworms, and reeling of cocoons. Details are provided on the life cycle and rearing of the mulberry silkworm. The document concludes with statistics on global silk production and the role of India's silk industry.

1. SERICULTURE
NEHA AGARWAL
B.Sc HONS.

2. SERICULTURE: MEANING
 Sericulture is the silk producing agro-industry
 India is the second largest silk producing country in
the world after china.
 Sericulture or silk farming is the rearing of silkworm
for the production of silk
 Silk is known as queen of textile and biosteel
because of its strength

3. SERICULTURE: HISTORICAL PERSPECTIVE
A Chinese tale of the discovery of the silkworm’s silk was by an ancient
empress Lei Zu , the wife of the emperor.
She was drinking tea under tree, when a silk cocoon fell into her tea cup and
the hot tea loosened the long strand of silk
As she it out, and started to wrap the silk thread around her flinger, she felt
the warm sensation
When silk ran out, an larva appeared. She realized that it was this larva that
produces the silk
Soon, she taught this to people and it became wide spread

4. TYPES OF SILK
SILK TYPE SILKWORM HOST PLANT DISTRIBUTION
Mulberry silk Bombyx mori Morus alba
M. Indica
M. Serrata
M. Lattifolia
Europe
China
USA
Tropical tasar silk Antheraea mylitta Terminalia tomentosa
(asan or yen)
T. Arjuna (arjun)
Shorea robusta (sal)
Tropical forest zone
ranging from Bihar
Jharkhand to
Karnataka
Temperate tasar silk A, proylei
A. roylei
Quercus serrata(oak) Sub Himalayan region
and n-eastern India
Muga silk A. Assama Machilus bombycina
(som)
Litsaea polyantha (
soalu)
Brahmaputra valley
Eri or errandi silk Philosamia ricini Castor,
Ricinus communis
(kesseru)
Assam and eastern
parts of India

5. Mulberry silk moth Tasar silk moth
Muga silk moth Eri silk moth
Order: Lepidoptera

6. SERICULTURE : STAGES OF PRODUCTION
Sericulture can be divided into 3 divisions as follows:
1. Cultivation of mulberry: Agricultural Division
2. Rearing of cocoon : Entomological Division
3. Reeling of cocoons: Technical Divisions

7. AGRICULTURAL DIVISION
 This includes the cultivation of host plants
 Larval stage of silk moth feed on these plants
 Different plants required different conditions for their
growth. Thus this division is actually the crucial step
 This is the beginning step for the sericulture

8. CULTIVATION OF MULBERRY
(MORICULTURE)
 Mulberry silkworm feeds on mulberry plants of
genus Morus
 M. alba , M. indica , M. serrata , M. latifolia
 Alternate plants: sage, orange, lettuce, peepal
 Climatic conditions: temperate to tropical regions,
15-37°C, rainfall range 600-2500mm, altitude 300-
900m above sea level
 Regions: Karnataka, Andhra Pradesh, Tamil nadu
 Mulberry is deep rooted perennial, grows well in
loamy soil or red sandy loamy (murram)
 Seasons: plantation during early spring and late
autumn with stem cuttings and root grafting.

9.  Plantations can be done by 2 types:
Pit system Row system
o.45-0.9cm
o.75-0.9 cm
Helps in leaf production
0.30-0.60m
0.10-0.25m
In irrigated systems

10. DISEASES OF MULBERRY PLANTS
 Powdery mildew: due to fungus,
Phyllactinia corylea causing yellow brown
patches on the lower surface of leaves.
 Leaf spots: due to fungus, Cercospora
moricola causing circular brownish black
spots on leaves.
 The plants are also attacked by some insect
pests like leaf eating caterpillar (Diarcrisia
oblique), jassid (Empoasca flavescens) ,
mealy bug (Maconellicoccus hirsutus), scale
insects, thrips, stem girdler beetle ( Sthenias
grisator) , powder pest beetle (Sinaxylon
pubens)

11. ENTOMOLOGICAL DIVISION
 This includes the rearing of silk moth.
 This is the most typical and time consuming
process
 This required the complete knowledge of the life
cycle of the interested silk moth, along with its
morphology and anatomy.

12. LIFE CYCLE OF THE SILKWORM

13. Stage Period
(days)
Characters
Egg 9-12 Yellowish-white, semi round, 1mg wt
Larvae
I Instar
II Instar
III Instar
IV instar
V Instar
25-30
3-4
2-3
3-4
5-6
7-8
Last instar larva is greenish, cylindrical
caterpillar, 3-3.5 inches long,bears 3 pairs
of thoracic legs, 5 pairs of prolegs, last pair
modified to claspers, spiracles- 1 thoracic
and 8 abdominal. Each larva feeds on
90gm of leaves during its larval period
(voracious feeders)
Prepupa
Pupa
4-7
10-12
Non feeding stage, cocoon spinning within
2-4 days
Adult
2-3 Robust creamy white moth, bipectinate
antenna, non feeder, poor flier. Each
female lays 400-600 eggs, secretes
alkaline solution to dissolves the
cocoon(fibers)
LIFE CYCLE OF THE MULBERRY SILKWORM

14. Bombyx mori ( Family-Bombicidae, Order-
Lepidoptera)
4 stages: egg, larva, pupa , adult
 Eggs are of 2 types:
The diapause (or
hibernating) type of
eggs :laid by the silk
moth inhabiting in
temperate regions
The non-diapause (or
non-hibernating) eggs
:silk moths inhabitating in
sub-tropical regions like
India

15.  Fifth Larva makes quick round movements of its head
at the rate of 65 movements per minute while spinning its
cocoon.
 Larval stage consist of pair of silk glands, which are
greatly developed, about 4 times the body length and
folded enormously in hind gut
 Silk glands=labial glands
 Silk glands=homologous to salivary glands
 Anteriorly, each gland opens into salivary duct. Both ducts
unite and open at the apex of spinneret

16.  Silk gland composed of single layer
of secretory cells bearing branched
nuclei, internally lined by cuticle and
externally by peritoneal membrane
 Silk gland has 3 parts: anterior silk
gland (250 cells), middle silk gland (
300 secretory cells) and posterior
silk gland (500 cells)
 Anterior part- no secretory function
 Middle part- secrete sericin
 Posterior part- secrete fibroin and
p25

17. 60-70% fibroin
•tough, elastic and insoluble
•Make the core of the
filaments in the form of brins
20-25% sericin
•gelatinous (gummy), hot
water soluble protein
•Holds the brins together
•The weight in gm of 900 m long silk filament is called a “Denier”.
•The size of a normal cocoon is 1.8 to 3 deniers.
•A single cocoon weight is 1.8 to 2 gm and its shell (without enclosed
pupa) is only 0.45 gm.
•About 2500 cocoons yield 0.45 kg of silk.
Silk secretion

18. REARING OF SILK WORMS
Selection Of Silkworm Race: multivoltine race which
complete 5-6 life cycles per year, non-hibernating eggs;
univoltine and bivoltine race also reared in India.
Silkworm Seed Production: hybrids of multivoltine and
bivoltine reared commercially for its superior quality and
huge quantity of eggs (silkworm seed)
Grainages : These are the places where seeds are
produced at large scales; healthy, disease free cocoons of
pure race are selected; preserved at 23-25°C in wooden
trays at 70-80%RH; after emergence, females transferred
to plastic trays allowed to copulate with males of desired
race under black cloth for 3 hrs; within 12 hrs, female lays
400-600 eggs

19. DISEASES OF SILKWORM
4 major diseases:
 Pebrine: protozoan (Nocema bombycis) produce
pepper like spots on body, and larvae become
wrinkled skinned and sluggish
 Flacherie: bacterium(Bacillus thuringensis sotto)
causes putrification of body and body becomes
black-green
 Muscardine: fungus ( Beauveria bassiana) cause
white muscardine in humid condition, while
Spicaria parssina cause green muscardine. Iscaria
farinose cause yellow muscardine. Hyphae come
out from intersegmental membrane all over the
body of the larva
 Glasserie: Borrelina virus cause swelling of
segment and skin rupture

20. PESTS OF SILKWORM
Following parasites and predators cause destruction
of silkworms
 Uzi flies: Tricholyga bombycis (diptera) ; young
maggots bore into the body of silkworms and live in
and eat fatbody for about a week , causing the
death
 Dermestid beetles: Dermestes cadeverinus larvae
and adults feed on cocoons
 Other predators include ant, lizards, rats, squirrels,
birds etc.

21. TECHNICAL DIVISION
 This involves the extraction and purification of silk
fibers from cocoon
 This is the last step for sericulture
 This is the energy consuming and time consuming
step.
 In this, only 30-40% cocoon (pupae) of the rearing
tray are allowed to complete their life-cycle, while
rest are used for obtaining silk fibers
 This is the post-cocoon process
 1kg of silk = 5500-6000 cocoons

22. REELING OF SILK
Harvesting: it is removing and selecting operation of
cocoons from mountages and sell them to market
or to transport to reeling industry
Reeling: removal of silk thread; about 58% of the silk
in each cocoon is relable, remainder is used as silk
waste and formed into spun silk. Raw silk is boiled,
scoured, steamed and purified as follows:
 Cocoon drying: steam stifling (process of killing) of
cocoons is done to kill pupae so that intact cocoon can
be used for reeling. Hot air stifling and sun drying is also
very common
 Cocoon boiling: it is a common practice for swelling,
softening and to some extent dissolution and removal of
sericin and gum. Its is purified by acid and fermentation.

23.  Brushing: by brushing the outer surface of cocoons manually or
mechanically, the free end of silk filament(brins) is recognized. It is
the essential operation for reeling the entire intact thread.
 Reeling methods: unwinding of silk thread from cocoon is done by
country charkha.
The free ends of silk filament of 5-10 cocoons are picked together,
fixed on reeling appliance and twisted into a single thick thread.
The silk obtained is called spun silk

26. PRODUCTION
S.No. Country Silk export
(1000 kg)
Earning
( Int $1000)
1. China 290,003 978,013
2. India 77000 259679
3. Uzbekistan 17000 57332
4 Brazil 11000 37097
5. Iran 6000 20235
Annual export of mulberry silk in world
Over 30 countries, China contributes 54% and India (14%) to the
world production of mulberry silk

27. WORLD RAW SILK PRODUCTION STATISTICS
(In metric tonnes)

29. SERICULTURE : OPPORTUNITIES

30. DISTRIBUTION OF SILK INDUSTRY IN INDIA
 About 80% of the silk produced in the country is
of mulberry silk, majority of which is produced in the three
southern States of Karnataka, Andhra Pradesh and Tamil
Nadu followed by West Bengal and Jammu & Kashmir.
Mulberry sericulture is practised since time immemorial in
the North Eastern Region (NER).
 The tropical Tasar silk is produced largely in the central
India covering the tribal areas of Jharkhand , Chhattisgarh,
Bihar, Madhya Pradesh, Maharashtra, Uttar Pradesh,
Andhra Pradesh, Orissa, etc. Oak Tasar is produced in
Manipur, Mizoram, Nagaland, Uttarakhand, Jammu &
Kashmir, etc.
 Eri is grown in Assam and the adjacent north-eastern
states, Bihar, West Bengal and Odisha.

31. CENTRAL SILK BOARD (CSB)
 Central Silk Board, Government of India in the year
1958
 Ministry of Textiles, Govt. of India

32. CENTRAL RESEARCH INSTITUTE OF INDIA
1. Central Sericulture Research and Training
Institute, Mysore (Karnataka).
2. Central Sericulture Research and Training
Institute, West Bengal
3. Central Tasar Research and Training Institute,
Ranchi (Jharkhand).
4. Central Silk Technological Research Institute
(CSTRI), Bangalore (Karnataka).