Sericulture

Sericulture, or silk farming, is the rearing of

silkworms for the production of silk.

Sericulture is both an art and science of

raising silkworms for silk production.

Silk is a natural protein fiber, some forms of

which can be woven into textiles. The
protein fiber of silk is composed mainly of
fibroin and produced by certain insect
larvae to form cocoons.
 HISTORY OF SERICULTURE
• Silk was discovered in China and industry spread from there to other parts
of the world.
• Chinese Empress Shiling Ti discovered it in her tea cup during 2640 BC.
Suddenly, a silkworm cocoon fell in her tea cup. Empress took the cocoon
out from her bowl and found that it started to unwind and the thread was
endless, unbreakable, seductive and lustrous.
• The thread could be used to make a wonderful yarn. Since then the empress
has been called “the Silk Goddess”.
 TYPES OF SILK IN INDIA
 There are five major types of silk of commercial importance, obtained
from different species of silkworms which in turn feed on a number of
food plants.

 Except mulberry, other varieties of silk are generally termed as non-

mulberry silks. India has the unique distinction of producing all these
commercial varieties of silk:

1. Mulberry Silk
2. Tasar Silk
3. Oak tasar Silk
4. Eri Silk
5. Muga Silk
 Mulberry Silk

• The bulk of the commercial silk produced

in the world comes from this variety.
• Mulberry silk comes from the silkworm,
Bombyx mori which solely feeds on the
leaves of mulberry plant (Morus alba, M.
indica).
• In India, the major mulberry silk producing
states are Karnataka, Andhra Pradesh,
West Bengal, Tamil Nadu and Jammu &
Kashmir which together accounts for 92
% of country's total mulberry raw silk
production
 Tasar silk

• Tasar (Tussah) is copperish colour, coarse silk mainly used for

furnishings and interiors.
• Tasar silk is produced by the silkworm, Antheraea mylitta,
which mainly thrive on the food plants Asan and Arjun (
Terminalia tomentosa, T. arjuna)
• In India, tasar silk is mainly produced in the states of
Jharkhand, Chattisgarh and Orissa, besides Maharashtra,
West Bengal and Andhra Pradesh.
 Oak Tasar

• It is a finer variety of tasar produced by the silkworm, Antheraea

proyeli in India, which feeds on plants of oak, (Quercus serrata,
Q. incana) found in abundance in the sub-Himalayan belt of India
covering the states of Manipur, Himachal Pradesh, Uttar
Pradesh, Assam, Meghalaya and Jammu & Kashmir
• China is the major producer of oak tasar in the world and this
comes from another silkworm which is known as Antheraea
pernyi
 Eri Silk

• Also known as Endi or Errandi, Eri is a multivoltine silk,

spun from open-ended cocoons, unlike other varieties of silk
• Eri silk is the product of the domesticated silkworm,
Philosamia ricini , Attacus ricini that feeds mainly on castor
leaves ( Ricinus communis)
• The silk is used indigenously for preparation of chaddars
(wraps) for own use by tribals. In India, this culture is
practiced mainly in the north-eastern states and Assam. It is
also found in Bihar, West Bengal and Orissa
 Muga Silk

• This golden yellow colour silk is prerogative of India and the pride of
Assam state. It is obtained from semi-domesticated multivoltine
silkworm, Antheraea assamensis
• These silkworms feed on the aromatic leaves of Som ( Machilus sp.)
and Soalu ( Litsea sp.) plants
• Muga culture is specific to the state of Assam and an integral part of
the tradition and culture of the state. The muga silk, a high value
product, is used in manufacturing of sarees, mekhalas, chaddars, etc
 Mulberry Silk

Insect: Bombyx mori

Food: Mulberry leaves
Life Cycle Of Bombyx mori
 1. Egg:
• A female moth lays about 400 eggs in
a single laying.
• Egg is round and white.
• The weight of newly laid 2,000 eggs
is about 1.0 g.
• Measurement: 1-1.3 mm in length
and 0.9-1.2 mm in width. With time,
eggs become darker and darker.
• The duration of life cycle spent in the
egg stage varies depending upon
whether it is a hibernating or a non-
hibernating egg.
• Hibernating eggs under natural
conditions remain dormant for
months till the spring season in the
next year. Diapause (period of
quiescence/dormancy) can be broken
artificially by acid treatment.
• Non-hibernating eggs normally
complete their embryonic
development in 9-15 days, and hatch
out into larvae.
 2. Larva
• After 10 days of incubation, the eggs
hatch into larva called caterpillar.
• About 0.3 cm in length and pale
yellowish white, densely covered with
bristles.
• The larval body is composed of head,
thorax and abdomen.
• The head consist of six fused segments. It
carries the appendages: antennae,
mandibles, maxillae and labium.
• Six pairs of larval eyes or ocelli are
located a little above the base of antennae.
• The thorax has three segments: prothorax,
mesothorax and metathroax.
• Each of the thoracic segments
carries ventrally one pair of
true legs, which are conical in
shape and carry sharp distal claws.
• The final larval instar after
full growth empties its gut,
stops feeding, and spins the
cocoon of silk around it.
• The last instar larva is 10
cm long

S.N. LARVAL TEMPERATURE HUMIDITY

STAGES
1. I Instar 26-28 85%

2. II Instar 26-28 85%

3. III Instar 24-26 80%

4. IV Instar 24-25 75%

5. V Instar 23-24 70%

 3. Pupa
• Pupa is the inactive resting
stage of silkworm.
• The pupal moult occurs
within the cocoon spun by
the final instar larva.
• Pupae can be seen only by
cutting open the cocoon.
• Pupae are soft and white
soon after the moult but
become hard and brown,
with the tanning of the pupal
cuticle.
• The pupa is a non-motile and
non-feeding stage. The larval
organs are degenerated and
adult organs are
differentiated during this
stage.
 4. Adult
• The adult of Bombyx mori is about
2.5 cm in length and pale creamy
white.
• It does not feed during its short
adult life.
• The antennae are conspicuous,
large and bipectinate.
• The meso- and meta-thorax bear a
pair of wings.
• The moth is unisexual and shows
sexual dimorphism.
• In male eight abdominal segments
are visible; while in female, seven.
• The female has smaller antennae,
body and the abdomen are stouter
and larger, and it is generally less
active than male.
• Just after emergence,
male moths mate with
female for about 2-3
hours, and die after that.
• The female starts laying
eggs just after mating,
which is completed
within 24 hours.
• A female lays 400-500
eggs.
• The eggs are laid in
clusters and are covered
with gelatinous secretion
of the female moth.
Duration of different stages of life cycle of mulberry
silk worm

S.N. Particulars Uni/ bivoltine Multivoltine

1. Egg 11-14 days 9-12 days

(after break of
diapause)
2. Larva 24-26 days 20-24 days

3. Pupa 12-15 days 10-12 days

4. Adult life span 6-10 days 3-4 days

 Sericulture Industry in India
• India is the second largest producer of raw silk after China and the
biggest consumer of raw silk and silk fabrics.
• India has a distinct advantage of practicing sericulture all through
the year, yielding a stream of about 4 – 6 crops as a result of its
tropical climate.
• In India, sericulture is not only a tradition but also a living culture.
• It provides income and employment to the rural-based farmers.
• Several socio-economic studies have affirmed that the benefit-cost
ratio in sericulture is highest among comparable agricultural crops .
• Central Silk Board (CSB), Bangalore under the Ministry of
Textiles, Govt. of India is the apex body for overall development of
sericulture and silk industry in India.
• The functions assigned to the Board are to promote development of the silk industry
by all appropriate measures like undertaking, assisting and encouraging scientific,
technological and economic research, improvement of mulberry cultivation,
production and distribution of healthy silkworm seed, production of quality raw silk
and promotion of silk market etc.

Fig 1: Variety-wise raw silk production in India

Source: Indian Silk 47(5),

Global Silk Production (in Metric Tonnes)
 SERICULTURE INDUSTRY
• The production of silk from silk worm by following scientific rearing
methods is called sericulture. It is an agro-based industry with small scale as
well as commercial potential.
• The phases involved in the process include
1. Selection of races of B. mori
2. Plantation of mulberry
3. Rearing of silk worm
• Emergence of moth and fertilization
• Egg laying
• Hatching
4. Supply of seed
5. Spinning of cocoon
6. Marketing of cocoon
• Post cocoon processing:
1. Stifling
2. Reeling and Spinning
 Selection of races of B. mori
• Worms are introduced through DFLs
(Disease Free Layings, i.e. eggs)
procured from a quality centre (called
grainage).

 Plantation of mulberry
• Rearing of silkworms involves
cultivation of mulberry trees, which
provide a regular supply of leaves
• Generally, the mulberry plants are raised
from semi-hardwood cuttings.
• Cuttings are selected from well
established garden of 8-12 months old.
• Only full grown thick main stems, free
from insect and disease having a
diameter of 10-12mm are chosen for
preparation of cuttings.
 Rearing of silkworm
• The silkworms are actually larvae of
the silk moth. They are reared in
specially made trays in rooms with
controlled temperature and humidity
and regularly fed mulberry leaves.

 Spinning of cocoon
• The larva before transferring into
pupa, stops feeding at the end of 5th
stage and starts spinning cocoon.
When larva grows fully stop feeding
and passes out the stomach content
and the mature larva becomes
translucent and yellowish in
appearance.
• It is a symbol of ripening and at this
stage larva should be picked up and
mounted on mountages or cocooning
frames where they spin cocoon.
 STIFLING
• The process of killing the cocoon
is termed as stifling and is done
by dropping in hot water or
subjecting to steam or dry heat or
sun exposure or fumigation.

 REELING
• The process of removing threads
from the killed cocoon is called
as reeling. The silk is unbound
from the cocoon by softening the
sericin and then delicately and
carefully unwinding, or 'reeling'
the filaments.
Usually 8-10 cocoons are reeled together. There are
three methods for reeling: the charkha, the slightly
more advanced cottage basin and the costly
automatic machines.

The threads of the cocoons are passed through

eyelets and guides to twist into one thread which is
wound round a large wheel and then to spool.

This is called RAW SILK or REELED SILK. Raw

silk is further processed to bring out the final silk
thread.
 References

• http://csb.gov.in/silk-sericulture/sericulture/
• http://agritech.tnau.ac.in/sericulture/seri_silkworm%20types.html
• https://inserco.org/en/evolution_of_silk
• https://www.advantour.com/silkroad/history-of-sericulture-in-
china.htm
• Dr. M. N. Narasimhanna (1988), Manual on silkworm egg
production.
• S. P. Nandy, Sericulture Manual
• D. Gangopadhyav, Sericulture Industry in India
• Silkworm Rearing (Mulberry) Booklet No. 448,Sericulture: SERS - 2
 MERITS OF SILK INDUSTRY
 The industry activities align with the 4 major Millennium Development
Goals set by UN like; eradicate extreme poverty and hunger, promote gender
equality and empower women, ensuring environmental sustainability, and
develop a global partnership for development.
 High Labour Force Participation Rate (LFPR) in comparison to any other
rural avocation due to which silk industry has emerged as the ideal tool for
employment generation and rural development.
 Major participation (80%) by the tribal and downtrodden people, due to
which significantly contribute to the poverty alleviation programmes of the
Government.
 Participation of women (60%) and family members leads to higher income
flow to the family.
 60% of the income from the sericulture industry is flowing to the
primary producers; i.e. farmers.
 Enable flow of equity from rich (the higher level consumers) to poor ( the
farmers, reelers, weavers etc.)
 Prevents urban migration and contribute to preserve the bio-diversity of rural
areas and natural vanya food plant forest areas.
 Low investment and higher return, short gestation period, and
steady income throughout the year.
 The activities are simple and can be taken by women and other family
members along with their regular house hold work.
 Eco friendly production process, increases green cover, helps soil
conservation and prevents soil erosion.
 Carbon emitting is minimal as the industry is agro-based and labour
intensive.
 Land unsuitable for food crop cultivation could be used for
sericulture.
 The waste generated from the industry could be utilized various useful
purposes.
 A strong and assured domestic demand for silk and silk products
which is consistently in the upward trajectory for the last 5 decades.
 Increasing consumption of silk products witnessed in most of the
developed countries leads to high demand in global market also.
 Foreign exchange earning opportunity for the developing countries.