Rearing techniques for successful cocoon crop.pptx

Rearing techniques for
successful cocoon crop
Dr. Kuntamalla Sujatha
Asst Professor of Sericulture
Department of Zoology
Kakatiya University, Warangal
1
Dr. K. Sujatha, Assistant Professor, Kakatiya University

SERICULTURE
 Sericulture is defined as rearing of silkworms by following
package of practices for production of quality silk.
 It involves moriculture i.e. mainly cultivation and
maintenance of garden
 Grainage – Production of quality seeds free from diseases
 Rearing – culturing of silkworms
 Reeling – unwinding of silk from cocoons etc
2

•Sericulture is an eco friendly, agro based labour
intensive and commercially attractive economic
activity
•It is only cash crop that provides attractive returns
in short gestation period
•Globally China occupies the first place with
1,03,620 MT while India is second largest producer
with 19,690 raw silk.
3

IMPORTANCE OF SERICULTURE
 High employment potential
 Benefits the villages
 Low gestation, low investment with high return
 Women friendly
 Upliftment of rural weaker section of societies
 Eco friendly with additional income from by products
 Indigenous technology at low cost
 Stops migration of rural people to urban areas for
employment
4

Historical perspective
 Historical evidence show that China is homeland of silk
 During 2500 BC, when wife of great yellow empire Shi Huaug,Shi ling
shi was sitting under a tree drinking her herbal tea, when a cocoon
fell into it, she tried to remove but a fine lustrous yarn unwinded .
 Empress is credited with silk invention and is worshipped as “Goddess
of silkworm”
 Silk cocoons cut into half are found at the sites of Yangshao culture in
Xia country.
 Silk is described in chapter of the Fanshenqzhi shu (206 BC -9 AD)
ancient silk road
 Silk road was opened by China in the 2nd century AD
 This road of 6400 km length is called as silk road
 Through this route ,silk was exchanged for gold ,wool, horses, glass
etc. 5

History of Indian sericulture
 Silk was mentioned in Rig-veda, Ramayana and
Mahabharata
 Domestication of silkworm Bombyx mori originated in sub
Himalayan regions
 The silk was mentioned “UMS’’ a type of silk
6

3a TYPES OF SILKWORMS
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MULBERRY ERI
MUGA TASAR
TYPES OF SILKWORM COCOONS:-
8

MULBERRY ERI
MUGA TASAR
TYPES OF SILKWORM MOTH:-
9

REARING
 Rearing is following package of practices to get quality
cocoons
 Mulberry silkworms are delicate, cannot tolerate adverse
environmental changes hence reared in special rearing house
10

REARING REQUIREMENTS
 Mulberry growth
 Yield and quality mulberry leaves
 Silkworm race reared
 Availability of labour
 Rearing facilities
 Suitable rearing technology adopted
 Proper hygiene and sanitization conditions
 Optimum environmental conditions
11

TYPES OF REARING HOUSES
 Mud wall & country tile roof
 Mud wall & mangalore tile roof
 Mud wall with thatched roof
 Bamboo mat wall with thatched roof
 Double wall with thatched roof
 Plank wall with thatched roof
 Double wall with mangalore tiles
 RCC roofed houses
12

EQUIPMENTS REQUIRED
 Rearing stands
 Rearing trays
 Ant wells
 Paraffin paper
 Foam rubber strips
 Chop sticks
 Chopping boards, mats, feather, earthern pots,
leaf chamber, cleaning nets, mountages, foot
cleaning trays etc.
13

Disinfection
 Disinfection is foremost operation in rearing
 It forms an integral part which aims us destruction of
diseases causing germs within and outside rearing house
 Cleaning of rearing house and surroundings are to be
done prior to disinfection
a)removal of dust and dirt
b)washing of room and equipments with hot and clean
water
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METHOD OF DISINFECTION
 May be physical or chemical methods
 Most effective & simple method is using chemicals
 Disinfectants should be easy available , simple in
adapting, low cost and without damage to the building or
equipments
15

Physical methods
 Sun drying:-exposing to direct sunlight
 Streaming:-steam is used to disinfection of rearing room & appliances
 Hot air :-hot air is utilised for disinfecting but it not adapted in India
due to high cost factor.
Chemical methods
 Most commonly used disinfectant are formalin, bleaching
powder ,slaked lime, chlorine dioxide etc .
 Rearing equipments such as rearing trays, feeding stands etc.
which are small & handy are either dipped or sprayed with
formalin , bleaching powder or sodium hypochlorite
16

Rearing house
 Rearing house is disinfected uniformly with 2% formalin
solution under ideal room temperature
 Maintenance of hygienic conditions during rearing helps in
prevention, spread and control of diseases
 To get good cocoon crop, proper disinfection and hygienic
conditions in the rearing house and surrounding is a
mandatory
17

Environmental conditions
instar Temperature Humidity
I 27°-28°c 85-90%
II 26°-27°c 85-90%
III 25°-26°c 80-85%
IV 24°-25°c 75-80%
V 23°-24°c 70-75%
• The environmental changes affect the growth,
health of silkworms, ultimately on crop yield and
quality hence regulation of environmental
condition according to season, place and
silkworm races are important.
• Fresh air of 1.0 m/sec and dim light(15 -20 lux)
during day time and darkness at night are
important from the physiological point of
silkworms.
18

Incubation
 Incubation is a process of protecting the
activated silkworm eggs before hatching.
 It is necessary to incubate the eggs properly
1. To get high and uniform hatching
2. Good larval health
3. Quality cocoons
 Optimum conditions in incubation room
Temperature-24°C -25°C
Humidity-80-85%
19

Black boxing of eggs
 When eggs are incubated under suitable conditions
they reach pin head or head pigmentation before 48
hours hatching, this stage is called eyespot stage.
 Next the whole body turns black due to
development of body pigments and this stage is the
blue egg stage.
 In blue egg stage, the eggs are kept in black box/
paper/cloth.
REASONS
1. Prevent early maturing embryos from hatching
2. Give time for late mature worms to catch with early mature worms
3. To favour 90% hatching
20

21

Hatching of eggs
 Hatching is the phase when the newly developed silkworm
come out of egg shells
 The newly hatched larvae are black ,hairy are called ants
or kego
 In the early hours, all the eggs exposed to diffused light
for uniform hatching.
 Hatching starts from 5 a.m. to 6 a.m, uniform hatching is
expected 7:30 to 8:30 a.m.( weather conditions).
22

Brushing
 Brushing is the process of separating the ants from the egg
shells
 Optimum conditions -
Time: 10 a.m. to 11 a.m.
Temperature 26°C to 27°C
Humidity:85 to 90%
Brushing time is 10:00 a.m.
 Tender mulberry leaves chopped to 3-5 mm size are fed to
worms.
 The hatched kegos crawls onto the leaves.
 Brushing is of two types
1. Brushing of loose eggs.
2. Brushing of egg card
23

Brushing of loose Eggs
 The eggs that reach blue stage are spread in a single layer after removal from
black box
 Just before brushing, chopped mulberry leaves are sprinkled on the net or
cloth or paper.
 When maximum worms crawl on to the top, they are separated onto a rearing
tray
Brushing from egg card
 Tapping method
 Feather method
 Brushing with mulberry leaves
 Husk feeding method
24

Selection of mulberry feed
 Leaf selection for feeding has great impact on growth
and health of silkworm.
 Two methods of leaf selection
1. Glossy leaf method
2. Lenticel and bud method
 The leaf quality is influenced by various factors
1. Soil
2. Pruning
3. Balanced Fertilizers
4. Rainfall/ irrigation
5. Seasons
25

Feeding schedule
 Silkworm are fed to satisfy their appetite.
Objective of feeding
 To satisfy the appetite
 To maintain the leaves quality
 To keeping rearing seat clean
 To avoid wastage and labour cost
 To get quality cocoons
 Early chawki worms eat the mulberry leaves from
surface while late age worms from the edges
26

Leaf preparation for feeding
 Leaf quality is influenced by chopping.
 Advantage of chopping is to facilitate even distribution of feed for
the worms
Instar To start Leaf size peak
eating stage
Leaf size during
moulting
I 0.5 2 1
II 2.0 4 1.5
III 4.0 Leaf cut into four
piece
2.0
IV Whole leaf
V Whole leaf
27

Frequency of feeding
 The worms are fed four times in summer while in winter three times daily.
 Timing:-
5 a.m. 11 a.m. 5 p.m. and 9 p.m.
. 4 times/day in summer
9 a.m. 4 p.m. 10:00 p.m.
3 times/day in winter
Preservation of leaves
 It’s important to preserve the nutritive value and succulence of the feed after
harvest till it is consumed by the worms.
Reasons for preservation
 Leaves show high moisture content and protein.
 Help in digestibility of worm.
 To avoid fermentation and release of heat.
 Reduces no of feeds and labour tender
 Tender leaves for chawki worms are preserved in pots covered with wet cloth
28
Dr. K. Sujatha, Assistant Professor, Kakatiya Univers

Bed cleaning
 Silkworms are fed with large quantity of mulberry leaves
than their eating capacity
only 2/5 of leaf is assimilated while 3/5 of is excreted.
 Bed cleaning is a process of removal of old mulberry
leaves, faecal matter of silkworm, dead worms etc
29

Frequency of cleaning
 I instar once
 II instar twice
 III instar thrice
 IV instar daily
. Methods of cleaning
 Cleaning with husk.
 Cleaning with the net.
 Cleaning with the husk and net.
Prior to first feeding, charred husk or paddy husk is sprinkled
over the silkworm seat while worms crawl through the husk
layer to reach the feed .
30

Rearing
 Duration of larval period from hatching to spinning is about 26 days.
 During this period, the larva eats voraciously to grow in size.
 To facilitate silkworm growth, it undergo 4 moults thus can be
differentiated into five instars
 Out of the five instars, the first three instars till third moult is called
chawki worms or young age worms when it consumes 15 to 20% of the
total feed
 While the 4th and 5th instar is called the late age worms when it
consumes 80% of the total feed
31

chawkie rearing
 The success of sericulture depends on chawkie
rearing
 Chawkie worms are resistant to high temperature
and humidity
 During the instars, body weight increases by 400
times, body size by 300 times and silk gland
weight by 500 times
 Methods of chawki rearing
1. Paraffin paper method
2. Rearing in box
3. Co operative rearing 32

Paraffin paper method
 Paraffin paper is laid as bottom and top layers
with foam pads on all four sides of rearing seat.
 While feeding the worms, the top paraffin
sheet is removed 30 minute prior.
Box Rearing
 Box are used for rearing.
 Box may be with lid or without lid
 In this method, the boxes are arranged in
shelves with lids but from the third instar lids is
not used.
33

34

Co-operative rearing
 Silkworm rearing requires technical skills to overcome problems
during rearing . On large scale, co-operative rearing centres are
organised to provide technical assistance upto 3rd moult with good
crops & income to the rearers,
 It’s popular in japan, after rearing till third moult, the silkworms are
distributed to farmers
 Advantages
1. Stable and high cocoon quality
2. It saves labour and the time
3. Reduces expenditure
4. Lower investment
5. Effective disease control
35

Late age rearing
 The fourth and fifth instar silkworms are active
eaters and silk glands develops fully during these
instars.
 Body volume increases by 29 times, body weight
by 25 times and silk gland weight by 200 times
 Methods of rearing
1. Shelf rearing
2. Floor rearing
3. Shoot rearing
36

Shelf rearing
 Rearing trays are arranged in stands.
 In each stand 10 trays are placed.
Merits
 More worms are reared in a limited area.
 Requires more air and light.
Demerits
 Production cost is more
 Labour requirement is more.
37

Floor rearing
 The rearing of silkworms is carried on fixed seats arranged in two or three
tiers
 Rearing seat measures 1-1.5 m (width), length of 5-7m and height of 0.6-
0.8 m between the tiers
 The worms are fed with whole leaves or branches
Merits
 Saves time in feeding and cleaning
 Reduces production cost
 Saves labour cost
 More worms are reared
 incidence of diseases is minimized
38

Shoot rearing
 It’s a economical method
 The rearing tiers are arranged 20 cm above the ground
with a gap of 1 m between the tiers
 shoot feeding is followed
 Accommodates 50% more worms
 Frequency of bed cleaning is reduced as ropes are
used.
 Labour saving is 60% in 4th and 50% in 5th instar
 Leaf saving is 25% in 4th age and 10% in 5th age
 3-dimensional feeding reduces leaf wastage
 Accommodates 50% more worms per unit area
39

Mounting and spinning
 5th instar lasts for 6 to 9 days based on season and races.
 Mature larva stop feeding
 Mature larvae is translucent, yellowish with empty stomach
 Moves restlessly in search for a suitable device(mountage) to spin a
cocoon.
 The process of picking ripe worms and putting on the mountage for
the formation of cocoon is mounting.
Proper time for mounting
 Silkworm body size is reduced to 1/3 of its size
 faeces are greenish and irregular.
 Worms raise their heads and thorax
 Crawl around the rearing bed for a suitable place for cocooning 40

41

SPINNING
 After passing out last excreta and starts spinning
 It swings its head in the form of S and 8 to
spin the cocoon
 The process of spinning takes 2 to 4 days
 Ideal temperature is 22 to 23 degree Celsius and relative humidity of 60 to
70% is required
Harvesting of cocoons
 Harvesting is separation of cocoons from mountages
 The silkworm larva metamorphosis into pupa inside the cocoon
 In course of time, the pupal skin hardens and turns dark brown
 Mountages are kept in slanting position to remove the cocoons from the
mountages
 The cocoons are harvested on 5th day in summer and on 6th day in winter
 It is kept in loosely packed bags and transported in cooler hours for marketing
in cocoons markets.
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ACKNOWLEDGEMENT
 Internet and sericulture textbooks by different authors
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Rearing techniques for successful cocoon crop.pptx

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