The document provides information about the life cycle and rearing process of silkworms. It discusses the identification of ripened worms, different mounting methods to transfer worms to frames for cocoon spinning, factors to maintain ideal environmental conditions during spinning, and harvesting of cocoons. The key stages covered are mounting mature silkworms using various techniques like picking, self-mounting, or shaking shoots; maintaining temperature, humidity, and ventilation during spinning; and harvesting cocoons 5-7 days after the start of spinning.

2. Contents
Introduction
Identification Of Ripened Worms.
Mounting- Mountages
Mounting Methods
• Quality Of Mountages
Types Of Mountages
Care During Spinning
Harvesting

3. INTRODUCTION
• The life cycle of silkworm can
be broadly divided into egg,
larvae, pupa and moth .
1. Multivoltine Type 45-50 Days
2. Bivoltine Type 50-55 Days
• Larval period is the only
feeding period.
• It is a preparatory stage
where the animal stores the
food material for future life
stages and also develops
certain organs which can
protect the successive stages
(pupa) by enclosing it.

4. • The larvae develops a pair
of silk glands which are
modified labial glands, and
are capable of utilizing the
haemolymph amino acids
for the synthesis of silk
proteins.
• These proteins (sericin,
fibroin) are utilized by the
mature larvae for spinning
the silk cocoons.
• At the end of fifth instar
the larva stops feeding and
starts spinning the cocoons
by oozing silk from the
spinneret and wraps itself
for undergoing into pupa
stage

5. IDENTIFICATION OF
RIPENED WORMS
• After eating sufficient
mulberry leaves in 5th
instar , on 6th-7th day,
The silkworm loses
appetite & stops eating.
• Skin becomes
translucent; yellowish in
colour,raises its head.
• Begins to look in search
of a suitable place worms
move towards the
periphery of the rearing
trays in search of
anchorage
Feeding worm

6. Mounting- Mountages
The mature
silkworm larvae are
then transferred
to a suitable place
with proper anchor
for spinning
cocoons, called as
Mountages .
The process of
transferring the
mature larvae is
called Mounting.

7. Mounting Methods
Picking up and mounting
self mounting method
Shoot shaking method

8. Picking up and Mounting
• Commonly used by south Indian farmers,
picking of individual matured larvae by hand
and mounting on the Mounting frames.
• Help to produce good quality cocoons.

9. Self Mounting Method
Let mature silkworm up
into the cocooning
frames placed on the
rearing bed is called
self mounting or natural
mounting.
Cocooning frames are
left on the bed for 4 -
6 hours and mature
worms are allowed to
crawl up on the
mountages due its
negative geotropic
nature

10. Shoot shaking method-Jobarai
method
• When more than 30% worms
are matured ,10 to 12
mulberry shoots with mature
silkworm from the shoot rack
can be taken out and shaken ,
so all the larva fall down on
the sheet which spread on
the floor.
• Extra leaves, faeces etc..
removed by hand and worms
be mounted on the cocooning
frames.
• Saves time and labour
without affecting the cocoon
quality.

11. Quality of mountages
• It should be convenient for mounting with
sufficient and uniform cocooning space.
• Material used should absorb moisture caused
due to excretion of urine.
• Material should be cheap, durable and easily
available locally.
• It should be amenable for disinfection.
• Easy for cleaning and storage after use.
• Cocoon harvesting should be easy.

12. TYPES OF MOUNTAGES
Traditional Bamboo
Mountages
Plastic Collapsible
Mountages
Rotary Mountages
Bottle Brush
Mountages
Mulberry Twigs /
Grasses / Straw
Modified ( Hybrid )
Mountages

13. Traditional Bamboo Mountages
chandrike
• Bamboo strips are fixed in a
spiral/circular
fashion on the bamboo mats.
• The idea size of the
mountage is 1.8 x 1.2 meters and gap
between the
spirals should be 5 to 6 cms.
• 40 to 60 larvae per sq. ft.
can be mounted.
• During spinning stage, two mountages
placed one behind the other at an
inclination of 45,
this reduces the number of bad or
rejected cocoons.

14. Plastic collapsible mountages
(Netrike)
• Standard size 90x60cm (3’ x 2’ft)
• Can accommodate 300 – 350 larvae

15. Merits
• Lighter in weight
• Less space for storage
• Easy to handle and disinfect
Demerits
• Loses size, shape and corrugation
• Easily damaged by rodents

16. Rotary Mountages
• Size 55 cm x 40 cm
• Each set accommodate
1560 larvae
Advantages
• Uniform size and shape
• Defective cocoons are less
• Easy - harvesting -
Storage and disinfection
• Higher reelability and
improved reeling
parameters

17. Bottle Brush Mountages
• Made of either Bamboo or Plastic
• Can accommodate 450 – 500 worms
• Life span 3 – 4 years for bamboo and
10 years for plastic mountages

18. Merits:
• Urinated cocoons are minimum
• Easy to disinfect, mount and harvest
• Improved cocoon quality and reelability .
Demerits:
• Initial investment is high
• Not popular among farmers

19. Mulberry Twigs / grass / straw
• Mulberry, mango and red gram twigs are
used.
• Double cocoons are more.

20. Merits:
• Mounting and
harvesting is easy
• Defective cocoon 2 –
5 %
Demerits :
• More space for
mounting

21. Shoot Rearing Rack Rotary
Type Mountage
• To facilitate accomodation of mountages
within the shoot rearing rack itself.
• Save -75% space -25% labour

22. Thalaghattapura Ribbon
chandrike
• Self-mounting
• Doesn’t require separate
device for harvesting –
easy
• Saves 50% investment
on mountage, 60%
expenditure on labour
• Fabrication is easy
• Easy disinfection
• Less space for storage

23. CARE DURING SPINNING
Environmental Conditions -Temperature :
• Worms during spinning require a slightly higher
temperature than rearing
• Too high a temperature will compel the worms to spin
in haste and thus waste a lot of silk
• Too low a temperature, causes delay in the spinning
and affects the colour, lustre and texture of cocoons.
Also, the cocoons will not be so compact.
• Too high a temperature make the filament thicker,
and too low a temperature, to make it thinner.
• Violent fluctuation leads to ununiformity
• Around 24°C is quite ideal for spinning.

24. Relative Humidity:
• RH at the range of 60 to 70 per cent is ideal.
• Too much moisture affects the luster of the
filament.
• From the point of view of reeling, drier the air
during mounting the better it will be, but too
great a dryness debilitates the worms and is to
be avoided.
• Ventilation is an essential point for attention as
a good deal of moisture has to be got rid of and
there is also a good deal of excreta-solid, liquid
and gaseous.

25. CARE DURING SPINNING
• Mounting room requires moderate, even
illumination. Strong light causes crowding of
silkworms at one side and finally results in double
cocoons or uneven thickness cocoons.
• Complete darkness will slow down the spinning
process resulting in low quality cocoons.
• Ants crawling on to the mountages are
prevented.
• Spinning worms if disturbed increases floss
percentage

26. Syncronisation of spinning
• Sampoorna is a spinning hormone of
plant origin which contains
β-ecdysone.
• Application of this hormone ( 20 ml
in 4 liters water on the onset of
spinning when 3 - 5 % mature worms
are noticed in a batch is required
for 100 dfls ) on the last feed will
hasten the maturation process and
induces synchronised spinning.
• lt reduces mounting period by 18 -
40 hours.
• This technique additionally helps to
overcome unforeseen shortage of
mulberry leaf if any in the final
instar and out break of diseases in
the fifth instar.

27. Spinning/ Cocooning
• After mounting the ripen
worms sticks on to the
mountages by oozing out
the silk fluid which will
harden immediately after
coming in contact with air
and sticks itself to the
mountages.
• It starts to ooze out the silk
by continuous movement of
its head in a very specific
manner to form the silk
filament .

28. • Larvae moves its head continuously about 70-
80 times per minute till the compact shell
called cocoon is formed and detaches itself
from the last layer of silk of then transforming
into pupa.
∞
Ș

29. The Cocoon will have three layers.
• Outer floss- not reelable
• Middle compact layers -reelable
• Inner pelade- not reelable

30. Harvesting
• MV- Spinning Completes on 3rd to 4th day –
harvesting on 5th day.
• BV- Spinning Completes on 4th to 5th day –
harvesting on 6th to 7th day.

31. • Harvesting should not be done
immediately after pupation.
• Further, harvesting should be done
before the moth emerges out.
• Too many days delay in harvesting
will result in formation of pierced
cocoons due to emergence of adult
moth

32. Cocoon Harvester:
• It is made up of iron or
wood.
• It consists of two parts and
is usedfor harvesting
cocoons from rotary
mountages.
• Cardboard Mountages are
inserted into the wooden
frame and cocoons are
pushed out using the
pusher made of the same
size as the holes of the
Mountages.

33. • Thank you