Sericulture, or silk farming, is the cultivation of silkworms to produce silk. The rearing starts with incubation of eggs. For healthy development and uniform hatching, the eggs are incubated under optimum temperatures of 250C and humidity of 80-85 per cent. They hatch in 10-12 days.
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 is produced by certain insect larvae to form cocoons. Silk is produced by several insects; but, generally, only the silk of moth caterpillars has been used for textile manufacturing.
Silkworms go through four stages of development. The feeding programme depends on the instar. The young worms should be fed young tender mulberry leaves.
The caterpillar eats for 26 days before spinning silk. It takes about three days to fully spin a cocoon and turn into pupa.
The caterpillar goes into stages until it reaches the fifth instar before it spins the cocoon. Our goal is to harvest the silk cocoon, therefore, we must dry them to avoid the development of pupa into adult, which will break silk yarn. The entire practice, from soil to silk, can be broadly classified into four interdependent agro-industrial activities:
- Mulberry farming for leaf production
- Silkworm rearing and cocoon production
- Production of raw silk (cocoon post-harvest technology)
- Weaving of silk fabric
To get good yield, the caterpillars need to be fed at least four times daily. For sustainability, it is important to have a plantation of mulberry.
In 26 days, you have quality cocoons, quality yarn and definitely you get good market price.
Sericulture potential in Kenya is associated with:
- Ideal climatic conditions for mulberry cultivation and silkworm rearing
- Silkworms can be reared in simple structures and equipment
- Availability of cheap labour
- Good cocoon quality with average filament length of 1200 meters
- No major cocoon pest
Basic Requirements to start up sericulture
- Land:This is the most important requirement for from it food for silkworms will be harvested.
2. Planting material: It is important to select varieties that bear many leaves, at least 30m tons per acre (good variety of Mulberry cuttings).
3. Silkworm rearing house: Must be one that can retain basic requirement of hygienic conditions.
4. Rearing equipment: Appropriate and approved rearing equipment such as rearing beds, mountages, sprayer pump, chopping boards etc are required.
5. Silkworm eggs: Must be obtained from approved silkworm egg breeders.
6. Training: A person intending to rear silkworms must have basic training of at least two weeks so as to master rearing techniques.
7. Farm equipment: Jembes, for digging and weeding, secateurs for pruning and harvesting of leaves, pruning saws for cutting larger shoots, fencing materials to prevent animal pests.
Stages of production
The stages of production are as follows:
- The silk moth lays 300 to 500 eggs.
- The silk moth eggs hatch to form larvae or caterpillars, known as silkworms.
- The larvae feed on mulberry leaves.
- Having grown and moulted several times, the silkworm extrudes a silk fibre and forms a net to hold itself.
- It swings itself from side to side in a figure ‘8’ distributing the saliva that will form silk.
- The silk solidifies when it contacts the air.
- The silkworm spins approximately one mile of filament and completely encloses itself in a cocoon in about two or three days. The amount of usable quality silk in each cocoon is small. As a result, about 2500 silkworms are required to produce a pound of raw silk.
- The intact cocoons are boiled, killing the silkworm pupa.
- The silk is obtained by brushing the undamaged cocoon to find the outside end of the filament.
- The silk filaments are then wound on a reel. One cocoon contains approximately 1,000 yards of silk filament. The silk at this stage is known as raw silk. One thread comprises up to 48 individual silk filament
Diseases that affect the worm are complex to treat and this is frustrating.
- One of the common diseases is flacherie, which attacks the worms when they eat infected or contaminated mulberry leaves.
To prevent it, farmers should observe hygiene and disinfect the rearing tray.
- Another disease is pebrine caused by a parasite. To prevent these diseases, a farmer is advised to observe hygiene and disinfect the rearing tray.