Silkworm Rearing and Management
Domain focus
Silkworm rearing and management tests the practical sequence from egg incubation to cocoon harvest, environmental control, feeding and mounting. It links rearing decisions to survival, cocoon quality and profit.
Core rules and concepts
- Use disease-free layings from a recognised seed source. Disinfect the rearing house, equipment and hands before brushing.
- Incubate eggs at about 25°C and high humidity; protect them from direct sunlight. Black-box treatment synchronises hatching in commercial batches.
- Young-age rearing (instars I–III) needs about 27–28°C and 85–90% RH with tender, chopped leaves. Late-age rearing (IV–V) needs about 24–26°C and 70–75% RH with mature leaves and good ventilation.
- Keep rearing beds clean, avoid overcrowding and feed at regular intervals. Handle moulting larvae gently.
- Harvest ripe larvae for mounting when they stop feeding and become translucent. Spinning takes about 60–72 hours; harvest cocoons after pupation and sort out defective ones.
Worked example
A rearer brushes 50 DFLs. Expected yield is 35 kg cocoons per DFL, so potential = 50 × 35 = 1,750 kg. If disease and mounting loss are estimated at 10%, expected harvest = 1,750 × 0.90 = 1,575 kg. Reasoning: first multiply DFLs by yield per DFL, then apply the loss percentage; this gives a realistic planning figure, not a guaranteed result.
Traps that cost marks
Using high humidity in late age; feeding tender leaves to fifth-instar worms; mounting before ripening; counting cocoons before sorting; ignoring ventilation.