Muga is reared outdoors on standing trees, so the rearing field cannot be sealed against disease or predators the way an eri rearing house can. Everything below is an attempt to close that gap by preparation rather than containment — which is why the pre-brushing week matters more here than in any indoor system.
Pre-brushing preparation
- Plot: shady in summer, sunny in winter, on plants carrying quality foliage; drain all stagnant water.
- Tree cleaning, 5–10 days ahead: clear ant nests, spider nets and insect pests; remove dry twigs and leaves; clean the basal area. Grass beneath the plants need not be removed.
- Canopy spray: 2 % bleaching powder solution, twice at 3–4 day intervals.
- Ground dusting: slaked lime and bleaching powder at 9:1, @ 200 g/m², twice at 3–4 day intervals.
- Netting: erect nylon net 1–2 days before brushing, leaving space for aeration.
- Appliances: disinfect in 5 % bleaching powder solution and sun-dry until odour-free.
Sodium hypochlorite schedule
For one acre carrying 400 dfls, per crop.
| Application | Sodium hypochlorite (L) | Water (L) |
|---|---|---|
| 7 days before brushing | 1.0 | 200 |
| 2nd instar (once) | 0.5 | 100 |
| 3rd instar (once) | 0.5 | 100 |
| 4th instar (twice) | 1.0 | 200 |
| 5th instar (twice) | 1.0 | 200 |
| Total | 4.0 | 800 |
Brushing and crop management
- Brushing: spread tender leaves over newly hatched larvae so they settle; transfer with the leaves early morning — away from sun in summer, towards it in winter; avoid overcrowding.
- Trunk banding: wrap each trunk to 2–2.5 ft with polythene or banana sheath to stop larvae descending and ants ascending.
- Age-wise rearing: light pruning or defoliation three months ahead supplies tender leaf to the third instar at about one dfl per young plant; late-age worms go onto semi-mature to mature foliage.
- Stocking: 1–1.5 dfls on a 3–7 year old plant; 3–4 dfls above 7 years; 2,000 dfls per hectare per year in two seasons.
- Handling: transfer by cutting twigs; use bamboo forceps for dead and diseased larvae; keep 5 % bleaching powder solution and fresh water at the site for hand sanitation.
- Sanitation: bury diseased, dead and undersized larvae in a pit 1.5 ft deep away from the field, dusted with 9:1 slaked lime and bleaching powder.
- Seasonal care: lift the net by day in summer and close it before dusk; use smoke morning and evening in winter.
- Maturity: ripe larvae crawl down the trunk of their own accord and must be collected promptly.
Mountage
| Criterion | Box-type bamboo mountage | Jali / collapsible plastic |
|---|---|---|
| Escape of mature larvae | Prevented | Common |
| Spinning | Uniform | Uneven |
| Capacity | 500 – 600 worms per box | 250 worms per tray |
| Harvesting time and space | Less of both | More of both |
| Service life | Durable, reusable after disinfection | Shorter |
The institute’s box-type bamboo mountage (2003) is reusable for five years and occupies 5.82 cft per 1,000 worms against 96 cft for the traditional jali. Benefit–cost ratio 1.5 : 1.