Question

20 lines on rearing of silkworm​

Answer 1

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Mulberry silkworm rearing, being completely domesticated, demands specified environmental conditions like temperature (24-28 C) and relative humidity (70-85%).  It is therefore necessary to evolve measures for economic cooling through selection of proper material for wall and roof fabrication, orientation of building, construction method, design, etc.  Further, enough space must be available to carry out leaf preservation, chawki rearing, late age rearing and moulting.  It should also be convenient enough to conduct effective cleaning and disinfection.

The size of the rearing house depends upon the quantum and type of rearing.   A floor area of 400 sq ft. can provide rearing space for 100 dfls (dfl: Disease Free Layings; 1 dfl = 500 larvae)

Rearing appliances

The late age silkworms do not tolerate high temperature, high humidity and poor ventilation. Hence, the rearing house should have cross ventilation facilities to bring down the room temperature and for removal of vapour and harmful gases generated from large quantities of excreta produced by silkworms. The minimum requirement of equipments for 100 dfls (50,000 larvae) is given in Table .

Table : Rearing appliances required for rearing 100 dfls (50, 000 larvae)

Sl. No.ItemQuantity1Shoot rearing rack (40’ x 5) 5 tiers12Rotary mountages or chandrike353Power sprayer14Hygrometer1

Disinfection

Disinfection of rearing house and appliances should be made twice before rearing that is once with 5% bleaching powder (immediately after the completion of previous crop) and another time with 2.5% Sanitech (Chlorine di-oxide) solution just 2 days before the next crop.