- 1 Mulberry silkworm rearing
- 1.1 1. Preparation of rearing silkworm
- 1.2 2. Collection of race
- 1.3 3. Mating
- 1.4 4. Sterilization of eggs
- 1.5 5. Egg incubation
- 1.6 6. Larvae rearing I) Brushing: The process of transferring the newly hatched silkworm to rearing trays is called brushing. During brushing, the cards with the newly hatched silkworm are placed in the rearing trays and mulberry leaves cut into smallsquare (0.5 cm2) are sprinkled over the egg cards. The hatched silkworm crawled on to the tender leaves and start feeding. Later the cards are removed and any worm still left on the cards are tapped on therearing tray.
- 1.7 7. Ripening, spinning and cocoon formation
- 1.8 8. Cocoon harvesting
- 1.9 Disease and Pest of silkworm
Mulberry silkworm rearing
Sericulture is an agrobased industry and it deals with mulberry culture and silkworm rearing. The rearing of silkworm involves the following steps
1. Preparation of rearing silkworm
2. Collection of race
4. Sterilization of eggs
5. Egg incubation
Leave the eggs at 22to 26 C temperature and 80to 85% relative humidity in an
incubator for incubation. In order to obtain uniform laying eggs at the blackhead stage are kept in black boxes on the day prior to hatching. In this way, the early maturing embryos are prevented from hatching and the late maturing embryo given time to develop and catch up with the early maturing ones. The next day, they are exposed certainly to diffused light so that the larvae has uniformly in response to the phototrophic stimulus. By this method, hatching of 90% and over can be obtained in one day.
6. Larvae rearing
I) Brushing: The process of transferring the newly hatched silkworm to rearing trays is called brushing. During brushing, the cards with the newly hatched silkworm are placed in the rearing trays and mulberry leaves cut into smallsquare (0.5 cm2) are sprinkled over the egg cards. The hatched silkworm crawled on to the tender leaves and start feeding. Later the cards are removed and any worm still left on the cards are tapped on therearing tray.
During 4th and 5th instar, the bed should be cleaned once a day in the morning. For cleaning purpose, usually nets are used. The net is spread over the bed and one
feeding is given before the nets are lifted and transferred to a fresh clean tray. The
worms crawl through the meshes in the net and come up to feed on the leaves on the
nets. If the worm are healthy, particularly all the worm will come up leaving the old
leaves litter behind on the old trays which are cleaned later. The mesh size of the net
used for the different instar are as follows
vigorous and full growth of silkworm. As the worm grow in weight and size. The
density in the rearing bed increases and condition of over crowding are faced. It is therefore, essential that the density of population in the rearing bed should be regulated.
The spacing to be provided for different ages of silkworm is given below
countries, they are influenced by nature wide delicate and very sensitive to
environmental condition. Among the various environmental factors that influence the
silkworm, the most important are
different instars are given below
light should not be too bright.
Air: Silkworm required fresh air for their various physiological functions. So proper ventilation should be provided.
7. Ripening, spinning and cocoon formation
6to 7 days after the last mould and in this time they completely cease feeding. Pick the larvae in time and place them in chandrika to facilitate undisturbed spinning cocoon
8. Cocoon harvesting
after 56 days and then dry immediately in oven at 70-80 C for 24 hours or in the sun.
Disease and Pest of silkworm
rearing surroundings with 2% formalin. ♦During rearing, unequal size worms and faecal matter should be microscopically
examined for the presence of pebrine spores and if observed, larvae, cocoons and laying should be collected and burnt or buried. ♦In the grainages, scientific methods of mother moth examination should be employed♦ Surface sterilization of the eggs with 2% formalin for 5 minutes.
association. Depending on symptoms and cause they are called as bacterial flacherie disease,
septicemia, sotto disease, etc. The disease may occur due to fluctuations in temperature, humidity and feeding poor quality mulberry leaves.
(22-25°C) and humidity (80-85%) during incubation of eggs. ♦ Attend thorough disinfection of rearing room, appliances and surroundings.
Cytoplasmic polyhedrosis (CPV) and infectious flacherie. Nuclear polyhedrosis (NPV) is a major viral disease in silkworm. It is caused due to the presence of high temperature, high humidity and feeding of poor quality mulberry leaves. It is highly infectious.
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