Silkworm Seed/Egg production
Disinfection of grainage and implements
- Bamboo made house with thatched roof and mud-plastered wall is preferable for grainage.
- Disinfect the grainage rooms and appliances prior to commencement of operation.
- Wash the rooms and appliances with 5% bleaching powder solution before one day.
- Dry the appliances in sun shine for 3-4 hours before one day.
- Disinfect the rooms and appliances with a mixture of 2% formalin, 0.5-1% lime and 0.5% detergent solutions @ 1L/ sq.m after one day.
- Separate out the melted, flimsy and good cocoons.
- Take out the gut portion and observe under microscope.
- Reject the lot in case there is incidence of pebrine.
- Disinfect the contaminated room before the arrival of new lots.
Preservation and protection of seed cocoons
- Immediately after the receipt of seed cocoons, spread them on trays in a single layer to facilitate good aeration.
- Reject the seed cocoons which are melted, uzi infested, flimsy and not conforming to the characteristics of parent races.
- Preserve only the healthy seed cocoons in trays for further processing.
- Provide cross ventilation in the preservation room.
- Maintain temperature at 25 ± 1˚C, relative humidity of 75 ± 5%, 16 hour light and 8 hour dark conditions in the cocoon preservation room.
- Maintain complete darkness one day prior to emergence to avoid irregular emergence of moths.
Early eclosion/ artificial eclosion/ forced eclosion of moths
- This helps in determining the disease freeness of a batch and helps in minimizing the loss to grainage.
- For early emergence of moths, 50-60 seed cocoons are taken from individual lots and placed into an artificial eclosion box.
- Maintain the temperature at 32-33 0C with the help of thermostat. This accelerates the development of pupae and moth emerges early.
- Examine the early emerged female moths of respective lots are under microscope to know the disease freeness of lots.
Synchronization of emergence of moths, pairing, depairing and oviposition
- Keep the cocoon preservatio0n room dark before the expected day of emergence of moths.
- In case of variation in development of male or female pupae, the development of male pupae can be arrested by preserving them at 5-7 0C and 75 + 5% relative humidity for 3-4 days.
- Only healthy and active moths are taken for pairing.
- After 1-2 hours of emergence, the male and female moths of respective combination are allowed for 3.5 to 4 hours of pairing.
- At the time of depairing, the male and female moths are to be moved side way so that the moths are separated easily without causing injury to reproductive organs.
- The mated female moths are taken in a separate container and induced for urination.
- Moths are placed on egg sheet and covered with cellules and kept in semi dark condition for oviposition.
- Under proper preservation (5-7 0C), male moths can be used for second pairing by giving 1-2 hours rest.
- Throughout the process of pairing, depairing and oviposition, optimum temperature of 25 ± 1 0C and relative humidity of 75 ± 5% should be maintained.
- Examine the mother moth either individually or in mass for pebrine disease.
Surface sterilization of eggs
- Dip the egg sheets in 2% formalin for 10-15 minutes. This helps in removal of pathogens adhering to the egg shell and further prevents secondary contamination.
- Wash the eggs in formalin solution. It helps in firm adherence of eggs to the sheet.
- Maintain temperature of 25 ± 1˚C, relative humidity of 75 ± 5%, 16 hours of light and 8 hours darkness.
- During the pinhead stage or before two days of hatching, maintain total darkness for uniform development of embryo and hatching of larvae at a time on a single day.
- Directory of Sericulture Technology 2008, Karnataka State Sericulture Research and Development Institute, Bangalore- 5 60 062.