Factors Influencing Cocoon Quality

This section presents the measures to be taken during silkworm rearing and mounting to obtain a better quality of cocoons with higher silk content, longer filament, better reelability and lower percentage of defective cocoons.

Temperature and Humidity During Mounting

Maintain temperatures at or near 25ºC and relative humidity around 65 percent for silkworms to spin good quality cocoons with a high reelability.

Mounting Device

Although different mount practices are employed among producer countries, rotary mounting frames provide good ventilation. The result is improved reelability of cocoons.

Harvesting and Handling of Fresh Cocoons

Cocoons should be harvested only following complete pupation. In practice, the appropriate harvesting day would be the fifth day in tropical countries, and the seventh or eighth day in temperate countries, from the mounting date. If premature harvesting takes place, the silkworm will still be in its larval stage, weigh more, have fragile skin, and could likely be crushed, which would cause stains to the cocoon during handling and transportation.