Japanese

Japanese silkworm lines are domesticated Bombyx mori strains shaped by centuries of Japanese sericulture and later by formal breeding stations. The term covers many lines rather than a single breed. Some traditional Japanese races are associated with pale larvae and white or yellow-white cocoons, sometimes with a slightly constricted or peanut-like shape, but traits depend on the strain. Selection has emphasized hatch timing, cocoon uniformity, filament quality, and usefulness in planned hybrids.

These silkworms are kept by commercial breeders, research collections, schools, and hobby rearers who can provide mulberry through the larval period. Eggs and young larvae are sensitive to temperature swings and contamination, so small batches are usually raised in clean trays with frequent leaf changes. Japanese lines are often crossed with Chinese lines to combine complementary cocoon and vigor traits. If maintaining a named strain, separate breeding and careful labeling matter, because adult moths mate readily once they emerge.

Colors: White, Yellow-White