Abstract
Silkworm strain that cocoons are reeled without using the boiling water may provide not only cost cut but also new material. It was clear that the water reeling strain which was bred in our laboratory was affected on the environment during the spining stage same as a general varieties, and it’s main factor was impossible to grope for fiber ends. We examined effect of humidity which affect the reelability on grouping end efficiency in the water reeling strains. N43 (from J 02, water reeling strain), N17 (from Daizo) and their Hybrid, N17×N43 were used in the experiment, 4 humidity conditions (low, midA, midB, high) were provided. The hybrid of N17×N43 was able to make cocoon at the experiment. On the other hands, 80% of N43 could not make cocoons and died without pupation at high humidity condition (99% RH). N17 which was another parent of hybrid was investigated in next raring season. Consequently, any larvae did not make a cocoon and some naked pupae appeared in N17. It may be suggested that hybrid larvae of N17×N43 made cocoons by heterosis at high humidity condition (99%RH).
