Breeding of WhangBoJama Sex-Limited Yellow Silk Silkworm Variety Suitable for Spring Rearing Season

A new silkworm variety "WhangBoJam" for spring rearing season is F1 hybrid between Jam317, a japanese strain bred from introduction breeding and Jam318, a chinese strain from introduction breeding. In the local adaptability test performed at 8 local areas in spring of 2012, the hatchability rate of WhangBoJam was recorded 95% similar to Kum HwangJam. The larval period was 8hours more long than KumHwangJam. The pupation percentage was recorded 6.6% higher than KumHwangJam. Single cocoon weight was recorded 2.29 g similar to KumHwangJam and cocoon yield(21.3 kg) was higher than KumHwangJam. The concentration of DNJ was measured to 0.22% in WhangBoJam, lower than DaePoongJam(0.26%). In the Paecilomyces tenuipes production ability test, the pupal weight of Whang BoJam was 1.33 g/individual, higher than KumHwangJam (1.19 g/individual).