Abstract
To shorten the labor cost for the production of the fungus, Paecilomyces tenuipes, the use of uncocooning mutant silkworm as a host was examined. The strain Nd was selected as the best for the production of P. tenuipes among five strains (Nd, NdH, p3Nd, Nd-s and Nd-t). Nd yielded the highest pupation rate of 95%, naked pupation rate of 99% and pupal weight of 1.4 g/individual. The optimum time for the infection of P. tenuipes was 12 h at 28.5°C and 95% R.H., when 108 conidia/ml of P. tenuipes were sprayed on the surface of the silkworms. The yield of P. tenuipes was reduced when Nd was used as a host because Nd was smaller than the hybrid Baegokjam that has been used as a typical host. To increase the host weight, Nd was crossed with Jam123 or Jam124, and resulted in not only greater weights (>1.2×) but also higher yield (>1.5×) of P. tenuipes.
