Comparative studies on the production of invasive larvae of Steinernema feltiae Filipjev nematodes within insect host

A comparative study has been made on the production of invasive larvae of Steinernema feltiae Filipjev within the cotton leafworm Spodoptera littoralis Boisduval and house fly Musca domestica Linnaeus. The results indicated that there is a positive correlation between the reproductive rate of invasive larvae and the initial dosages, host species and host stages. The reproductive rate of invasive larvae of Steinernema feltiae in Spodoptera littoralis imagos and caterpillars was higher than in M. domestica. At the pupal stages of M. domestica, no reproduction was obtained. Pupae were refractory to parasitism presumably owing to the effective protection afforded by the puparium. S. feltiae would be better adopted to live in S. littoralis than in M. domestica.