Comparative studies on the development of the entomogenous nematodes Steinernema feltiae Filipjev on Spodoptera littoralis (Boisduval) and Musca domestica Linneous.

Comparative studies were made at 26 degrees C under laboratory conditions on the development of Steinernema feltiae Filipjev (= Neoaplectana carpocapsae) on the different stages of Spodoptera littoralis (Biosduval) and Musca domestica (Linneous). In the present investigation the host species influence manifested itself, in a quicker development rate along with the cotton leafworm S. littoralis. Particular development stages took place earlier in the S. littoralis than in M. domestica. As far as the occurrence dates of particular stages of S. feltiae were concerned, the differences in relation to the two host species were significant. The changes in numbers of giant forms in the development course of populations in the caterpillars, pupae and imagos body of both species were studied. The numbers of giant forms correspond with the numbers of invasive larvae, it seems that at first they are growing and then decreasing.