[The secondary action of neporex on the pupa of parasitoids of stable flies].

In field tests for the control of house fly larvae in dung heaps of a pig fattening and breeding farm with Neporex SP 50 revealed, that the same species of parasitoids (Muscidifurax raptor, Spalangia nigroaenea, S. cameroni, Phygadeuon fumator) were capable to develop in cyromazine-damaged, larviform host puparia as in undamaged puparia. The parasitization rate is, however, about 3 times and the hatch of flies is twice as high in normal formed puparia compared with larviform puparia. Comparing the attractivity of untreated normal puparia with cyromazine-damaged, larviform puparia under laboratory conditions showed that the mentioned puparia gave rise to 2-3 times as much parasitoids. Rearing M. raptor and M. zaraptor on larviform host puparia in the laboratory led to a distinct decrease in the development of the parasitoid between populations within 3 ... 5 generations. Parasitoids emerged from larviform and from undamaged puparia showed not differences in their life dates in the F1 generation.