ON THE PARASITIZATION OF THE PEAR LEAF BLISTER MOTH, LEUCOPTERA-MALIFOLIELLA (COSTA) (LEP, LYONETIIDAE) IN THE FRUIT-GROWING AREA HAVELLANDISCHES-OBSTBAUGEBIET

A total of 16 parasitoid species had been reared from larvae and pupae of the leafmining host. They belong to the families Eulophidae (11), Pteromalidae (2) and Braconidae (2). The species are listed in systematical order. Additional informations about bionomics and rearing experiences are included. Chrysocharis nitetis Walk. is the most frequent parasitoid of the larvae. The parasitization had been investigated in sprayed and unsprayed orchards as well as in abandoned localities, distributed over the whole region. The percent parasitism rate was very low at all sites in the first generation. In contrast to the summer time the parasitoid induced mortality reached high values in the second generation, often exceeding 50 %. These alternating levels of parasitization between the generations turned out to be stable during 3 successive years of the research period. In sprayed orchards the parasitization of the host populations remained generally low-during all the time. All the identified species are polyphagous parasitoids, and thus not restricted to single habitats. Consequently, the host - parasitoid interaction must be considered on a much wider spatial scale, including landscape elements outside the orchards.