Standortabhängiges Parasitierungsverhalten von Gegenspielern der Roßkastanienminiermotte (Cameraria ohridella) in Berlin

The parasitism of the horse chestnut leaf miner (Cameraria ohridella) in the city of Berlin is currently being studied within the project BerlinCam. The project involved intensive field studies at 7 horse chestnut stands in different types of habitats, spanning three vegetative periods, to understand the influence of abiotic and environmental factors on parasitoid complexes and para- sitism rates. 16 species of parasitoids have been determined so far, most of them generalistic mem- bers of the chalcidoid family Eulophidae. The parasitism rates as well as the numbers of parasitoid species were, on average, lower in 2004 than in 2003, which may be a result of different weather conditions in these two years. Surprisingly, the highest rates of parasitism were measured along streets in the city centre, whereas they were significantly lower at semi-natural stands outside the city. Several environmental factors, like the presence of other leafminers in the surrounding vegeta- tion or the population density of C. ohridella at the locations may be responsible for these results.