The parasitisation of the rose tortrix [Archips rosana (L.)] Population in the apple orchard in the Wielkopolska region, Poland

The rose tortrix is a polyphagous species, which is dominant in the leafroller complex (Tortricidae) in orchards, including apple orchards and fruit-bearing shrubs in western and southeastern Poland. Rose tortrixes massively feed on leaf rosettes, developing leaves, buds, flowers and fruit buds in orchards. The population of this phytophage is regulated by environmental factors such as its natural enemies, e.g. parasitoids. The aim of the study was to determine the degree of parasitisation of rose tortrix pupae and to determine the role of individual families of parasitoids in reducing their population. The study showed that parasitoids from the Ichneumonidae, Chalcididae, Tachinidae, Euliphidae and Pteromalidae families reduced the rose tortrix population. The parasitoids of the Ichneumonidae family were the most effective entomophages. The degree of total parasitisation of rose tortrixes in individual years of the research was similar. The effectiveness of these entomophagous parasitoids is influenced by environmental factors – above all by weather conditions, the number of crop protection treatments and the ecological infrastructure of orchards.