The occurrence of predatory mites (Acari: Phytoseiidae) in apple orchards of central Poland

Abstract: In 2011 twenty commercial apple orchards of Grójec district (mazowieckie, Poland) were sampled and examined for the presence of predatory mites. In ten of them T. pyri was introduced, while in the other ten predatory mites were not introduced before. Species composition and number of predatory mites was different depending on sampled orchard. Mainly two species were noted: Typhlodromus pyri Sheuten and Amblyseius andersoni (Chant). We sampled also one female of Neoseiuella tiliarum Oud. and one female of Neoseiulus callunae (Willmann), which we did not include in our data analysis. Predatory mites were present in both – in orchard where T. pyri was introduced in the past and in orchard where the predator was not introduced. In orchards, where predatory mites were released, the number of phytoseiids was three times higher than in orchards, where the predator was not released. A. andersoni was present in higher numbers in orchards, where T. pyri was released, which suggest that pesticides used in these orchards were selective to predatory mites.