Occurrence of hazelnut pests in southeastern Poland

In Poland, the cultivation of large-fruited hazelnuts (Corylus avellana L.) is not common, but has gained popularity since the 1980's. The production area is constantly increasing and now hazelnut is grown on 1000 ha, mostly in southeastern Poland. Properly cultivated plantations give average yields of 1.5 to 2.0 or even up to 3.0 tons of hazelnuts per hectare. The aim of this research was to characterize the species composition of the fauna of hazelnut pests in three ecosystems formed by man to various degrees. Data was gathered at 14-day intervals during three growing seasons (1994-1996) in three ecosystems: a protected hazelnut plantation, an unprotected plantation where no chemical treatment or horticultural techniques were applied, and on shrubs of common hazel in the forest. Ninety-one insect and mite species were found. The factors;affecting the occurrence of hazelnut pests were environmental conditions, cultural practices and efficacy of chemical treatments. In the protected plantation, aphid species (Myzocallis coryli and Corylobium avellanae), scale insects (mostly Parthenolecanium corm) and mite species (mostly Phytoptus avellanae) occurred in the greatest number. In the unprotected plantation and on common hazel growing in forest, a greater number of pest species was found, including Operophtera brumata, Strophosoma capitatum, Haltica brevicollis, Apoderus coryli and Deporasus betulae. Other factors that affect the occurrence of hazelnut pests in the three ecosystems are discussed and a list of all pests is included in this paper.