The Impact of the Surrounding Vegetation of Apple Orchards Under Ecological and Integrated Management on the Syrphids (Diptera: Syrphidae).

The study was conducted in south-eastern Poland, in three apple orchards where integrated pest management was applied, and in one ecological orchard and in their surroundings. In total, 1,677 individuals of Syrphidae belonging to 37 species, 21 genera, and two subfamilies were collected in the yellow traps. The most numerous were zoophagous syrphids - they constituted 94.5% of all the collected specimens and about 70% of the noted species. Among them, one species - Episyrphus balteatus (Deg.) - was the eudominant in the orchards and their surroundings. Comparing the occurrence of Syrphidae in the three IPM apple orchards and in their surroundings, it can be stated that more syrphids were caught in the boundary vegetation than within the orchards, whereas on the ecological site, more hoverflies were collected within the apple orchard than on the neigbouring plants. In most cases, in the orchard under IPM the syrphid species abundant in the surroundings of the orchards also appeared in great numbers in the orchards themselves, which indicated their movement from the boundaries into the orchards. The study has shown that the surroundings of orchards with species-rich, flowering plants positively influenced the species richness and the abundance of hoverflies occurring in the orchards. [ABSTRACT FROM AUTHOR]