The Importance of Parasitoids in Apple Orchards

Abstract

ABSTRACT Sixty seven parasitoid species have been reared from leaf miners (Phyllonorycter blancardella Fabr., Ph. corylifoliella Haw., Leucoptera malifoliella Costa, Nepticula malella Stt.) and leaf rollers (Adoxophyes orana F.v.R., Pandemis heparana Den. et Schiff., Archips rosana L.). The lowest number of parasitoid species occurred in the conventional orchard, while the highest number were found in the integrated and in the untreated ones. The most important parasitoid species were Sympiesis sericeicornis Nees, S. gordius Walk., Pnigalio pectinicornis L., P. soemius Walk., Holcothorax testaceipes Ratz., Chrysocharis pentheus Walk., Pediobius pyrgo Walk., Tetrastichus ecus Walk., Achrysocharoides atys Walk., Baryscapus galactopus Ratz., Neochrysocharis chlorogaster Erd. (Chalcidoidea), Pholetesor bicolor Nees, Macrocentrus pallipes Nees and M. linearis Nees (Braconidae). The larvae and pupae of leaf miners were parasitized to 35–45%, occasionally to 80%. At the same time the larvae of leaf rollers were parasitized only to 10–20%, seldom to 30–40%. The difference in species composition and in the efficiency of the parasitoids depends on the population density of the host, on the type and intensity of the treatment of the orchard, and on the character of the surroundings.