Parazitické blanokrídlovce (Hymenoptera) na larvách podkórnika dubového (Scolytus intricatus Ratz., Coleoptera: Scolytidae)

The purpose of the paper was to determine the species composition of parasitic wasps (parasitoids) and to find out the percentage of parasitization of the European oak bark beetle (Scolytus intricatus Ratz.) larvae. Parasitoids were gathered by means of photoeclectors from 96 samples of Quercus dalechampii Ten. and from 96 samples of Quercus cerris L. Logs were sampled in eight forest stands in the surroundings of Tren ín and Bánovce nad Bebravou (western Slovakia) during two years (2006 and 2007). Altogether we determined 14 species of parasitoids belonging to four families (Braconidae, Eurytomidae, Pteromalidae, Eulophidae). The Eulophidae chalcidoid wasps predominated whereas of them the chalcidoid wasp Entodon leucogramma was the most important natural enemy of the European oak bark beetle (dominance 45.7% in 2006 and 54.1% in 2007 of all parasitoids emerged). The braconid Dendrosoter protuberans was the second most dominant species (dominance 13.7% in 2006 and 24.2% in 2007 of all parasitoids emerged). Larvae of the European oak bark beetle developing in the logs of Quercus dalechampii were parasitized more heavily than those in the logs of Quercus cerris (average parasitization rate 25.7-32.7% vs. 18.4-24.5%, respectively). Larvae were more parasitized in 2006 than in 2007 (27.0-33.4% vs. 17.2-23.8%, respectively). The paper presents an overview of parasitoids of the European oak bark beetle, which represent one of the most important bioregulative factors in its populations.