S. Mahunka szerk.: Folia Entomologica Hungarica 57. (Budapest, 1996)

Macrocentrus pallipes, were present in the mixed and the pure old oak forests either at Csobánka or at Gödöllő and, finally, nine species ( Aleiodes circumscriptus, Ascogaster varipes, Cotesia tibialis, Leiophron apicalis, Macrocentrus collaris, Microchelonus contractus, Phanerotoma fracta, Zele albiditarsus) were trapped in a proportion 5:4 at Csobánka and Gödöllő either in the mixed or in the pure old oak forest. These ten braconid species are considered as more or less permanent in their annual phenology having at least two generations in one year and, thus, more or less permanently present in our three years of trappings in June and August of 1992-1994. b) The rest of the braconids, i.e. 39 species, has been trapped much less regularly, usually in a specimen numbers 1 to 3 and mostly sporadically in the annual samplings. From among the 39 species two ones, Dendrosoter protuberans (parasitoid of xylophagous beetles) and Diospilus capito (parasitoid of Anobium and Ceutorhynchus beetles), display some kind of interest: the first species was trapped only at Csobánka in the mixed oak forest in all three years in 3, 2, 3 and in the pure oak forest 1992 and 1993 in 3 and 7 specimens, respectively; the second species was trapped only at Gödöllő in the pure oak forest in all three years in 3, 2, 2 specimens, respectively. The results of diversity indices, the cluster analysis and rank correlation of the braconid communities of the different oak forests showed there is relationship between the structure of the different forest types and the structure of the braconid communities. The upper relationship was confirmed by the higher values of the number of species and diversity indices of the braconid communities in the mixed oak forest and in the canopy of mixed oak forest at Csobánka than the same in the pure oak forest or in the young oak forest. The reason of changes of the structure of the braconid communities from the mixed oak forest toward young oak forest is the cutting of the tall trees. Acknowledgements — In the collecting of the braconids (and other insects too) our good colleague, Dr. Gy. Sziráki (Hungarian Natural History Museum, Budapest) was of great and essential help to us. His friendly assistance is highly appreciated and sincerely thanked. Also we should like to express our sincere thank to our assistants, Mrs Mónika Ladár, Mrs Katalin Horváth and Mrs Annamária Szilágyi, for their helpful co-operation in the field-work and in the laboratory. Our sincere gratitude should go to the Board of the Hungarian Scientific Research Fund (OTKA) whose financial support rendered it possible to realise our project. LITERATURE Fekete, G. (1965): Die Waldvegetation im Gödöllőer Hügelland. — In: Die Vegetation Ungarischer Landschaften, Band 5. Verlag der Ungarischen Akademie der Wissenschaften, Budapest, 223 pp. Kuno, E. (1991): Sampling and analysis of insect population. —Annu. Rev. Entomol. 36: 285304. Ludwig, J. A. and Reynolds, J. F. (1988): Statistical ecology. A primer on methods and computing. A Whiley-interscience publication. John Wiley & Sons, New York, 337 pp. Morris, M. G. (1974): Oak as a habitat for insect life. — In: Morris, M. G. and Perring, F. H. (eds): The British Oak: its History and Natural History. Faringdon, pp. 274-297. Norusis, M. J. (1986): SPSS/PC+ for the IBM PC/XT/AT. Papp, J. (1994): The dispersion of braconid wasps in an oak forest of Hungary. (Hymenoptera: Braconidae). — Folia ent. hung. 55: 305-320.