S. Mahunka szerk.: Folia Entomologica Hungarica 55. (Budapest, 1994)

FOLIA ENTOMOLOGICA HUNGARICA ROVARTANI KÖZLEMÉNYEK LV 1994 p. 305-320 The dispersion of braconid wasps in an oak forest of Hungary (Hymenoptera: Braconidae)* J. Papp The dispersion of braconid wasps in an oak forest of Hungary (Hymenoptera: Braconidae). - Within the botanical exploration "Síkfőkút Project" four Malaise-traps were set up in the Síkfőkút oak forest, three in the forest and one in the meadow near to the forest in order to obtain, besides other insects, an assemblage-pattern of braconid wasps. In the forest the traps collected the braconids in the following plant layers: herb-shrub (0-3 m), canopy (12-14 m) and above canopy (25-27 in). Altogether 326 specimens belonging to 60 species had been collected. Four species, Ascogaster grahami, A. varipes, Earinus elator and Homolobus truncator, proved to fly fairly permanently during the vegetation period of 1987; the majority of the species, 56 species, flew sporadically in the same period (Table 1, Figs 1-4). The analysis of the braconid species-components of each plant layer shows that the richest in braconids was the herb and shrub layer with 43 species, the second in line was the meadow with 22 species; the canopy yielded 19 species, while the layer above the canopy gathered 14 species. The phenology of the braconid species is summarized in a graphic form (Fig. 5). INTRODUCTION Within the frame of the "Síkfőkút Project" a phyto- and zoocenological investigations had been managed and carried out by the Kossuth Lajos University at Debrecen. The Síkfőkút oak forest is situated in the North Hungarian Mountains, 6 km NE from the town Eger and in the vicinity of the village Noszvaj, and, furthermore, lies at an altitude of 320-340 m above sea level. The forest is one of the characteristic plant communities of the Pannonian region namely the Turkey oak- sessile oak forest or Quercetum petraeaecerris association. The forest in question is about seventy years old where three well-discernable plant layers: the canopy formed by the trees, shrub and herb layers may be distinguished. Dominant species in the layers are Quercus petraea (84%) and Qu. cerris (15%) in the canopy rising in height to about 18-20 m; Acer campestre, A. tataricum, Cornus mas, C. sanguinea, Quercus petraea, Ligustrum vulgare and Euonymus verrucosus are the most significant components in the shrub layer rising in height to about 1-4 m; and Poa nemoralis (63%), Melica uniflora (19%), Carex michelii, C. montana, Dactylis polygama, Festuca heterophylla, Galium schultesii, Fragaria vesca, Lathyrus vernus, L. niger, Chrysanthemum corymbosum (all below 16%) form the herbaceous layer (Jakucs 1985). Concerning the braconid wasps living in the Turkey oak-sessile oak forest the main goal of the investigation was to obtain an insight of their dispersion in the plant layers * The elaboration of this material was supported by the Hungarian Research Fund (OTKA) No. T-3-3180