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

It can be shown in our material, that the most common species, Polemochartus liparae, consequently reared only from L. lucens pupae. The same holds true for Tetratichus légionárius, developing in L. lucens galls. Polemochartus aboletus has had only one known host, L. similis until today, too. The host species circle of Polemochartus melas and Stenomalina liparae has expanded. Thus, they do not seem to be selective on Lipara species as hosts, although they may have some preferences. The best example for this preference is the species Polemochartus melas, which, excepting a few case, develops in L. rufitarsis galls. The average percentage of galls occupied by Hymenopterans was the highest (25.2%) with this species. It represented only 4.5% of the total material. The high average could be considered as an artifact, because half of L. rufitarsis galls came from the same locality (Hidegség), where almost in 50% of the examined galls P. melas developed. This example is related to the uneven distribution of parasitoid species through time and space, as well. The bulk of the data in the literature supports our results, although there are adverse opinions, too. The reliability of our observations is strongly supported by the large material examined comprising nearly 4000 galls and by our skill in identifying the galls. Apparently in several cases L. pullitarsis is disfavoured by parasitoids among the Lipara species. The galls of this species made up almost 30% of the material, and only in 1.2% of it developed parasitoids. Three quarters of these parasitoids were Stenomalina liparae. The low level of infection might be attributed to the weak structure of the galls, which when compared to some more robust galls can desiccate much more easily, so the Hymenopterans might perish inside the gall. As it has been demonstrated above, different levels of specialization can be considered among the parasitoids developing in Lipara galls. Regarding the discussed parasitoid species we may conclude, that although their life history is attached to the Lipara galls, they are obligate members of the biocoenosis of the reed-belts, since their galls are present only on reed shoots. ASSOCIATION ASPECT The occurrence of more than one Hymenopteran species In the course of our observations, the galls reared mostly specimen/s of one Hymenopteran species. However, several times specimens of three or four species were found in the rearing pot. Species from the rearing pot of one year old L. lucens galls: Prosactogaster erdoesi + Platygaster sp. Torymus arundinis + Aprostocetus sp. 1. Torymus arundinis + Aprostocetus sp. 2. Torymus arundinis + Aprostocetus sp. 1. + Aprostocetus sp. 3. Species from the rearing pot of two year old L. lucens galls: Gasteruption kriechbaumeri + Hylaeus sp. Species from the rearing pot of L. pullitarsis galls: Polemochartus melas + Torymus arundinis + Aprostocetus sp. 1. Species from the rearing pot of L. similis galls: Prosactogaster erdoesi + Platygaster sp.