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

(populations of the marshes nearby but also sylvicolous species). Although the species in the last group are not members of the coprophagous or pasture assemblages, sheep-runs in the Hungarian Great Plain serve as important stepping stones or buffer zones for numerous insect populations in those mosaic landscapes. As we have stressed in the introduction, the method used does not seem proper to be used in true quantitative analysis of the species richness of the ecosystems. Our method does not give results equally proportional in every animal group as for the species present and found. It seems rather probable that the number of the autochthonous populations is underestimated (e.g., as regards the homopterans on sandy soil vegetation, or on saline grasslands in Hungary (cf. Györffy and Kincsek 1986, 1988). The movements of phytophagous insect populations were demonstrated between grassland areas and adjacent areas also in Hungary Diagram 1. Sheep-runs as experienced by a (Györffy and Szönyi 1989). We have lesser dung fly found representatives of forest populations, though. As we pointed out in a recent paper (Papp 1995) small or minute flies, which use the pasture vegetation as take-off grounds, blown by the wind randomly to places close to droppings and oriented by smells from a short distance. These small flies do not fly away from the droppings when disturbed but just crawl or jump off and hide among the grass roots, etc. keeping olfactory contact. This is summarized in Diagram 1. This kind of studies cannot be regarded as ecological in the narrower sense: since the environmental parameters were not measured (the temperature of air and soil, etc. are the components of the milieu but they are not studied as acting factors here). Consequently, the differences found within a sample series or between two sample series, must not (and cannot) be interpreted as tolerance answers of the insect communities. The differences found are simply the reflection of the possible variance of abundances (at the present level of investigations they are probabilistic). Of course, this is valid also for the former papers of this kind (e.g., Papp 1992, 1993). Otherwise, a quantitative analysis of the sample series are given in a subsequent paper. We thought all these circumstances must be stressed although the short grass "puszta" which are evenly grazed (or even overgrazed) by sheep looks very homogenous from place to place at Kunszentmiklós. However, the seemingly isomorphic habitat was found heterogenic for some of those terricolous species, like Metopina sp., on the other hand. Unfortunately, there is no possibility to reconstruct the ecological factors behind this finding, since we do not know even the exact place of the pan-traps where they were on the "puszta"; this is another lesson for plans in similar but higher level investigations. emergence from soil i crawling up the vegetation <i blown up and away by wind I a random landing I Is there a good dropping nearby; is the fly able to smell it? YES NO I Find the dropping i Eat, mate and lay eggs disturbance I Jump off and hide among grass roots