S. Mahunka szerk.: Folia Entomologica Hungarica 43/1. (Budapest, 1982)

Fig. 1. Changes in dominance of populations with different ecological valence in 1977-1980. (I-TV.: as in Table 4) species, both spending the winter in the form of eggs. 17.5 p.c. of the species spend the winter in larval stage and 14.3 p.c. as imagos. These values are on the sand hills: 40.4, 25.0, 17.3 and 17.3 p.c. 40 p.c. of the species living in the wind furrows are dry-grassland specific, 26.2 p.c. are xerophilous, 15.4 p.c. are indifferent and 18.4 p.c. are non-characteristic. These values are on the sand hills: 51.8, 27.7, 14.3 and 6.1 p.c. Both the number and population proportions of the dry-grassland specific species living on the sand hills have dominant role, but in the wind furrows the fewer species of xerophilous and indifferent groups have bigger populations. The changes of the structure of leafhopper community follow the successional changes of plant associations. It is apparent In the qualitative regrouping of the species with different ecological valence, after changes in the quantitative rates of certain populations. REFERENCES ANDRZEJEWSKA, L. (1971): Productivity investigations of two types of meadows in the Vistula valley VI. Production and population density of leafhopper (Homoptera - Auchenorrhyncha) communities. - Ekol.pol., 19: 151-172. ANDRZEJEWSKA, L. (1974): Analysis of a sheep pasture" ecosystem in the Pieniny Mountains (The Carpathians) V. Herbivores and their effect on plant production. - Ecol.pol.

, 22:527-534. BODROGKÖZY, Gy. and FARKAS, Gyöngyi (1981): Correlations between vegetation and hydroecology in the sandy grasslands of Kiskunság National Park. - Acta Biol. Szeged.. 27(1-4): 33-53. DLABOLA, J. (1954): KriSi - Homoptera.' - In: Fauna 6sR, 1-339. Praha. GALLÉ, L. - GYORFFY, Gy, - HORNUNG, E.H. (1981): Number and biomass of arthropods living in a sandy soil grassland. - In preparation.