Untersuchungen der Dipterenfauna in natur- und industrienahen Rasenbiotopen Thüringens (DDR) mittels Bodenfallen (Diptera Brachycera)

Abstract

11 778 specimens of Diptera were caught in pitfall traps in two nearly natural grasslands and a grassland polluted by immissions of a phosphate-factory in Thuringia/GDR. The activity density (number of individuals caught in pitfall traps) of the families Chloropidae, Phoridae and Sphaeroceridae clearly dominate in each of the biotopes. In the surroundings of the phosphate-factory a high IJUmber of the halobiontic Pelomyiella mallochi (Tethinidae) and other halophilic species were caught. The investigations include tests of diversity, of RENKONEN, of time constance (persistence) and representan~e, i.e. the percentage of the total abundance of a species, in the number of the 6 catena units, 1 selecte~ in the industrial area. The zoophagous adults only represent 9.7%-17.8% of total specimens, but a higher number of zoophagous species were caught (14. 7% 26.6 %). Some remarkable species of brachypterous flies have been identified. The saisonality of dominant species caught by the pitfall trapping method exhibits a distinct relationship to the saisonality of these species caught by sweep net method in the Leutra valley near lena/Thuringia.