O. Merkl szerk.: Folia Entomologica Hungarica 68. (Budapest, 2007)

dipterous larvae; their number is not significant and they are not food specialists. In this sense this multispecies assemblage has no biological i.e. functional structure. Basic models of species abundance structures like the truncated lognormal model of species abundance distribution and similar models are based on the independence of individual species frequencies, that is, they are so-called neutral models (IZSÁK Sc PAPP 2008). From an ecological point of view our project is not a study of the fly assemblages of cow pats, but rather an abundance survey of Diptera populations captured on cow pats in a definite state of succession, on a definite small area in a definite moment, demonstrated by a very high number of samples. Cow pats form a rapidly changing environment with a conspicuously rapid succession of insect assemblages (PAPP 1971 ). In the moment of falling down to ground, beetles and flies appear on them. As for Diptera, first visitors are species of Haematobia LE PELETIER et SERVILLE, 1928 and Haematobosca BEZZI, 1907, Sepsis cynipsea (LINNAEUS, 1758), Sepsis thoracica (ROBINEAU-DESVOIDY, 1830), Musca autumnalis DE GEER, l776,Musca larvipara PORTSCHINSKY, 1910, Adia cinerella (FALLÉN, 1825). In addition, in the first half of an hour Hydrotaea tuberculata RONDANI, 1866 and other Hydrotaea ROBINEAU-DESVOIDY, 1830 may lay their larvae there. Adults of Neomyia cornicina (FABRICIUS, 1781) and those of the dominant species, Coproica lugubris (HALIDAY, 1836), may be found on the freshest dung. Later adults of Coproica lugubris became most numerous, indeed. Some hours old cow pats are visited by other species of Sepsis FALLÉN, 1810, the two species of Saltella ROBINEAU-DESVOIDY, 1830 inhabiting Hungary, Ravinia pernix (HARRIS, 1780), etc. One to two days old cow pats are visited also by the adults of the two European Lotobia LlOY, 1864 spp., several species of Ischiolepta LlOY, 1864, Chaetopodella scutellaris (HALIDAY, 1836) and numerous species of Muscidae, which come to find proper place for their eggs. In that stage of succession we can find also adults of Hybotidae species (Crossopalpus humilis (FREY, 1913), C. minimus (MEIGEN, 1838), C. setiger (LOEW, 1859), Drapetis flavipes MACQUART, 1834, possibly also other species), which hunt there on minute flies, mites and other small arthropods. They lay eggs on/into in several days old dung only. Several days old cow pats are still attractive for species of Chironomidae (Pseudosmittia GOETHGEBUER, 1932), Sphaeroceridae (Opalimosina ROHÁCEK, 1983 spp., Philocoprella RICHARDS, 1929 spp.), etc. Larvae of the latter species are feeding on bacteria and microfungi, rather than on the original matter of the dung.