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

represented by single individuals, in the samples. As for the species with medium-level individual numbers, there are only two species, Medetera micacea and Aphanotrigonum bicolor NARTSHUK, 1964, which are not dependent directly on dung. As we have already stressed above, as regards dipterous adults present at a given moment on the surface of the individual cow pats, our method is not an estimation but a counting, on one hand. On the other, we are aware of the fact that even in this case we can only estimate the ratios in activities of the dipterous populations, and not those in their true abundance. Indeed, the relation of the activity to the abundance is different from species to species. Contrarily, we possess the numbers of individuals per species only. As we mentioned above, we belive, we have done our best to reduce the effects of diurnal and seasonal changes in detectable individual numbers of the dipterous populations. However, there were significant differences in the weather conditions of the three years. The year of 2003 was dry during the whole summer. The year 2004 was with higher than usual mean precipitation during the collection period that was also characteristic for the whole year of 2005. The number of the additional species compared to previous year is significant (Table 1 ). We are sure, there is no need of investigations of homogeneity to consider the high frequency changes in numbers as for the particular years. Consequently, if we combine them, we have to regard our procedure as combination of supplementary data rather than combination of repetitions. Therefore, the samples from the same day and those of the consecutive days are usable to estimate the same probability parameter. Combination of collections of more distant samples in time is probably not so. As regards the estimation to the real abundance of the populations, a combination of the results from different years should approximate to mean abundance. Despite the high sample sizes and number of samples taken, we found comparatively many additional species from one year to the other, and very irregular features of the species in the lowest frequency categories, etc. At least so, if we compare them to some sample series published on vertebrate communities or other less species rich animal assemblages. We think the reasons are not intricate. After all, we remained far below reaching the species pool. We are afraid, similar results have ever gained in studies of assemblages in less known habitats, on species rich assemblages, are to be regarded as a sign of the same inadequacy. As for their studies in the future, our results are recommended to be taken into consideration.