O. Merkl szerk.: Folia Entomologica Hungarica 69. (Budapest, 2008)

sources. In case of sepsid flies, the proportion of species occurring on both types of dung is reduced to about half of the above value. Finally, no muscid species occurred on both types of dung in our samples. There are two types of biases potentially influencing my results. Firstly, low sample size can cause an underestimation of the proportion of shared species. Secondly, some species may occur on a particular type of dung without necessarily depositing eggs in it, thus causing an overestimation of shared species. Consequently, these biases may potentially act in opposite directions; however, the amount of their influence is not yet understood. Further studies are needed for a better understanding of the potential conservation value of the dung fly communities associated to large herbivores. Firstly, we need species descriptions and taxonomic reviews to quantify more accurately the similarities among different fly communities associated to different herbivores. Secondly, specificity of a dipteran to a particular dung type should be characterised by the development of the larvae within the dung, rather than by pure occurrence of imagines in the pats. Finally, elephant-dominated versus cattle-dominated grazing fields could be considered as two extremes of a single habitat continuum, and a bettersubstantiated project would be extended along this continuum. I simply hope that the preliminary results presented above can signify the importance of the insect communities living in association with the large-bodied 'megafauna'. Acknowledgements - The fieldwork was supported by the Hungarian Scientific Research Fund (OTKA K 60593). I am grateful to MIHÁLY FÖLDVÁRI for help in the field, to LAJOS RÓZSA for advice, and JUDIT GALAMBOS, ZSUZSA PETROVICS and ESZTER ZAHORÁNSZKY-VIDA for mounting and labelling specimens. REFERENCES CLAYTON, D. H. & PRICE, R. D. 1999: Taxonomy of New World Columbicola (Phthiraptera: Philopteridae) from the Columbiformes (Aves), with descriptions of five new species. - Annals of the Entomological Society of America 92: 675-685.