Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 4. (Budapest 1952)

Kovács, L.: The Eupithecia communities and the problems of their evolution in our swamps and reeds (Lepid.)

species were not found in the reeds ; these specimens had possibly wandered away from their breeding places. This reedy area does not seem to be suitable for the establishment and breeding of Eupithecia species. The collectings on the southwestern area of Lake Velence, concerning its reedy shores, had the same results.. Here also, few, only 4, Eupithecia species were caught : centaureata, graphata, subnotata, and pumilata ; the latter in two, the others in one specimen each. Graphata is a xerophilous species preferring steppe terrains, and so may have arived here from the insolated slopes of the hills, ranging north of the lake. The other species are generally distributed. According to these data, Eupithecia species do not seem to find their conditions in the reeds and so they are unable to create a characteristical community in it. All the species found hitherto in reedy territories occur also in their neighbourhood, and must have turned up there, in some cases at least, incidentally. There is no doubt that we shall know the Eupithecia species of our swamps in that case only if the course of their development can be traced. Though it is still very difficult, we may learn something about the phases of their development from the data at our command. The first to find their conditions of life were those of our Eupithecia species which prefer a higrous microclimate. Our postglacial climate was colder and more humid; birch swamps covered large areas on the Plains and of the flat regions of the eastern Transdanubium. These conditions were certainly agreeable to plumbeolata, valerianata, selinata, and absinthiata, which are found only in the swampy areas of the Plains, even to-day. In the alteration of the original situation two circumstances have played significant parts. One of them was the warming up of the climate, the second was the intrusion of man into the household of nature. Both had some effects in the change of the ancient-features of the Plains. Warmer climate made possible the establishing of new plant associations, and, dependent partly on this fact, of new animal species. This, of course, happened to the restriction of the older species which slowly drew back, and became isolated. Human interference hastened changes, confining the formerly very extensive swamps to mere strips to-day. As the conditions became more infavourable, the higrophilous Eupithecia species wandered away or perished, and could survive in such places only where the conditions did not reach pessimum. Such places, the remaining swampy spots, are their refuge now. The conditions of the environments are influential more or less to these spots, too ; so, though some of the later arrived species enter here, they are unable to increase significantly. The simultaneous prevalence of the above factors manifest themselves in the low dominancy numbers of the ancient species in Bátorliget and in the wet part of the woods of Vörs, as also in the small specimen numbers of such species which are generally distributed or even locally abundant. The biotop in which changes were less prevalent, received fewer of the newly arrived species. To these Bátorliget belongs, with its more ancient plant formations and colder microclimate. Bátorliget, according to S o ó and Zólyomi, preserves the most faithfully the postglacial features of the Plains. This is affirmed also by the respective data of Eupithecia, as there still exist all four hogrophilous species,, and also the number of species are~comparatively small. The erstwhile swampy areas of the wet woods of Vörs have greatly lost their characetrs to-day, owing to the influence of man. Those swamp fragments which remained there, are all interwoven also by other kinds of plant associations, their microlimate is not so palustrine,. and so, more Eupithecia species find their conditions to successful breeding. There are certain other factors prevailing in the formation of differences in the course of alterations, which are not in connexion with the forming of local