Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 5. (Budapest 1954)

Issekutz, L. ; Kovács, L.: Melitaea britomartis Assmann, with special regard to its occurrence in Hungary

only of four points more southern than these : two in Italy, one in Southern Moldova (Tecuci), between latitudes 45—46, and the Bulgarian one between latitudes 42—43. If we take into consideration therefore that britomartis inhabits in Europe the preponderantly Middle-European climate zone, with only isolated populations in the South (these also in the vicinity of Pleistocene glacial centres : the Alps, and Mts. Balcan), the question of the whereabouts of its glacial réfugies will spontaneously emerge. It is believed of our high mountain animals that they found shelter during the period of glaciation in regions of a milder climate in the South, returning gradually to the mountainous districts with the coming of the warmer period. If this were applied as an analogy to britomartis, it had then to draw back even more southwards to have had found a refugy conforming to its present distribution. This supposition, at least in the light of our recent data, rests on a shaky ground, as this species has never been found even on high mountains in expressedly southern areas. The problem could be explained away otherwise, too, by the recently very fashionable assumption that, after the lapse of the glacial periods, it had immigrated to Europe from Eastern Asia, from the ancient Angara continent. We may believe, from our part, in justifiable cases, that certain species really did immigrate from the east to populate formerly glaciated territories and their environments, but we do not hold this explanation absolutely necessary in every case. Not especially so in the case of britomartis. One glance on a map showing the annual isotherms suffices to recognize the fact that certain britomartis populations live in territories north to the zero grade isotherm in Eastern Asia, wherefore they can, endure relatively low temperatures. The annual main temperature was not so low during the glaciation of Hungary. A. Kéz published in his paper in 1938 the results of his investigation in this regard. He came to the conclusion, after having carefully deliberated on the most diverse factors, that the annual main temperature during the glacial periods in our country oscillated between grades 0- +3. If this were so, we can safely suppose that species able to live in colder climatal zones could survive also in Hungary. On the ground of above circumstances, we relegate britomartis among these species. On our opinion, the strongerly isolated southern slopes of the Hungarian Central Mountains offered suitable shelter to numerous lepidoptera during the cold glacial climate. We have already mentioned that britomartis avoids areas of strong insolation, so, for instance, the southern slopes. In this fact we see an adaptation to changed climatal circumstances. This adaptation happened partly through the change of the biotop : the departure from the southern slopes (active adaptation), partly from becoming gradually adapted to higher yet not extremely warm climates on the new colder biotops (passive adaptation). The data given above, in the systematical part, indicate, however, that the britomartis populations, living now in Hungary did not spread from a single refugy after the glaciation. The britomartis population of Kaposvár displays considerable diversities both in its external characters and in the peculiarities of the male genital armature, — being also territorially isolated among and from the other Hungarian britomartis races. Furthermore, the Kaposvár specimens differ from the ones of the Transsylvanián Border Mountains, separated by the extensive area of the Great Plains. From the fact that britomartis has never been foundveven in the marshy areas of the Great Plains, one may conclude that britomartis is not indigenous there, since the same swamps are the