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
territory. According to the known data, the centers of its occurrence lie in the Budapest hills, the Mts. Dunazúg, the Mts. Börzsöny, and the SW feet of Mts. Cserhát. This may also be explained by the fact that the best exploited regions of the country lie around the Capital, yet it is also true that it occurs in really big numbers in some places around Budapest. In this connection, we have to raise the question oj the most favourable habitats of britomartis. Our own observations testify that this species dislikes completely open spaces and strongly insolated points. We have always collected it in the glades of woods or fields planted with shrubs and saplings, and once in a clearing. Its preference to fresh forest clearings is supported by the data of N. Natt án of Kaposvár. According to him, britomartis appears quite suddenly in clearings one or two years old, increases in numbers gradually for a while, and when the trees grow to such heights that they shadow the ground, it vanishes again to reappear in other, fresh clearings. The inclination of the places where we have collected it at lower altitudes is usually Eastern-Northeastern, therefore of a moderate insolation even when the sun stands high. At higher altitudes, on the Bükk plateau, it occurs in larger numbers even in flat areas, yet mainly on northernly inclined places also here. Some of the collecting places are completely dry, disproving its alleged preference to moisture : we have to conclude rather that it avoids strong sunlight. We have not yet found its caterpillars even by methodical search, and only one specimen had successfully hatched from a caterpillar brought home with other larvae indistinctively. This caterpillar was collected in the forenoon. Trustworthy data on the flight of britomartis cover the period of 26 May to 23 July. It is sooner on the wing in warm years, and disappears generally sooner, too, not extending to July. Flight begins later in cold summers, stretching to later dates. So, for instance, in the cold and rainy summer of 1944, fresh females could be found around Budapest yet in the first days of July. At higher altitudes, approximately above 500 meters the date-lines shift to later times. The phenological data of the Kaposvár populations fall to surprisingly late dates as compared with the ones of the Central Mountains (20. June —23. July) i then those of the Mts. Sátor (25. June —18. July), too. Zoogeographical Problems. M. britomartis was collected, related to the enormous area where it had hitherto been found, in relatively few places. This holds good not only to its Eastern but also to its occurrence in Europe. The meagre number of collecting localities is indubitably in connection with its difficult separation from the two related species. This is supported by the fact that, even before the problem of its occurrence in Hungary was solved, it had already been caught in about 30 localities. We feel sure that it will yet be found in the course of further exploitations in many other places in this country, but still more so in other regions where this question was paid less attention to. With regard to its general distribution, a striking picture takes form even from the data of the present days. If the collecting localities found in literature and in this paper were to be put on a map, it would become apparent at once that the majority could be found almost on the same latitudes in Europe as in Asia. The area of occurrence of the Asian populations lie between latitudes 47 and 53, whilst all trust worthy European data refer to_points between latitudes 46 and 53. We know
