Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 63. (Budapest 1971)

Kovács, L.: Data to the knowledge of Hungarian Macrolepidoptera VI. Data with respect to migrating and spreading species

Map 3. Mythimna vitellina HBX. — Occurence of first generation of vitellina lies within our borders. The required conditions, outlined above, of its constant breeding exist fully only to 46°30' northwards between the Danube and the Tisza, and to 46°50' northwards in the Trans-Tisza Region. The conditions characterizing the picture of distribution of our home species gradually loosen northwards and westwards, thus these parts of the country already belong to the periphery of the area. This peripheral area can be divided largely into two zones in Hungary. In the first zone the species is still regularly observable and the first brood appears also more frequently, occasionally even in consecutive years. Manifestly, the species may temporarily breed even for some years in this zone, but is unable to settle definitely. The western borders of the first zone largely coincide with those of the regular occurrence of vitellina, extending, however, northwards to the foothills of the mountains between the Danube and the Tisza and to about the hight of Debrecen beyond the Tisza. In the farther zone the localities of occurrence become rarer, individual numbers decrease to the minimum, and the appearance of specimens representing the first brood is an exceptional phenomenon. Since some specimens advance also beyond our borders (HRUBY, 1964; STERZL, 1967), this outer zone of the peripheral area obviously extends northwards and westwards to Hungary. By the enclosed maps (1 and 2), inferences can be drawn not only on the starting points of the migrations of vitellina, but also on their main directions. Since, counted from the southern parts of the Great Plains, individual numbers decrease in all directions, it seems hardly contestable that in the Carpathian Basin the starting point of the migrations is the Southern Plains, including also their part lying south of our borders. The routes of migrations radiate from this area in all directions. The species occurs quite exceptionally along the rivers Drava and Mura, so immigration from this direction can hardly be assumed.