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

regional units are compared. These annual means in the above order of sequence are: 24, 26, 9, 6, 6, and 3. M. vitellina produces in general 3 generations south of Hungary. According to local and the annual weather conditions, however, the number of broods varies in our country; it may be 1, 2 or even 3. The specimens of the second generation are most frequently encountered, whereas the first one cannot be observed everywhere in every year, indeed, of 35 traps 10 had not yielded it as yet. Specimens deriving from the third generation were caught by 10 traps hitherto, one each during three years or Two years, respectively, the others only once. The period separating the annual broods is generally one month (Table 1 and Map 3). With respect to investigating the migrating character of the species, it is a most important circumstance that the first brood appears constantly only locally, and there too not contiguously everywhere (Maps 1, 3). As is to be seen, traps which had contiguously ór approximately contiguously captured it, operate in the southern part of the Great Plains. The further away to the west or the north from the south of the Plains we get, the less traps will be found which had already captured the first generation of vitellina, and even if they captured it, this happened on gradually decreasing occasions with the increasing distance. This circumstance is prevalent even if the numerical ratios of the first and second generations are shown per regional unit. The ratio in the Plains between the Danube and the Tisza is 7:8, in the Southwestern Transdanubia 2:3, in the Trans-Tisza Region 7:16, in the Northeastern Transdanubia 1:3. The other data have no decisive importance owing to the low individual numbers (5:9 and 2:9, respectively). The number of individuals of the first brood is so high in the Great Plains that in the flight diagram the peak, falling on the turn of May and June, describes the swarming just as markedly as in the second. In other regions, the peak is very obscure or completely lacking in the diagrams of the first generation. In Hungary, the first brood flies from the beginning of May to the beginning of June, the second from the middle of July till the middle of October, and the third in November, but only given suitable weather conditions. These flight periods agree in essence with those observed for the species in South Europe and Asia Minor. Evaluation of the data M. vitellina indubitably inhabits the southern parts of the Great Plains in Hungary. This statement can be substantiated by the following arguments: The first brood is observable there from year to year or in the great majority of years. Accordingly, the rate of individual numbers vies with those of the second generation. The migrating lepidoptera, appearing in Hungary, usually show no first brood here, or if so, only occasionally and in low individual numbers (KOVÁCS, 1959). Furthermore, the flight diagram, plotted with recourse to the quantitative data deriving from the southern part of the country, displays the characteristic; features of the diagrams of our aboriginal species. And going by analogous cases, this part of the country is suitable for the continuous breeding of thermophilous species (e.g. Eucrostes indigenata VILL.; KOVÁCS, 1953, 1956). One might also add that the early exemplars of the migrating species invariably display damages in the scales and cilia, owing to the prolonged flight, whereas the majority of the vitellina specimens, originating from the southern part of the Great Plains, are whole, be they captured by individual collectings or by the light traps. There is no dispute over the fact that merely a restricted part of the area