Primary and 'stepping-stone' habitats in history — the example of peat-bog Lepidoptera in the Palatine (S.W. Germany) : The current state of our research into the present and past distribution of peat-bog macro- and microlepidoptera (and some other insects), and their potential migration routes from primary to secondary habitats in the Palatine (S.W. Germany) is summarized. A comprehensive study of the topic is in preparation and will be published at a later date. Entomologists are invited to contribute and exchange information on the mentioned species (see list, pp. 20-21), especially their ecology and distribution. Data from northern Vosges, France, would be particularly welcome.

Most of the habitats in which tryphophilous or tryphobiont insects live in the Palatine today could develop due to the activities of man, especially the building of dams to form ponds for various purposes (e.g. fishery, milling, iron processing, wood transport). Peat-bog vegetation was able to colonise the edges of these ponds, but only in areas with low water nutrient content and acid conditions. Because the ponds are, or have been, very close to each other and to the peat-bog areas of the 'Westricher Moorniederung' (see Fig. 1), insects could migrate step by step from the primary habitats to the secondary areas around the ponds, thus reaching areas which are more than 50 km from the area of origin. In addition to the chain of ponds functioning as 'stepping-stones', open valleys have been important in enabling migration along rivers and streams under conditions microclimatically and structurally suitable for the respective species.

The potential migration routes, derived from the distance and direction in which the respective species have been found, and also from geological, geographical and historical data, is given in Fig. 5. Most probably further areas in the northern Vosges have also been reached by some of the species.

Boloria aquilonaris Stichel, is taken as an example that could be more or less representative of all the species mentioned (Fig. 6). Due to the destruction of the primary peat-bog areas in the Westricher Moorniederung and the strong decline in the number of ponds in the area, most of the populations of the species studied have now disappeared. Most probably almost none will survive the near or distant future because of the combination of natural effects (succession) and indirect human influences (e.g. air pollution and thus nutrient deposition ; possibly also climatic changes as a result of man's activities).