Neue Nachweise bi- und unisexueller 'Populationen' von Megabunus lesserti (Opiliones: Phalangiidae) in den Nordostalpen

New data on the sex ratio of 16 populations of the endemic harvestman Megabunus lesserti Schenkel, 1927 in the northeastern Alps confirm the previously assumed pattern of geographic parthenogenesis. Bisexuals inhabit a small area between the eastern margin of the Northern Calcareous Alps and the Ennstaler Alps, which was not covered by ice during the last (Würm) glaciations. Postglacially recolonized areas are occupied by parthenogenetic clones. Some all-female samples were found in close geographic proximity to bisexual populations. Apparently isolated occurrences at the western (Ammergau Alps) and southwestern (Carinthian) limits of the range proved to consist exclusively of females. A single male recorded in the Karwendel Mts. near Innsbruck is interpreted preferentially as a case of spanandry, being a fatherless "mistake" without any significant function.