Metapopulation pollination in the deceptive orchid Anacamptis pyramidalis

Pollen dispersal between local plant populations within a range of 6 km in a geographically defined metapopulation of the lepidopteran-pollinated deceptive orchid Anacamptis pyramidalis was studied on the island Öland in the Baltic Sea. Local A. pyramidalis populations were examined for pollinators, flowering individuals, and fruit set. Population sizes of pollen vector species were estimated using a mark–release–recapture technique. As pollen vectors, the burnet moth Zygaena minos and the butterfly Aporia crataegi dominated. 205 out of 745 marked lepidopterans were pollinarium carriers. The proportion carriers of the total was considerably higher in Z. minos (50.3%), than in A. crataegi (21.5%) and nymphalidae (8.2%). Furthermore, Z. minos moved much shorter distances than A. crataegi did, while no difference in potential pollen dispersal distances were found between males and females. The number of individual vectors recaptured in another local population of A. pyramidalis was low: A. crataegi (8) and Z. minos (1). The ratio of pollinaria transferred to another local A. pyramidalis population compared to pollinaria remaining within the same local population was 1:41. This study highlights that pollen dispersal distances vary between pollen vector species.