MORPHOLOGICAL AND GENETIC-VARIATION IN THE SPECKLED WOOD BUTTERFLY (PARARGE AEGERIA L.) AMONG DIFFERENTLY FRAGMENTED LANDSCAPES

We compared morphological and genetic variation between populations of the speckled wood butterfly (Parage aegeria L.) from four landscapes differing in degree of fragmentation: a continuous woodland, a set of woodland fragments, another, more isolated set of woodlots and a highl y fragmented area with very small woodland fragments and hedgerows sca ttered in an intensively used agricultural landscape. Male butterflies were collected, weighed and their wing features (size and colour) mea sured by means of an image analysis system. We used Polyacrylamide Gel Electrophoresis (PAGE) to investigate generic variation. The dearest morphological differences were found between the large, continuous woo dland and the three other areas. Males of this woodland had a paler ba sal and distal forewing colour and larger yellow patches on the dorsal side of the forewing. Since these features are relevant to thermoregu lation and anti-predation, this result suggests differences with respe ct to microclimate and predation between the study areas. Relative tho rax size also increased with degree of fragmentation. Since the thorax contains the flight muscles, this result may relate to differences in patterns of mobility or different costs for the same mobility pattern . The genetic diversity of the butterflies of the large, continuous wo odland was significantly higher than in the other study areas. There w ere also indications for genetic differentiation. Hence, this study ma y point at adaptive morphological variation in the speckled wood butte rfly among differently fragmented landscapes.