GENETIC-DIVERGENCE AND EVOLUTION OF POLYOMMATUS CORIDON GENNARGENTI (LEPIDOPTERA, LYCAENIDAE) IN SARDINIA

Electrophoretic analysis of 17 enzyme loci was carried out to assess t he genetic differentiation and isolation of the Sardinian Polyommatus coridon gennargenti from P. c. apennina of peninsular Italy and the re lated taxon P. caelestissimus from central Spain. P. c. gennargenti is represented by a small, strongly inbred population, restricted to the central mountains of Sardinia, and probably derived from mainland pop ulations as indicated by the reduction of genetic variation (P = 17.6 per cent, H = 0.024) with respect to the continental populations (P>52 per cent, H greater than or equal to 0.170). Absence of gene flow is indicated by the presence of alternative fixed alleles at the Aat, Gpi and Pgm loci and significant differences in allele frequencies at oth er loci, which distinguish the Sardinian population from P. c. apennin a and P. caelestissimus. The genetic differentiation of P. c. gennarge nti, as measured using Wright's F-ST values and Nei's genetic distance s, suggests the evolution of the Sardinian taxon along an independent lineage, facilitated by isolation and the strict dependence of the but terflies on specific biotopes, thus confirming its taxonomic status.