To re-evaluate the taxonomic status of Cheilosia canicularis (Panzer, 1801), C. himantopus (Panzer, 1798) and C. orthotricha Vujić & Claussen, 1994, variation in the mitochondrial DNA (mtDNA) sequence of the cytochrome c oxidase subunit I (COI) gene and 18 nuclear allozyme genes were surveyed in allopatric and sympatric populations from Serbia and Montenegro. Genetic relationships among five populations of these species from the Fruška Gora (Serbia), Kopaonik (Serbia) and Durmitor (Montenegro) mountains were analyzed. Seven allozyme loci (Aat, Aco, Fum, Idh-1, Idh-2, Mdh-2 and Sdh) were diagnostic for delineating C. orthotricha from the other two species, while only a low, but consistent, genetic differentiation was observed between C. canicularis and C. himantopus. Differentiating all three species was possible based solely on the species-specific alleles at the Est-? locus. Sequence comparisons of 738 bp of the COI gene from eleven specimens was consistent with the variability in nuclear allozymes. Sequence data revealed variation in 5% of the nucleotide sites among C. orthotricha and the C. canicularis/C. himantopus pair, while less variation (0.68%) was observed within the pair C. canicularis/C. himantopus. However, the presence of one diagnostic allozyme locus and five consistently variable nucleotide sites in sympatric populations of C. canicularis and C. himantopus (Durmitor, Montenegro) suggest that these two species have separate gene pools.
Variation of 15 nuclear allozyme genes and a 708 bp fragment of DNA sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene were surveyed in a population of a hoverfly species, Merodon desuturinus Vujić, Šimić & Radenković, 1995 (Diptera, Syrphidae), endemic to the Balkan Peninsula. Based on phylogeography and taxonomy, Merodon desuturinus is of special interest from a biogeographical and conservation perspective. Characterization and determination of genetic relationships between M. desuturinus and taxa of the M. aureus, M. avidus, and M. ruficornis groups on the Balkan Peninsula were estimated based on molecular markers (allozymes and COI sequences). We observed that the mean number of alleles per allozyme locus was 1.1, frequency of polymorphic loci 0.067, and heterozygotes were absent. Our results showed an extremely low genetic variability in the M. desuturinus population sampled. We suggest that this taxon calls for a conservation management plan, as it is likely a vulnerable and threatened taxon, an endemic, spatially divided species and represents a unique genetic unit on the Balkan Peninsula.