ELECTROPHORETIC COMPARISON OF DENDROCTONUS-PUNCTATUS LECONTE AND DENDROCTONUS-MICANS (KUGELANN) (COLEOPTERA, SCOLYTIDAE)

The taxonomic status of the American boreal spruce beetle, Dendroctonu s punctatus LeConte, and its Eurasian sibling species, the European sp ruce beetle, D. micans (Kugelann), has been in doubt. The genetic rela tionship of adult D. punctatus from Montana, USA, and of D. micans fro m Belgium was examined by isozyme electrophoresis. Average heterozygos ity and polymorphism was 0.075 and 37.5% for D. punctatus and 0.026 an d 6.25% for D. micans, much lower than reported in other Dendroctonus species and which may result from the high degree of inbreeding that i s characteristic of both species. Five of the 16 loci examined were fi xed, or nearly fixed, for different alleles in the two species. Geneti c identity between D. punctatus and D. micans was 0.693, lower than th at reported between two other, uncontested, host-isolated sibling spec ies, D. ponderosae Hopkins and D. jeffreyi Hopkins. Furthermore, the g enetic distance between D. punctatus and D. micans was 0.366, similar to another distinct pair of host-isolated sibling species, D. pseudots ugae Hopkins and D. simplex LeConte. These results support recent morp hological evidence in favor of retaining D. punctatus and D. micans as separate species.