The majority of these taxa have very similar mitochondrial COI and Cytb gene sequences (Nyman et al. 2007, Leppänen et al. 2014), and many species share the same CO1 barcode BIN in BOLD: acutifoliae, arcticornis, brevicornis, collactanea, glabrifrons, hastatavora, myrsiniticola, myrtilloidica, nivalis, reticulatae, saliciscinereae, and samolad. Nevertheless, the more detailed analyses of Leppänen et al. (2014) revealed clearly different haplotype and allele frequencies in mtDNA COI and/or nuclear ITS2 gene among population samples collected from different willow host species in northern Fennoscandia. Furthermore, in most cases, some morphological differences associated with numerous biological characters leave little doubt that the majority are distinct species. In BOLD, only the barcodes of kriechbaumeri, pedunculi and viminalis are widely separated from each other, and also from the large, shared BIN occupied by the taxa listed above.