P. principalis (Stach, 1945)

– Arrhopalites binoculatus f. principalis Linnaniemi, 1912: 273

– Arrhopalites principalis Stach, 1945: 37

AK MacLean et al. 1978, cf.; Fjellberg 1984a

BC Cannings 2010

AB Parsons & Parkinson 1986, 1986a

Remarks: There appear to be serious discrepancies between European and American taxonomists in understanding of this species. It was absent in the first edition by Christiansen & Bellinger (1981) but was added later (1998) after Fjellberg (1984a, p. 207) note that “the Colorado specimens [identified by him as A. principalis] do not differ from specimens from Norway, Spitsbergen, northeast Siberia (Chaun Bay), Alaska (several records), and Washington (Mt. Rainier)”. He also added that “although principalis has not been reported from North America until now, some samples may have been confused with the Nearctic benitus Folsom ”. We believe that

some older records of binoculatus from northern parts of Alaska and Canada may belong to P. principalis and not P. pygmaeus (see remarks on the latter species). General distribution: probably Holarctic.