The queens emerge from the middle of May, workers are in flight from June to August and males in August and September.
Nomenclature: Løken (1973) used the name B. arcticus Kirby for this species because she considered B. arcticus (Quenzel) to be a nomen oblitum. However, this is not supported by the present Code for a publication of this date (ICZN, 1999: Article 23.12), although it does allow B. arcticus (Quenzel) to be suppressed by use of the Plenary Power. See the comments on B. hyperboreus.
It is suggested in the comments on B. hyperboreus that, in the interests of stability (ICZN, 1999: Article 23), an application be made to ICZN to use its Plenary Power (ICZN, 1999: Article 78) to suppress B. arcticus (Quenzel), the unused senior synonym of B. hyperboreus. This would free B. arcticus Kirby from junior primary homonymy with B. arcticus (Quenzel) (ICZN, 1999: Article 57), so that B. arcticus Kirby would become the valid name for this species. However, although the name B. arcticus Kirby has been in use for this species (e.g. Løken, 1973; Sakagami, 1976; Svensson & Lundberg, 1977; Reinig, 1981), the more frequently used name has been B. polaris (e.g. Milliron & Oliver, 1966; Milliron, 1973a; K. W. Richards, 1973; Hurd, 1979; Pekkarinen, 1979; Pekkarinen et al., 1981; Rasmont, 1983; Pekkarinen & Teräs, 1993). In the interests of stability, the application to ICZN for B. hyperboreus might be extended to suppress B. arcticus Kirby, in order to conserve the current usage of B. polaris as the valid name (in prep.).