Apis saltuum PANZER 1801; Psithyrus vestalis var. leucoproctus LEPELETIER 1832; Bombus varians SEIDL 1838;
Keys and general biology are found in Sladen (1912), Free & Butler (1959), Alford (1975) and Prŷs-Jones & Corbet (1991). Until recently this species was known as Psithyrus barbutellus, but Psithyrus has now been reduced to a sub-genus within Bombus. It bears a close resemblance to its host, Bombus hortorum, but has an almost circular face, most unlike the very elongated one of B. hortorum.
This species is distributed widely throughout most of the area covered by this Atlas, but is rarely common. It is widespread in Europe; middle and northern latitudes of Asia, and eastwards to Mongolia (Løken 1973).