Numbers
50 species listed at
Natural History Museum (Palearctic and Nearctic). Approximately 21 are Nearctic.
Habitat
Mountain-meadow, forest, grassland, semi-desert, and tropical montane forest.
Life Cycle
Nests underground or on the surface.
Remarks
In many places in California, especially inland and to the south, B. caliginosus can be eliminated from consideration based on range as it has never been recorded there and should not occur (wrong habitat, climate, etc). Please consult Thorp et al. for details about their ranges.
To the north, especially at the coast, both species (B. caliginosus and B. vosnesenkii) could occur and ID is very difficult at best from images alone. . . difficult to separate even with specimens. (Comment by John Ascher).