Crabro aurilabris (HERRICH-SCHÄFFER,1841); Crabro chipsani (MATSUMURA,1912); Crabro contiguous (CRESSON,1865); Crabro lineatotarsis (MATSUMURA,1911); Crabro longipalpis (VERHÖFF,1892); Crabro nigrifrons (CRESSON,1865); Crabro planifrons (THOMSON,1870); Crabro septentrionalis (PACKARD,1866)
A large Ectemnius resembling the common E. cavifrons but scarce in most areas. Formerly known under the names nigrifrons (Cresson, 1865) and planifrons (Thomson, 1870).
Present in England and Wales as far north as the Scarborough area of North-east Yorkshire and the Grange-over-Sands area of Westmorland. A strangely patchy distribution is shown, with clusters of records in parts of Hampshire, Surrey, Kent and Yorkshire, but elsewhere it is exceedingly scarce, even in well-recorded districts such as Dorset, Sussex, East Anglia and parts of the Midlands. It appears to have markedly increased its presence in northern England over the last few decades, and there is little evidence of serious decline anywhere. Recently recorded from the Channel Islands. Richards (1980) lists County Antrim in Ireland (but details of this record are lacking). Very extensive overseas distribution, incorporating the Holarctic and Neotropical regions.