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.
A Nationally Notable (Nb) species (Falk, 1990).
Typically encountered in the vicinity of dead wood or on umbellifer flowers. Records seem to encompass a variety of habitats though in the southern part of its range it may be more of a woodland species than its congeners (Richards, 1980).
Probably univoltine; May to September.
Cells are stocked with flies such as larger syrphids (Lomholdt, 1975-76).
Nesting occurs in tree stumps, old trees, fence posts and other forms of dead wood.
Wild angelica, wild parsnip and hedge-parsley.
Hamm & Richards (1926) cite a foreign record of the chrysidid wasp Omalus auratus. Certain anthomyiid and sarcophagid flies could also be expected to parasitise this species.
1998