The distribution of this species is significantly different from that published by Richards (1980), due to the separation in Britain of two species, T. nitidus and T. unicolor from the one taxon previously recognised as T. unicolor.
There is considerable confusion regarding the correct use of this name. As interpreted here this is the scarcer species of the two, apparently restricted to IOW and Dorset.
This species has a distribution apparently restricted to the south coast of the Isle of Wight and some places on the Dorset coast. It also occurs in the Channel Islands on Guernsey and Jersey. Overseas the species is widespread in the Palaearctic.
The species is not listed in Shirt (1987) or Falk (1991) as it was assumed then that all the black Tachysphex specimens from Britain were attributable to T. unicolor. Current knowledge indicates that this species warrants inclusion in future editions of the Red Data Book.
Mainly coastal areas, but occasionally heathland in Dorset.
Univoltine; probably May to August.
Grasshopper nymphs (Orthoptera: Acrididae).
Nests occur in the soil and are probably similar to those of T. nitidus.
These include field bindweed and spurges (G R Else, pers. comm.).
No information available.
1998