Nysson dimidiatus Jurine,1807
Synonyms
Nysson wesmaeli Lepeletier, 1845; Nysson distinguendus Chevrier, 1867; Nysson susterai Zavadil in Zavadil and Šnoflak, 1948; Nysson susterai Zavadil, 1951
Description and notes
A small red and black wasp which is a cleptoparasite of the similar looking Harpactus tumidus (Panzer), occurring in the same sparsely-vegetated sandy areas as its host.
Distribution
Recorded widely but sparingly across England and Wales as far north as Yorkshire and possibly Northumberland, though precise location(s) relating to the latter county (given by Richards (1980)) have not been found. Within this range, sites coincide with coastal areas and sandy districts. There are several old Channel Islands records and a few modem ones. Abroad, known from most of Europe; also Kazakhstan (Lomholdt, 1975-76).
Status (in Britain only)
Listed as Notable B by Falk (1991) (now known as Scarce (Nb)). Very scarce in most districts and considerably less frequent than its host, though both are small and easily overlooked. It has never been regarded as common in the past.
Habitat
Recorded from heathland, coastal dunes, coastal land slips, open areas in woodland, sandpits, embankments and occasionally gardens. Like its host, it favours sparsely-vegetated or short-cropped areas on dry sandy or clayey soils fully exposed to the sun. It is usually observed running rapidly over such ground or low vegetation during sunny weather, and can be captured by persistently sweeping such areas.
Flight period
Univoltine; June to September, with males emerging before females.
Nesting biology
A cleptoparasite of Harpactus tumidus, and usually obviously occurring alongside that species. The apparent absence of H. tumidus from some sites has led to suggestions that Lindenius albilabris (Fabricius) may be a secondary host.
Flowers visited
Umbellifers such as hogweed (Heracleum sphondylium) and wild carrot (Daucus carota).
Parasites
No information available.
Year profile last updated
Profile written: 2001
Proofed: March 2012