Range & Status
Recorded in Britain only from the rocky north coasts of Cornwall, Devon and Somerset (Spalding, 2003). Local in western Europe.
In Cornwall, recorded from cliffs either side of Bude. The only recent records are from Welcombe and Marsland nature reserve and near Crackington Haven, apart from a single on The Lizard in 1985 (West, 1986).
Habitat & Ecology
The larvae feed mainly on Wood Vetch Vicia sylvatica , which is rare in Cornwall and confined to the north coast north of the Dizzard. This plant survives on freshly exposed soil, relying on landslides on the loose slate cliffs. Other vetches may be used in the wild (Heath & Emmet, 1983) and in fact larvae were found feeding on Tufted Vetch Vicia cracca at the well known site of Hartland Point in Devon (Henwood, Spalding & McCormick, 2004) - but the distribution of the Scarce Blackneck in Cornwall closely follows the distribution of Wood Vetch. The exception is the 1985 Lizard record (West, 1986), which might have been a migrant Scarce Blackneck or possibly one of the other European Lygephila species; the specimen was not retained. The adults fly in July and August.
Collecting the larvae may be a threat at the well-known Devon locality and could pose a threat in Cornwall. However, the foodplant grows on undercliff scree which is inaccessible to most people.
One of the main Cornish sites is on a nature reserve; another is on National Trust land.