Adult Scarce Blackneck moths are similar in appearance to the blackneck moth (Lygephila pastinum), but have a deeper black collar behind the head and four dark marks along the front edge of the fore-wings (3). The wings are pale grey to brown (3). The slender caterpillar reaches 3.6 cm in length, and is pale brown in colour with a darker mottled stripe along the back (4).
Eggs are laid singly on the leaves of the foodplant in summer, where they overwinter and hatch the following spring. The caterpillars feed at night until June and pupate on the soil surface; the pupa is covered by a silk cocoon(4). The adults emerge in July and August (4) and fly at dusk (3).
In the UK, this species is currently restricted to 6-7 isolated coastal sites in north Cornwall, north Devon and Somerset (5). These populations are vulnerable to local extinction (2). Elsewhere, the species has a wide distribution in Europe from Scandinavia to Crete in the south (2).
Inhabits coastal cliffs and rocky areas (1) where occasional slippages occur (2). The disturbance caused by these slippages results in good habitat for the caterpillars' foodplant, Wood vetch Vicia sylvatica(2).
The main threats to this species are the stabilisation of the coastal cliffs on which it lives and collection of caterpillars at well-known sites (2). The growth of rank vegetation due to natural succession can cause the loss of populations of the Scarce Blackneck, as can severe landslips (2).
The Species Action Plan for the Scarce Blackneck produced under the UK Biodiversity Action Plan (UK BAP) aims to maintain the current known populations (2). This species is the subject of a regular monitoring scheme on one of the sites, which is a Devon Wildlife Trust reserve (2).
The UK Biodiversity Action Plan for this species is available at UK BAP.
A sheath of silk, which is spun around the pupae of some insects (a pupa is a stage in an insect's development, when huge changes occur that reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis).
The progressive sequence of changes in vegetation types and animal life within a community that, if allowed to continue, result in the formation of a 'climax community' (the last stage in a succession where the vegetation reaches equilibrium with the environment).
Stage in an insect's development when huge changes occur, which reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis.
The process of forming a pupa, the stage in an insect's development, when huge changes occur that reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis.
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