Chalk carpet moth (Scotopteryx bipunctaria cretata)
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Insecta |
| Order | Lepidoptera |
| Family | Geometridae |
| Genus | Scotopteryx (1) |
| Size | Wingspan: 32- 38 mm (1) |
Classified as Nationally Scarce in Great Britain (2).
Adult Chalk Carpet moths are pale grey in colour with grey-brown markings, and have a darker central band with two black dots, one above the other in the pale central area of the band (3). The hindwings are grey, and lack the brown markings (3) (4). The caterpillar reaches up to 2.5 cm in length and is yellowish-grey in colour with dark lines along both the back and sides. It has a brown head with a yellowish tint (5).
Largely confined to chalk and limestone areas, and is most common in southern England as a result. From the Midlands northwards and in Wales it has a more local distribution as far as Yorkshire and formerly County Durham (6). Outside of the UK, this moth is known throughout central and southern Europe and reaches Asia Minor (3).
Inhabits unimproved calcareous grasslands, with a preference for sites with exposed rock and bare patches that are grazed short (2). Old quarries are often favoured (6).
Adults of this single-brooded moth fly at night (2) in July and August (1). Eggs are laid in August, and hatch in September. The caterpillars are active at night (5) between September and June feeding on legumes such as bird's foot trefoil (Lotus corniculatus) and various clovers (1). The caterpillars overwinter when they are still fairly small (5); they start feeding again the next spring and reach their maximum size in June (5). The pupal stage develops in the ground (2) at the base of the foodplant (5).
This species is thought to have declined, factors responsible include the loss of natural grassland to agriculture and housing, or to scrub following the abandonment of sheep-grazing. This has caused fragmentation of habitat (6).
A Species Action Plan has been produced for the Chalk Carpet moth under the UK Biodiversity Action Plan (UK BAP); this plan aims to maintain the current range of the species. Conservation work has been carried out on a number of occupied sites, which are nature reserves, Sites of Special Scientific Interest (SSSIs) or consist of land brought under agri-environment schemes(2).
The species action plan for the Chalk Carpet is available on-line from:
http://www.ukbap.org.uk/
Further reading on moths:
Leverton, R. (2001) Enjoying Moths. Poyser, London.
Skinner, B. (1984) Moths of the British Isles. Penguin Books, Harmondsworth
Information authenticated by Roy Leverton.
- Agri-environment schemes: these schemes allow the government to compensate farmers for using methods that benefit the environment. The two main initiatives in the UK are the Countryside Stewardship Scheme and Environmentally Sensitive Areas. Since October 2000 these have formed part of the England Rural Development Programme (EDRP), administered by DEFRA, the Department of Environment Food and Rural Affairs. See http://www.defra.gov.uk/erdp/erdphome.htm for more on these initiatives.
- Calcareous: containing free calcium carbonate, chalky.
- Pupal stage: 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.
- Single-brooded: (Also known as ‘univoltine’). Insect life cycle that takes 12 months to be complete, and involves a single generation. The egg, larva, pupa or adult over winters as a dormant stage.
- Skinner, B. (1984) Moths of the British Isles. Penguin Books, Harmondsworth.
- UK BAP Species Action Plan (December 2001): http://www.ukbap.org.uk
- South, R. (1961) Moths of the British Isles. Frederick Warne and Co. Ltd, London.
- Pers. observation from images.
- Carter, D.J. and Hargreaves, B. (1986) A field guide to caterpillars of butterflies and moths. William Collins and Sons, London.
- Leverton, R. (2002) Pers. comm.