Chequered skipper (Carterocephalus palaemon)
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Insecta |
| Order | Lepidoptera |
| Family | Hesperiidae |
| Genus | Carterocephalus (1) |
| Size | Wingspan: 2 - 3 cm (1) |
Extinct in England (2). A UK Biodiversity Action Plan Priority Species, and protected under Schedule 5 of the Wildlife and Countryside Act, 1981, with respect to sale only (3). Classified as Vulnerable in Europe (4).
As the name suggests, this small, fast-flying, chocolate-brown butterfly has a chequered patterning on both the hind- and forewings. Although the sexes are similar in appearance, females are somewhat larger than males (1). The caterpillar grows to 2.3 centimetres in length; before it undergoes hibernation it is green with darker green and white lines, but after emerging it becomes brownish white, with pinkish-brown and white lines (5).
In Britain, this butterfly is currently found only in a small part of western Scotland. It was formerly common in England in the East Midlands, with a few records from as far south as Dartmoor. It became extinct in England in 1976 following a prolonged decline that began in the early part of the twentieth century, but accelerated after the 1950s. Elsewhere the species is widely distributed through Europe and Asia, reaching Japan. It also occurs in North America reaching north to Alaska. It is currently in decline in many parts of Europe and is threatened in Japan (2).
In Scotland, the chequered skipper breeds in open grassland. It prefers the edges of woodlands, and most breeding sites tend to occur at the bottom of slopes and at the edges of rivers and lochs (2). In England it inhabited rides and clearings in woodlands, as well as fens and scrubby grasslands (2). It requires the presence of the foodplants of the caterpillar; in Scotland the main foodplant is purple moorgrass (Molinia caerulea), but in England false brome (Brachypodium sylvaticum) seemed to have been preferred (2).
A single generation is produced each year; the adult flight period occurs between the third week of May to the end of June (2). Eggs are laid singly on a blade of grass, and hatch after ten days or so (5). The caterpillar creates a tube by spinning the edges of the grass-blade together; it emerges from this shelter in order to feed above it (5). Below the shelter it makes notches in the leaf, which may help to retain nutrients and prevent defensive chemicals from entering the region above the shelter (2). Towards the end of September the caterpillar creates another, larger shelter consisting of a number of leaves, in which it hibernates, emerging the following spring (5). It does not feed at this time, but pupates amongst vegetation (2). The adults emerge towards the end of May (5).
The extinction of this butterfly in England is believed to have been the result of changes in woodland management, in particular the decline of coppicing (2). In addition, some sites were cleared in order to plant conifers (2). At present, unsuitable grazing levels (3), browsing by deer (2) and loss of open areas in woodlands are remaining threats (3).
The chequered skipper is a priority species under the UK Biodiversity Action Plan. A Species Action Plan has therefore been produced in order to guide conservation action. Butterfly Conservation has also produced an action plan for this butterfly; both action plans are available on-line (see links below). Trade in this species is illegal under the Wildlife and Countryside Act of 1981. An experimental re-introduction programme was started in 1990, with releases of adults at a restored site in Lincolnshire in 1997-9. Breeding has been recorded, but it is not yet known if these trials will prove successful in the long-term (2). Despite these promising steps, conservation action must be concentrated on the remaining natural populations in Scotland, which are still very vulnerable to changes in woodland management (2).
For more information on the chequered skipper see:
- Asher, J., Warren, M., Fox, R., Harding, P., Jeffcoate, G. and Jeffcoate, S. (2001) The Millennium Atlas of Butterflies in Britain and Ireland. Oxford University Press, Oxford
- The Butterfly Conservation website:
www.butterfly-conservation.org
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: arkive@wildscreen.org.uk
- Coppicing: traditional form of woodland management in which trees are cut close to the base of the trunk. Re-growth occurs in the form of many thin poles. Woodlands are cut in this way on rotation, producing a mosaic of different stages of re-growth.
- Hibernation: a winter survival strategy characteristic of some mammals in which an animal’s metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer. In insects, the correct term for hibernation is ‘diapause’, a temporary pause in development and growth. Any stage of the lifecycle (eggs, larvae, pupae or adults) may enter diapause, which is typically associated with winter.
- Pupates: 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.
- Re-introduction: an attempt to establish a native species back into an area where it previously occurred.
- Rides: often the footpaths and access tracks which run through and divide blocks of trees in woodland. Many rides contain a mixture of rich flora and structure, and provide different habitat conditions for a range of wildlife.
- Carter, D. (1992) Butterflies and Moths. Dorling Kindersley, London.
- Asher, J., Warren, M., Fox, R., Harding, P., Jeffcoate, G. and Jeffcoate, S. (2001) The Millennium Atlas of Butterflies in Britain and Ireland. Oxford University Press, Oxford.
-
UK Biodiversity Action Plan: Species Action Plan (October, 2002)
http://www.ukbap.org.uk/UKPlans.aspx?ID=192 -
Ravenscroft, N.O.M. and Warren, M.S. (1996) Butterfly Conservation Species Action Plan for the Chequered Skipper (Carterocephalus palaemon). Butterfly Conservation, Wareham. Available at:
http://www.butterfly-conservation.org/uploads/cs_action_plan.pdf - Carter, D. and Hargreaves, B. (1986) A Field Guide to Caterpillars of Butterflies and Moths in Britain and Europe. William Collins & Sons Ltd, London.