Straw belle moth (Aspitates gilvaria gilvaria)

KingdomAnimalia
PhylumArthropoda
ClassInsecta
OrderLepidoptera
FamilyGeometridae
GenusAspitates
SizeAdult forewing: 32-39 mm

Classified as Rare in the UK.

The hindwings of this moth are white with a faint diagonal grey streak and a dot on the upper surface. The forewings have a slightly graduated buff colour with a more noticeable brown diagonal streak pointing to the apex of each wing. The female is slightly more strongly marked than the male but this is not immediately obvious in the field.

The straw belle moth has been recorded in most European countries and its wider range extends across Asia to Mongolia. In the UK it is now restricted to small fragments of the North Downs of Surrey and Kent. It has declined in numbers severely, having been recorded formerly in Devon, Somerset, Gloucestershire, Hampshire, Sussex, Middlesex and Cheshire.

This is a species which inhabits chalk downland, especially that which is regularly grazed, on which its food plants can grow.

The straw belle moth is a resident of the UK. It normally flies at dusk but, if disturbed, will fly during the day. The moth emerges in July and is on the wing until August. The eggs are laid on a number of different chalk grassland plants including, thyme, cinquefoil and wild parsnip.

The caterpillars hatch in September and spend the winter as very small larvae, re-emerging in spring. They pupate in June before hatching in July.

This species has declined severely in recent decades, chiefly through loss of its habitat. This has been caused by a number of factors including road construction, housing and industrial development, and especially agricultural improvement to the calcareous grassland, which reduces the numbers of wildflower species. There has also been a decline in the traditional forms of grazing which have also led to habitat changes. There have been a number of cases of accidental and deliberate burning of the grasslands which support the straw belle moth.

As a result of the decline of the straw belle moth in the UK, it was introduced into English Nature's Species Recovery Programme. It is also listed as a UK Biodiversity Action Plan (UKBAP) priority species. In partnership with Butterfly Conservation, English Nature have drawn up a series of targets in an effort to save this species.

The remaining sites where the moth is found are all declared Sites of Special Scientific Importance (SSSIs) and the management agreements for these sites reflect the habitat requirements of the species. Two agri-environment schemes are available for landowners to encourage appropriate management of these sites and the aim is to achieve this by the year 2005. It is also hoped that by restoring other sites within the moth's former range, a re-introduction programme might be possible. Survey work, with the aim of identifying suitable locations and achieving the right type of land management, is currently underway.

  • For more information see Butterfly Conservation:
    http://www.butterfly-conservation.org/

    • Information supplied by English Nature.

    http://www.english-nature.org.uk