Four-spotted moth (Tyta luctuosa)
|Size||Wingspan: 2.5- 2.9 cm (1)|
Classified as Vulnerable in Great Britain (2).
The common name of the Four-spotted moth refers to the white spots on the fore- and hindwings, which stand out in stark contrast to the dark brown background colour (3). The edges of the wings have white flecks (4). The caterpillar, which may reach 3.5 cm in length, is pale reddish-ochre in colour and has two dark bands on the back and a white band along both sides (5).
Since the 1930s, this species has undergone a severe decline. It was once quite common and widespread throughout England, south of Norfolk and Somerset. In recent years however, it has been found in just 11 counties and is now recorded regularly from just three (6). Elsewhere it is known throughout Europe (with the exception of Ireland and Norway), and reaches Siberia and Morocco (2).
Inhabits grasslands, and is usually found on south-facing slopes with patches of bare ground. It requires a source of the larval foodplant field bindweed (Convolvulus arvensis) (2).
The four-spotted moth is mainly single-brooded(5), but often produces a second brood within its more southerly colonies (6). Adults fly in sunshine and at night from mid-May to mid- August, but the precise time of emergence depends on the climate (1). Eggs are deposited singly on the stems or flower buds of the foodplant during June. Caterpillars can be found at night on the foodplant in July and August, and occasionally later in the year. The overwintering stage is the pupa(1), which develops in September under the ground protected by a tough cocoon(5).
Much suitable habitat has been lost to development or changes in farming practices. On remaining habitat, unsuitable management practices have excluded the vulnerable Four-spotted moth (2).
This moth is a UK Biodiversity Action Plan (UK BAP) priority species, and as such a Species Action Plan has been produced to guide conservation action. This plan aims to maintain and enhance all current populations and return self-sustaining populations to 10 sites within the historic range by the year 2010 (2). The latter proposal may be met through a series of reintroductions (2). Other measures which have been suggested to help the species include extending the area of suitable habitat available at current sites and attempting to link up fragmented patches of habitat (2).
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 Sean Clancy.
- Cocoon: 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).
- Larval: of the stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Pupae: 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.
- 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
- Personal observation from images.
- South, R. (1961) Moths of the British Isles. Frederick Warne and Co. Ltd, London.
- Carter, D.J. and Hargreaves, B. (1986) A field guide to caterpillars of butterflies and moths. William Collins and Sons, London.
- Clancy, S (2003). Pers. comm.