2080       Euxoa obelisca [Denis & Schiffermüller 1775] SQUARE-SPOT DART     Notable/Nb

A local and decreasing species now confined to sea cliffs and rocky coasts in western and southern Britain and eastern Scotland, the larva feeding on various small herbaceous plants. In Dorset, the moth is common very locally and occupies two distinctly different biotypes. The first is the rocky coast terrain of Purbeck. Although equivalent geology and habitat exists on Portland, no Square-spot Darts have been recorded. The single record from West Bexington suggests dispersal from further west, moreover the two records from Charmouth hint at a colony there. The second is the muddy shore habitat bordering the western edge of Poole harbour, and, estuarine habitat in the mouths of the River Frome and the River Piddle immediately to the east of Wareham. This species closely resembles the White-line Dart₂₀₈₁, so care is needed in identifying the Square-spot Dart correctly. Diagnostics include: marginally broader-wings; ground colour akin to that of Heart and Dart; plainer in appearance. It is recommended that this species be included in habitat management plans for nature reserves that lie along the Purbeck coast and at Holton Heath (Natural England).

2081       Euxoa tritici (Linnaeus, 1761) WHITE-LINE DART

A coastal sandhill and heathland species in Britain, the larva feeding on various small herbaceous plants. In Dorset, the moth is locally common on coastal sandhills and on heathland, but is absent from clay and chalky soils. The White-line Dart is a highly variable species, and occasionally small dark forms approaching the closely related continental species Euxoa crypta are observed.

2082       Euxoa nigricans (Linnaeus, 1761) GARDEN DART

A lowland species most frequently found on the eastern half of Britain, the larva feeding on herbaceous plants and noted as a pest species on vegetables, cultivated plants, clovers (Trifolium spp.), plantain (Plantago spp.) and Umbelliferae. In Dorset, the moth is at low density and occurs in a variety of different habitats. It is found locally in the salt marshes of Poole Harbour, in suburban gardens in Dorchester, Weymouth, Swanage and Poole, and on rich soils within certain river systems such as the River Frome, River Piddle and the River Iwerne. The moth is strongly attracted to the flowers of ragwort. The individual illustrated is an aberrant example and was trapped near Wimborne by R  Stewart on 29 July 1948. Diagnostics include: bullet-shaped mark beneath orbicular stigmata seldom contains black scales; forewing length less than White-line Dart₂₀₈₁.

2083       Euxoa cursoria (Hufnagel, 1766) COAST DART     Notable/Nb

A very local species found on coastal sandhills in northern England, East Anglia, Wales and Scotland, the larva feeding nocturnally on sandhill plants, and hiding in the sand by day. A suspected immigrant was recorded at Dover in 1957. “This species must, at all times, have been extremely rare in the county, and it is very doubtful if it is now there. The records below I give full details of are reliable. I got the Wemouth specimens from A Druitt’s collection and dissected them, and agree the identity. Professor Varley allowed me to have the A Pickard-Cambridge specimens for examination and dissection; they were as A Pickard-Cambridge thought, true cursoria. The colouration is very curious. The general tone is cinnamon drab. The markings are nearly obsolete – one has a uniform and a traceable subterminal line. The other has the antemedial and post-medial line clearly marked but little else is traceable. The markings are a deeper tone of the general hue. Hope department numbers of slides are 389:1959 and 390:1959.” (W Parkinson Curtis ms). Dorset records are: Studland, along the shore to the south of the red rocks, after lunch on 22 July 1887 (Reverend E Bankes, C Digby), Weymouth, six bred from larvae (J Ridley), two at arbutus blossom (A Pickard-Cambridge), Pennsylvania, undercliff (Pickard-Cambridge, O Pickard Cambridge).

 2084       Agrotis cinerea [Denis & Schiffermüller 1775] LIGHT FEATHERED RUSTIC     Notable/Nb

 A local species restricted to southern Britain and found most frequently in south-east England, the larva feeding on wild thyme (Thymus polytrichus). In Dorset, the moth is common very locally in unimproved short-turf grassland habitat on chalky soil inland, along the Purbeck coast and on Portland. Colonies have declined since the Second World War due to the loss of unimproved short-turf calcareous grassland following changes in farming methods plus the crash in rabbit numbers from the 1950s due to myxomatosis and consequent reduction in close-cropping. It is recommended that this species be included in habitat management plans for unimproved grassland sites on chalky soil.

2085       Agrotis vestigialis (Hufnagel, 1766) ARCHER’S DART

A predominantly coastal species on sandhills in Britain, more local inland, the larva feeding nocturnally on grasses and herbaceous plants. The adult is strongly attracted to the flowers of ragwort, marram and heather. In Dorset, the moth is well established and common very locally on heathland, especially so on the Studland peninsular where dune habitat merges with heathland. The moth exhibits variability in its markings and colouration, and the silvery-grey ground colour with a distinct vinous tint contrasting strongly with the dark markings on the wing create a striking insect. The only record well away from acid soils is: Portland, at MV light on 20 August 1991 (M Cade).

2087       Agrotis segetum [Denis & Schiffermüller 1775] TURNIP

A widespread species throughout Britain, commonest in the south-east and scarcest in the north-west, the larva leads a subterranean existence feeding on the roots of a wide range of vegetable species and herbaceous plants. Larvae are often reported as serious pests abroad in roots of different vegetables. In Dorset, the moth is ubiquitous and common, and has been trapped in every month except January. The peak of the autumn brood is, on average, approximately five times larger than that of the summer brood. The national norm is for a partial second brood only. Undoubtedly, indigenous populations are reinforced by immigration, and it is noticeable that peak numbers of Turnip moths recorded from light traps operated on the coast coincide with immigration events, particularly during the autumn. The mini-peak in February on the phenology chart picks out the influx of this species during the remarkable winter immigration of 2004. The steady increase in numbers through the year is reminiscent of other common immigrant species, for example Dark Sword-grass₂₀₉₁ and Pearly Underwing₂₁₁₉.

2088       Agrotis clavis (Hufnagel, 1766) HEART AND CLUB

A species occurring throughout south-east England becoming progressively more scarce further north and west, the polyphagous larva at first eats the foliage of the host plant, then descends beneath the ground to eat the roots. The larvae are a serious pest of various crops in Europe. In Dorset, the moth is locally common among unimproved grassland along the coast and inland on both alkaline and on acid soils. It is rare on heathland. The national norm is for a single brood in June, but in Dorset a small partial second brood occurs during August and September, often following warmer than usual summers.  

2089       Agrotis exclamationis (Linnaeus, 1758) HEART AND DART

A species often associated with cultivated land and one of the most abundant moth species occurring in England and Wales, but becoming less frequent further north, the larva feeding on a wide range of plant species. In Dorset, the moth is ubiquitous and abundant. In favourable years trap totals are vast, for example, 19000 at Furzebrook in 1976 and 11000 at West Bexington in 1996. The national norm is for a single brood from mid-May to late July, but in Dorset the moth is bivoltine, and in ten of the past twenty-five years, potential third-brood individuals have been trapped during the second half of October. The period between the average theoretical brood peaks is roughly sixty days.

2090       Agrotis trux (Hübner, 1824) CRESCENT DART

A coastal species in southern England and Wales, the larva feeding on a herbaceous plant species. In Dorset, the moth is confined to sea-cliff habitat with no geological preference, where it is common very locally. The national norm is for a single brood in July and August, but the following light trap records suggest a partial second generation in some years during the autumn: West Bexington, on 24 September and on 16 October 2005 (R Eden), Portland, on 25 September 1961 (C de Worms) and on 17 October 1996 (M Cade), Durlston, on 12 November 1990, 12 November 1995, two on 16 November 1997 (P Davey), and on 19 October 2008 (Dr J Clarke).

Crescent Darts noted inland are few and are likely to refer to dispersed individuals from core coastal habitat. The following light trap records refer: Iwerne Minster, on 10 July 1955 (H Moore), Colehill, on 27 June 1964 (H Driver), Bere Regis, on 5 July 1996 (S Barrett).

2091       Agrotis ipsilon (Hufnagel, 1766) DARK SWORD-GRASS

A cosmopolitan, multivoltine species and a regular immigrant to Britain, most often seen in the south, the larva feeding nocturnally on or beneath the surface of the ground on herbaceous plants and vegetables. In Dorset, the moth is ubiquitous and has been trapped in every month except January, although numbers vary greatly from year to year depending on the size and northward extent of immigration from north Africa into Europe during the spring months. Spring immigrants have been noted in fifteen out of the past twenty years, however, numbers so early in the year tend to be small. By early July, second brood adults emerge, but further influxes from Europe augment resident populations. There is no evidence that the species overwinters in the county, and it is thought that all stages perish during the first frosts of winter; the status of the moth is therefore an immigrant and transitory resident.  

2092       Agrotis puta (Hübner, 1803) SHUTTLE-SHAPED DART

A widespread species in southern Britain, but absent from northern districts, the larva feeding on herbaceous plants. In Dorset, the moth is ubiquitous and common, occasionally abundant, and, historically: “sometimes, in the Poole district, the larvae are a rather serious pest, as they bite off the young growth of vegetables just below the surface of the ground.” (W Parkinson-Curtis ms). The moth is double-brooded in the county with the peak of the second brood, on average, twice as large as the peak of the first. The many records of adults at light traps in October and into November suggest a partial third brood in most years, a situation mirrored abroad. Years of abundance coincide with warm summers, the highest annual total of 3500 recorded from Furzebrook in 1976.

2093       Agrotis ripae (Hübner, 1823) SAND DART     Notable/Nb

A very local species restricted to the seaward side of coastal sandhills in England, Wales and eastern Scotland, the larva feeding nocturnally on sandhill plants, especially prickly saltwort (Salsola kali), sea rocket (Cakile maritima) and orache (Atriplex spp.), and hiding in the sand by day. In Dorset, the moth is frequent extremely locally on sand dune systems on the south-east coast. It was formerly abundant on Studland, and colonies were evidently established between Weymouth and Portland: Chesil Beach, thirteen in June 1890 (Reverend E Bankes et al), many different colour forms some almost white (N Richardson, 1896, Dorset Field Club, 17:160), Ferrybridge, at sugar on 10 July 1889 (Reverend E Bankes, N Richardson), Sandsfoot Castle, disturbed amongst the sand and gravel pits on 28 June 1886 (Reverend E Bankes, Reverend C Digby). The moth’s favoured host plants have declined dramatically due to human pressures. Prickly saltwort used to be locally plentiful on beaches between Charmouth and Highcliffe, but recent counts have revealed just fifty plants at Shell Bay and three more on the ‘unspoilt’ Furzey Island. Sea sandwort (Honckenya peploides) ranged all along the coast in the past, but it too has disappeared from most sandy beaches where people congregate, and now it is just an occasional, restricted to Burton Bradstock, north Portland, Poole Harbour and Christchurch Harbour. Sea rocket has survived at just a few sites along the Purbeck coast, in Poole Harbour and in Christchurch Harbour, but the plant has disappeared from many other beaches, again due to human pressures. The Sand Dart is evidently under threat from the decline of its unique and precarious sand/strand-line habitat. Conservation agencies should explicitly reference this species in the management plans that govern the protection of sand dune system flora and/or shingle flora at Chesil Beach, Studland, Brownsea Island and Hengistbury Head SSSIs.

The following light trap records refer to potential dispersed or immigrant examples (abroad it is found along the western and northern coasts of Iberia and France, thence eastward along the north European coast to Lithuania: Lyme Regis, on 29 June 1994 (B Henwood), West Bexington, on 5 July 2004 (R Eden), Portland, on 20 July 1995, 27 July 1995, 20 June 2000 (M Cade), Church Ope Cove, on 28 June 1986 (D Brown).