2428       Chrysodeixis chalcites (Esper 1789) GOLDEN TWIN-SPOT

A rare immigrant species that is resident in Africa and a transitory resident in southern Europe, the polyphagous larva feeding on various wild and cultivated herbaceous plants and vegetables. It has also been imported several times to the UK in the larval stage on tomatoes and chrysanthemums. In Dorset, the moth has been recorded eleven times at light traps and always along the coastal belt in airflows originating in the region of the western Mediterranean and Iberia. West Bexington, on 10 October 1995, 19 October 2005 (R Eden), Wyke Regis, on 26 August 2002 (D Foot), Portland, on 13 September 1987 (E Smith), on 4 and 14 September 1991 (M Cade, N Hall), Arne, on 29 September 1983 (B Skinner), Arne Wood, on 30 September 1983 (B Pickess), Harmans Cross, on 13 October 1990 (B Withers), Highcliffe, on 9 September 1985 and on 2 October 1990 (E Wild).

2429       Chrysodeixis acuta (Walker 1858) TUNBRIDGE WELLS GEM

A rare immigrant species seen on twenty occasions in Britain, the first in Kent in 1870 and then not again until 1955. The moth is resident in the tropics and the sub-tropics, the larva feeding on various wild and cultivated herbaceous plants and vegetables, including tomato and soybean. In Dorset, six moths have been seen, all at light traps: Sherborne, on 25 September 1967 (C Gibson), West Bexington, on 26 October 1995, 13 October 2005 (R Eden), Durlston, two on 26 October 1995 (P Davey). In each case, the source of origin is likely to have been the west coast of Africa south of 30ºN; at 4000 plus kilometres, this surely constitutes one of the furthest journeys undertaken by any moth species seen in the county. This species resembles the Golden Twin-spot₂₄₂₈. Diagnostics include: a bronze-coloured sheen on the forewing, not a golden sheen; a more rectangular wing reminiscent of Silver Y₂₄₄₁.

2430       Ctenoplusia limbirena (Guenée 1852) SCAR BANK GEM

A rare immigrant species seen on ten occasions in Britain, resident in Africa, and a transitory resident in southern Iberia, the polyphagous larva feeding on various wild and cultivated herbaceous plants. In Dorset, the moth has been seen on six occasions at light traps, the first of these (see photo) was the first British record, and the species acquired the name ‘Scar Bank’ after the place where it was caught: West Bexington, on 10 October 2008 (R Eden), Scar Bank, on 13 September 1947 (A Russell), Portland, on 29 July 1997, 24 August 2007 (M Cade), Durlston, on 17 September 1992 (via Durlston Country Park). The airflows on most occasions have tended to originate over western Iberia and the Atlantic coast of North Africa, although there was negligible opportunity for immigration from the south for up to three weeks prior to the record date in the case of the 2007 example. This species resembles Silver Y₂₄₄₁ superficially, but the ‘V’ part of the ‘Y’ is more like a ‘U’; it more closely resembles Ni₂₄₃₂. Diagnostics include: a violet hue across the forewing; a pale patch on the central edge of the forewing.

2432       Trichoplusia ni (Hübner 1803) NI

A scarce immigrant species, resident in the tropics and sub-tropics and a transitory resident to southern Europe, recorded mainly from southern counties of England and Wales, the polyphagous larva feeding on a wide range of plants. In the sub-tropics it is probably continuously brooded, and immigrants to the Mediterranean region in the spring spawn further broods that increase in size and expand northwards through the year. In Dorset, the moth visits the county irregularly and usually as singletons. Two generations are suggested by the data, with the peak of the second seven times larger, on average than that of the first. In June 1996, the notable influx of immigrant species from north Africa and the western Mediterranean discussed in the account of the Small Mottled Willow₂₃₈₅, produced a handful of Ni moths. A further wave of immigrants occurred during the second week of August, but small numbers were also trapped between late July and early September, regardless of weather type, suggesting a resident status for some in that year. There is a single record of larvae being found in the wild in Dorset, by Mrs N Richardson on rock samphire (Crithmum maritimum) on Portland; adults emerged on 6 and 10 September 1894, respectively. The great winter immigration of 2004 included this species: Cogden Beach, on 13 February 2004 (M Parsons, M Forster), Weymouth, on 12 February 2004 (Dr P Sterling), Portland, three on 11 February 2004, 12 February 2004 (M Cade), Durlston, on 12 February 2004 (S Nash).

2433       Thysanoplusia orichalcea (Fabricius 1775) SLENDER BURNISHED BRASS

A rare immigrant species that has been seen on less than fifty occasions in Britain, and resident in the sub-tropics and the tropics, and a transitory resident across the Mediterranean region, the polyphagous larva feeding on various wild and cultivated herbaceous plants and vegetables, and a pest species on potato (Solanum tuberosum) and soybean. It has also been imported several times to the UK in the larval stage on chrysanthemums. In Dorset, the moth has been recorded at light on five occasions: Sherborne, in October 1969 (C Gibson), Portland, on 17 October 2007 (M Cade), Winterborne Whitechurch, on outside porch on 23 June 2006 (I Cuff), Studland, on 8 October 1969 (S Coxey), Highcliffe, on 21 and 27 August 1983 (E Wild). The sources for all but one of the above are likely to have been the central and western Mediterranean, however, in the case of the 2006 example, the only opportunity for immigration from this region was eleven days previously.

2434       Diachrysia chrysitis (Linnaeus 1758) BURNISHED BRASS

A widespread species in Britain, the larva feeding on nettle (Urtica dioica) and dead-nettle (Lamium spp.), and occasionally on various other herbaceous plants. In Dorset, the moth is widespread and frequent, but at low density in open, unimproved grassland on all soil types, but rises to common in areas where improved farmland provides nitrogen-rich soils where nettle plants flourish. This is therefore one of the very few moth species to benefit from changes in agricultural practices in recent years. The moth is bivoltine and the peak of the first brood is on average, twice as large as the peak of the second.

                Diachrysia stenochrysis (Warren 1913)

This species and Diachrisia chrysitis₂₄₃₄ are apparently clearly distinct (both morphologically and ecologically) in Siberia and the Far East. However, the situation is more complicated in Europe, since the two do not appear to have any specific habitat requirements and both are quite variable. Both species are maintained in European checklists and therefore this species is added here until it is proven that these are all forms of Diachrysia chrysitis in Europe. The primary visual difference between the two in Asia is that the solid, unbroken central brown band of Diachrysia chrysitis is broken in Diachrysia stenochrysis.

2435       Diachrysia chryson (Esper 1789) SCARCE BURNISHED BRASS     Notable/Na

A rare species in Britain and confined to river habitat in Hampshire and Berkshire, plus coastal localities in south-west Wales, the larva feeding on hemp-agrimony (Eupatorium cannabinum). There are old records from two of Dorset’s river systems, the River Piddle and Caundle Brook, the last record about a hundred years ago. It is unlikely that this handsome species survives in the county as its preferred herb-rich chalk-stream gallery habitat has all but been replaced by intensive agriculture usually to the very edge of water courses: Charmouth, (B Morris per Dale), Glanvilles Wootton, (Dale), Caundle’s Holt, (Dale), Puddletown, at light on 1 August 1907 (A Morgan), Hyde House, in July 1889 (J Dunne Cook).

2436       Macdunnoughia confusa (Stephens 1850) DEWICK'S PLUSIA

A relatively recent immigrant species, the first seen in Essex in 1951, and at least one seen in most years this century. The species was originally resident in eastern Europe and Asia and has spread west and north from the 1920s; it is now resident over much of mainland Europe and Scandinavia, the polyphagous larva feeding on various herbaceous plants including dead nettle sp. (Lamium sp.), nettle (Urtica dioica), chamomiles (Chamaemelum nobile and Anthemis spp.) and mayweeds (Matricaria spp. and Tripleurospermum spp.), wormwood (Artemisia absinthium), although no larvae have yet been found in Britain. In Dorset, the moth has been seen at light traps on nineteen occasions: West Bexington, on 20 October 2001, 17 October 2005, 15 September 2008 (R Eden), Wyke Regis, on 22 September 1988 (P Baker), Weymouth, on 12 June 2006 (Dr P Sterling), Portland, on 19 and 20 October 2001, 28 June 2003, 26 July 2008, 12 September 2008 (M Cade), Preston, on 1 August 2004 (R Lambert), Puddletown, on 3 October 2001, 16 September 2006, 10 October 2006 (H Wood Homer), Winterborne Stickland, on 12 September 2000 (L de Whalley), Winspit, 22 July 2008 (P Davey), Gaunts Common, on 27 August 1992 (P Davey), Swanage, on 30 September 2008 (Reverend E Pratt), Durlston, on 18 October 2008 (M Deans et al). The region of central and western France appears to have sourced the majority of the moths seen across the county.

2437       Polychrysia moneta (Fabricius 1787) GOLDEN PLUSIA

A local species in Britain, first recorded in 1890 in Kent, the larva feeding on garden Delphinium and monk’s-hood (Aconitum Spp.). The first Dorset records were one taken at light at Tarrant Rushton in 1893, another on 18 June in the same year at Mudeford. The moth is very thinly spread in the county, with most records from gardens stocked with Delphinium. “The moth can be a garden nuisance by eating the tips of the shoots whence flowerbuds spring.” (W Parkinson Curtis). The following examples are suspected immigrants, and indeed the one in 1947 may have been from a continental second-brood: West Bexington, on 3 July 2006 (R Eden), Scar Bank, at light on 18 September 1947 (A Russell), Swanage, at MV on 26 June 2003 (R Cox).

2439       Plusia festucae (Linnaeus 1758) GOLD SPOT

A widespread wetland species in Britain, the larva feeding on sedges (Carex spp.), yellow iris (Iris pseudacorus) and water plantain (Alisma plantago-aquatica). In Dorset, the moth is local and at low density colonising fen, river, stream, ditch and lake habitat wherever reasonable quantities of its foodplants may be found. It has a tendency to wander, and has been trapped on dry soils well away from core habitat. The national norm is for a single brood in the north of Britain in July and August, and a double brood in the south in June and July and again in August and September.  A univoltine and a bivoltine cycle is suspected, with the dominant single brood from late-July until late-August, and a double brood apparent in June and from early September to early October.                                         

The exceptional heatwave in the first half of August 2003 brought with it many local wetland moths to non-wetland localities. Species included Small Rufous₂₃₇₉, Twin-spotted Wainscot₂₃₇₀, Brown-veined Wainscot₂₃₇₁, Webb’s Wainscot₂₃₇₃ and Bulrush Wainscot₂₃₆₉. Chief amongst these was the Gold-spot, and immigration from continental Europe may account for many of the following: Bridport, on 5 August (D Wedd), Walditch, on 11 August (M Parsons), West Bexington, on 2, 4, 6 and 7 August (R Eden), Dorchester, two on 5 August (J Down), Portland, on 3, 5, 7, two on 8 and 10 August (M Cade), Preston, on 5 August (M Forster), on 7 August (R Lambert), Puddletown, two on 11, 12 and 14 August (H Wood Homer), Motcombe, on 5 August (P Butter), Gillingham, on 6 August (G Hopkins), Shaggs, on 4 and 12 August (Butterfly Conservation), Wool, two on 3, seven on 5, two on 7 and two on 13 August (D Cooper), Trigon, on 4, 6 and 7 August (C Manley), Winterborne Stickland, on 7 and  two on 9 August (L de Whalley), Slepe Farm, two on 4, four on 5, two on 6, five on 7, 14 August (D Cooper), Swanage, on 7 August (R Cox), 10 August (D Leadbetter), Durlston, on 7 August (J McGill), Hengistbury Head, on 4 and 6 August (M Jeffes).

2440       Plusia putnami (Grote 1873) LEMPKE'S GOLD SPOT

A local marshland and occasional upland species restricted to East Anglia, northern England and southern Scotland, with isolated records elsewhere, the larva feeding on marshland grasses and plants. There is one record from Dorset: Bryanstone, on 17 August 1935 (D Hervey coll.)

2441       Autographa gamma (Linnaeus 1758) SILVER Y

A regular and often abundant immigrant to southern Britain, less so further north, the polyphagous larva feeding on a wide range of herbaceous plants and vegetables. The moth is active by day and by night. In Dorset, the moth occurs everywhere and has been trapped in every month, 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. Resident broods tend to become established from April onwards before dying out with the onset of winter frosts, however, the arrival of immigrants at any time of the year tends to blot out any underlying resident brood pattern. The following (mainly) light trap records are those where five hundred or more Silver Y moths have been observed on a single date: Scar Bank, two thousand on 8 June 1946, fantastic swarms on 4 August 1946 (A Russell), West Bexington, nine hundred on 4 August 1996, one thousand on 5 August 1996, two thousand five hundred on 13 August 1996, one thousand five hundred on 15 August 1996 (R Eden), Southwell, five hundred on 6 August 2003 (Dr J Clarke), Portland, fifteen hundred on 12 August 2003 (M Cade), Bulbarrow Hill, five hundred by day on 16 June 1996 (P Davey), Gaunts Common, five hundred on 3 September 1991, one thousand on 8 August 1996 (P Davey), Studland Heath, five hundred by day on 27 August 2003 (PAD), Durlston, five hundred by day on 25 June 2003 (P Davey), six hundred plus on 7 August 2003 (J McGill).

2442       Autographa pulchrina (Haworth 1809) BEAUTIFUL GOLDEN Y

A widespread species, and common in montane regions in northern Britain, the larva feeding on various herbaceous plants including nettle (Urtica dioica), dead-nettle (Lamium spp.), hedge woundwort (Stachys sylvatica) and wood-avens (Geum urbanum). In Dorset, the moth is widespread but at low density, being most frequent in open deciduous woodland. The national norm is for a single brood in June and July, however, in warm summers, there is a partial second brood from mid-August to mid-September.

2443       Autographa jota (Linnaeus 1758) PLAIN GOLDEN Y

A widespread species in England, Wales and southern Scotland, more local further north, the larva feeding on various herbaceous plants. In Dorset, the moth prefers open situations and is frequent in unimproved grassland on neutral or chalky soils; it is virtually absent from sandy soils, and at low density elsewhere including woodland. This species is similar to Beautiful Golden Y₂₄₄₂. Diagnostics include: a reddish-brown ground colour, not violet-brown; square panel of gold contrasts markedly with surrounding paler ground colour.

2444       Autographa bractea (Denis & Schiffermüller 1775) GOLD SPANGLE

 species of hill country, widespread in Wales, northern England and Scotland, the larva feeding on a wide variety of herbaceous plants, including nettle (Urtica dioica), dead-nettle (Lamium spp.) and bilberry (Vaccinium myrtillus). There are two records from Dorset. The first example is a suspected immigrant transported on south-easterly winds from central Europe: Bournemouth, flew into lighted bedroom window on 19 July 1933 (S Scarsdale Brown). Prior to 1940, the species had a distribution that was very much restricted to alpine regions. Since that time, it has become more widespread across northern Europe. The second example occurred in a northerly airflow originating over Scandinavia but also passing across northern England: Coldharbour, on 15 August 2006 (B Withers). A record month’s total of four Great Brocade₂₁₃₇ occurred across the county during August 2006; one of these was recorded at the same location (Coldharbour) by B Withers on 19 August.

2449       Abrostola triplasia (Linnaeus 1758) DARK SPECTACLE

A thinly spread species in England and Wales, local in Scotland, the larva feeding on nettle (Urtica dioica) and hop (Humulus lupulus). In Dorset, the moth until fairly recently was rare and at low density in river valleys where hop festoons hedgerows, notably on the Stour, the Moors River, and the Piddle, but has increased quite dramatically of late. Originally there was little evidence to support a resident status for the species, but currently, the moth seems to be regularly recorded from a few sites, notably those close to river valleys. This increasing trend seems mostly due to immigration, with in excess of fifty moths trapped in 2001 and 2003 appearing amidst notable immigrations from mainland Europe. The national norm is for a single-brood in June and July, but the Dorset records indicate a double brood pattern, with the peak of the mid-summer brood one-third higher on average, than that of the early autumn peak. Coupled with this are the suspected immigrant peaks in late May, late July and early October, reflecting a trivoltine cycle abroad.

Given the capacity of this species to migrate, it is worth mentioning that two similar species occur abroad, so it may be worth checking dark ‘Spectacles’ examples, particularly at times of immigration. These two are similar to triplasia, although both are marginally greyer. Also, the inner-most semi-circlular black line separating the ochreous region from the remaining dark ground colour of the forewing on triplasia, forms an acute angle (less than thirty degrees) as it approaches the basal edge of the forewing. The other two species have this line forming an angle of forty-five degrees or more with the basal edge of the forewing, so that it appears more of a shallow curve than a full semi-circle along its whole length. The two Continental species are: Abristola asclepiades which has a southern, central and eastern distribution in Europe including Iberia, Germany and southern Scandinavia, and Abristola agnorista which occurs in southern Europe and is essentially a Mediterranean species.

2450       Abrostola tripartita (Hufnagel 1766) SPECTACLE

A widespread species in Britain, the larva feeding on nettle (Urtica dioica). In Dorset, the moth is widespread and frequent, but common in areas where improved farmland provides nitrogen-rich soils where nettle plants flourish. The national norm is for a single brood in the north of Britain from late June until mid-July, and a double brood in the south from late May to June and again in August and September. However in Dorset, a univoltine cycle plus a bivoltine cycle is suspected, with a single brood from early June to mid-July, and a double brood from late April to mid-June, and again from August into September. This species resembles the Dark Spectacle₂₄₄₉. Diagnostics include: basal and tournal areas whitish-grey not ochreous-brown. If this wasn’t enough, confusion has also centred on the Spectacle being assigned the latin name Abrostola triplasia in the past, the present name of the Dark Spectacle₂₄₄₉.