2399       Pyrrhia umbra (Hufnagel 1766) BORDERED SALLOW

A species found mainly in south-east Britain, more coastal elsewhere but largely absent from Scotland, the larva feeding on restharrow (Ononis spp.). In Dorset, the moth is at low density along the coastal belt. The records listed below refer to occasional singletons that turn up inland. These may either be wanderers from the coast or originate from colonies on what remains of unimproved grassland on chalky or clay soils inland where common restharrow (Ononis repens) is still found. The national norm is for a single brood in June and July, but the moth has occasionally been noted as early as the first week of May and as late as the last week of August in Dorset. This suggests a bivoltine cycle in favourable years, as happens on the Continent.

2400       Helicoverpa armigera (Hübner 1808) SCARCE BORDERED STRAW

A regular immigrant species to southern Britain, most often recorded in southern coastal counties, and becoming progressively scarcer further north, the polyphagous larva feeding on wide variety of plants in the tropics and sub-tropics and in Britain occasionally found on imported fruits and cultivated flowers. In Dorset, records of this species date as far back as 1826, and its status is of a fairly regular, but often low-density immigrant whose total numbers vary annually between zero and one thousand. It has been recorded in twenty-five of the past twenty-seven years, and in every month apart from December, January and March. Many of those reaching the county are likely to have originated from sources south of 35^°N where the species is at least double-brooded. However in 2003 and more especially during 2006, it seems that the autumn brood comprised home-grown examples too following on from long hot immigrant-rich summers. Observations of individuals with pale straw-coloured forewings are few and denote a rapid life-cycle in high temperatures typically in desert conditions. A northward expansion of populations across Europe during the summer probably accounts for the steady increase in numbers as the year progresses, as it does for several other immigrant species. The only, old, record of a larva was one found in tomatoes imported from Portugal.

2401       Heliothis viriplaca (Hufnagel 1766) MARBLED CLOVER     RDB3

A declining species in south-east Britain, now restricted to a handful of counties in south-east England and East Anglia, the larva feeding on the flowers and seeds of herbaceous plants. In Dorset, there is slim evidence to support a resident status for this species. Any colony that was once established has long been extinguished by the loss of unimproved herb-rich grassland habitat on chalky soils since the Second World War. The following record was from a typical habitat for the species: Badbury Rings, (S Scarsdale Brown). Core habitat at the site is now just 25 hectares in extent, it has become isolated by the surrounding grassland that has for a long time now been improved. The Marbled Clover and the Shoulder-striped Clover₂₄₀₂ were separated into two distinct species in 1938, and records prior to this date were all referred to as Marbled Clover Heliothis dipsacea. Diagnostics include: dark basal streak absent; inner edge of dark median band meets basal edge of forewing almost at a right angle, not 45 degrees.

All records below refer to immigrant moths seen at light unless otherwise stated; the majority backtrack to central northern Europe. The second example in 1995 was disturbed from its preferred unimproved herb-rich chalk downland habitat, but was probably a remnant from the notable immigration a week earlier which yielded the example trapped at Arne; no other moths have been seen on Melbury Down either before or since: Dorchester, at light on 16 June 1951 (Dr A Lisney), Scar Bank, at light on 6 August 1934, 14 August 1947, 26 July 1948, 19 August 1949 (A Russell), Melbury Down, by day on 9 August 1995 (P Davey), Arne, at MV on 1 August 1995 (B Pickess) – see Portland₂₀₉₉ account for weather map, West Moors, at MV on 8 August 1997 (B Baker).

 2402       Heliothis maritima (Graslin 1855) SHOULDER-STRIPED CLOVER     RDB3

Two races of this species have been noted in Britain, one is resident and the other is an immigrant. As stated above, the difference between the Marbled Clover₂₄₀₁ and the Shoulder-striped Clover is the angled median line on the forewing of the latter. The difference between the two Shoulder-striped Clover sub-species is the absence of a basal streak on the forewing of ssp. bulgarica.

ssp. warneckei Boursin 1964

A rare and decreasing species confined to the southern counties of Surrey, Hampshire and Dorset, the larva feeding on the flowers of heather (Calluna vulgaris), ling (Erica cinerea), cross-leaved heath (Erica tetralix), plus the seed heads of bog asphodel (Narthecium ossifragum). In Dorset, the moth was locally abundant on damp heathland across the Poole Basin: Bloxworth Heath, forty in 1851, forty-two in 1853, one hundred and forty-four in 1855 (O Pickard Cambridge), but following the afforestation of much of the county’s heathland, the species has declined dramatically, and there are very few recent records. It flies fast in sunshine over its habitat and on the warmest nights becomes active when it may occasionally visits light traps and sugar. The Heathland Implementation initiative, currently underway, has as its primary goal the re-creation of large tracts of open heath across the Poole Basin. Large areas of damp heath that were previously block-planted with conifers by the Forestry Commission will then become available to the species once more, and populations will hopefully respond as a result. A primary recommendation is the continued monitoring of this species to quantify year on year trends in response to the greater availability of damp heath.

ssp. bulgarica (Draudt 1938)

This subspecies is resident in south-eastern parts of Europe and has been seen on one occasion in Britain, on the Kent coast by day on 20 August 1947. The larva feeds on field scabious (Knautia arvensis), teasel (Dipsacus spp.) and chicory (Cichorium intybus). A potential second ssp. bulgarica was trapped at Scar Bank on 14 August 1938 by A Russell (see photo). The basal streak is missing on this example (the antenna unfortunately masks the critical region in the photo); the date is rather late for resident ssp. warneckei and the trap site more than five kilometres from core damp heathland habitat. An easterly airflow from central Europe was established a few days prior to the capture date.

2403       Heliothis peltigera (Denis & Schiffermüller 1775)      BORDERED STRAW

A regular immigrant species from southern Europe and north Africa, more often recorded in southern coastal counties and becoming progressively scarcer further north, the polyphagous larva feeding on various herbaceous plants. In Dorset, the moth has been recorded in all but four of the past twenty-one years, and in every month apart from November, December and March. The bivoltine brood pattern is partially obscured by influxes of moths from different latitudes emerging at different times. The moth visits the county usually as singletons, but in some years relatively high numbers arrive, even in a single night. This was the case in 1996 (see the June peak in graphic); the event is discussed in the account of the Small Mottled Willow₂₃₈₅. A second peak occurred during the third week of August 1996 coincident with the arrival of notable immigrant Lepidoptera species. However, small numbers of moths were being recorded from the beginning of August and this continued through to the second week of September. These were probably home-grown second generation moths, and the discovery of one larva was found in the wild feeding on rest harrow (Ononis repens) on Chesil Beach on 7 July 1996 by J Chainey and R Cook, supports this.  

An account in a diary of a successful search for larvae follows: “Went by 11:47 train to Swanage where I was joined by B Nevinson and E Nevinson. We worked the hollows on the south cliff between Peverill Point and Bellevue restaurant and between us got altogether two dozen of various sizes and colours. They feed only on the flowers of Ononis repens, and I am told, are best found, when feeding, in middle of morning in sunshine or in the evening.” (Reverend E Bankes, 24 July 1894). In 1906, following a largescale immigration of many lepidoptera species in late May, Bankes searched Peverill Point and Winspit, and found forty-six and one hundred and fifty larvae on 23 July and 1 August, respectively, again feeding on common restharrow.

Like the Scarce Bordered Straw₂₄₀₀, many examples that reach the county are likely to have originated from sources south of 35^°N where the species is at least double-brooded, and in the sub-tropics it is most probably continuously brooded. The forewing ground colour tends to vary as function of the temperatures experienced by the pupa. High temperatures of ~30^°C produce pale-coloured moths, and low temperatures ~5^°C produce dark-coloured moths; the very palest trapped in the first half of the year, theoretically originate from the African continent, the darkest, often encountered in the late summer, are likely to have developed nearer to home in cooler climes.

2404       Heliothis nubigera (Herrich-Schäffer 1851) EASTERN BORDERED STRAW

A very rare immigrant species and first recorded in Britain in 1958 and then in 1992, but with increasing frequency this century. It is headquartered in the sub-tropics including north Africa, and is an immigrant to southern Europe, the larva feeding on globe thistle (Echinops exaltatus) and bean caper (Zygophyllum fabago). On 9 May 1958 a south-westerly airflow brought the first British example to Dorset. A further four examples have been recorded in recent years at light traps in the county, and all but one are likely to have originated south of 35ºN over north-west Africa: Iwerne Minster, on 9 May 1958 (H Moore), West Bexington, on 25 June 2003, 12 August 2006 (R Eden), Durlston, on 14 May 1992 (B Skinner), 1 June 2006 (P Davey). However, the second example of 2006 (see photo) may well have been a local-bred specimen due to its amazing dark colouration; a persistent northerly airflow precluded the possibility of immigration during the first fortnight of August. The moth is similar to Scarce Bordered Straw₂₄₀₀ and Bordered Straw₂₄₀₃. Diagnostics include, respectively: a series of conspicuous dots parallel to edge of wing – Bordered Straw has a single prominent black dot close to the tornus; more contrast between ground colour and colour of sub-terminal band – Scarce-bordered Straw tends to be unicolorous.

2405       Schinia scutosa (Denis & Schiffermüller 1775) SPOTTED CLOVER

A very rare immigrant species seen less than fifty times in Britain, headquartered in eastern Europe, in North Africa and southern Iberia, and an occasional transitory resident in central and southern Europe. The larva feeds on field wormwood (Artemesia campestris) and goosefoot (Chenopodium spp.). In Dorset, the moth has been seen on one occasion. “One in my garden. It was feeding in bright sunshine on a flowering plant, and although only about three feet from me, was very wary, it went into the next garden. I went in for a net, but though I followed it into the next garden, it would not give me a chance to net it.” (W Parkinson Curtis): Branksome, by day on 23 July 1945. Of the British all-time total, thirty were seen in south-west England in May 1943 together with huge numbers of Striped Hawk₁₉₉₀; southern Iberia or Morocco were likely sources for this evidently spectacular immigration.

2407       Eublemma ostrina (Hübner 1808) PURPLE MARBLED

A rare immigrant species that is resident in the Mediterranean and the north African regions and a transitory resident in central Europe, the larva feeding on the flowers and seedheads of carline thistle (Carlina vulgaris). In Dorset, the moth is a rare immigrant and transitory resident that tends to be recorded from the coast. A number of larvae were found on Portland on carline thistle in August 1999; this is the only instance of residency for the species to date, and, as there was no opportunity for immigration for any of the adults seen in 1983, 1998 and 1999, it may be that the moth is a more frequent transient resident than previously thought, particularly on unimproved grassland sites on Purbeck and on Portland where its foodplant is relatively common. All (mainly) light trap records follow: Briars Wood, on 6 July 1998 (J Astley), Upwey, on 19 June 2000 (P Harris), Portland, on 17 June 1983 (A Pickles), 13 October 1990 (R Darlow), on 18 June 1983 (W Coster), 25 June 1983 (J Walters), 20 and 21 May, 9 and 19 August, 23 September 1992, 20 October 1995, 20 May 1998, 14 June 1999, 24 August 2003 (M Cade), Southwell, two larvae on carline thistle on 9 August 1999 (Dr P Sterling), Silklake Quarries, two larvae on carline thistle on 9 August 1999 (Dr P Sterling), Kingston, on 10 October 2006 (P Benham), Winspit, in 1930 (F Whitehead), Stoborough, on 5 October 1976 (B Withers), St Albans Head, two on 27 May 1992 (P Davey), Woolgarston, on 21 May 1992 (R Burt), Durlston, on 14 May 1992 (B Skinner), 25 May 1992 (D Brown), 26 May 1992 (Dr J Clarke), 13 October 1995 (R Plowman), 2 on 26 June 2003 (P Davey, S Nash), Swanage, on 21 August 1880 (Reverend E Bankes, Reverend C Digby), on 11 June 1999 (R Cox), Studland on 2 October 1990 (D Brown).

2408       Eublemma parva (Hübner 1808) SMALL MARBLED

A rare immigrant species that is resident in southern Europe and north Africa, and a transitory resident in central and northern Europe, the larva feeding on the ovaries and nectaries of common fleabane (Pulicaria dysenterica) and ploughman's-spikenard (Inula conyzae). In Dorset, this diminutive moth (for example, half the size of the micro Nomophila noctuella₁₃₉₈) is a rare immigrant and transitory resident, recorded at light traps chiefly from the coast: West Bexington, on 1, 2, 6, 9, 10 July 1998, 25 June 2003, 24 August 2003, 26 June 2006, 22 October 2006 (R Eden), Kingcombe, on 16 June 2006 (Dr P Sterling), Portland, on 7 September 1989 (M Rogers), on 15 October 1995 (N Hall), on 26 June 1996, 7 July 1998, 5 September 2005, 13 June 2006, three on 22, 24 and 26 July 2006, 7 August 2006 (M Cade), Church Ope Cove, on 23 July 1982 (B Withers), Broadway, on 21 July 2006 (P Harris), Preston, on 30 June 2003 (R Lambert), Gillingham, on 13 June 2006 (G Hopkins), Durlston, on 13 October 1995 (Durlston Country Park), Scar Bank, on 17 September 1947 (A  Russell).

However, there was no opportunity for immigration on any of the 1982, 1996 and 1998 dates, and in that latter year, larvae were found in the flowerheads of common fleabane growing abundantly in the ditches and damp clay meadows next to Chesil Beach. Searches were prompted by the occurrence of the five West Bexington adults trapped three weeks earlier: West Bexington, twelve larvae on fleabane on 26 July 1998 (Dr P Sterling). Although there was no prospect of immigration during the first week of July, the adults may have been the offspring from immigration during May. A second rare immigrant common fleabane-feeding species, the micro Tebenna micalis₃₈₆, was also recorded as an adult and as a larva during 1998 in Dorset, and it seems likely that both species were present in the original immigration.

The following is an account of the first moth to be caught in Dorset, at Wych in 1892: “As I was walking close to the edge of the water at about 6pm. I disturbed it out of the rushes and grass, and it settled within a foot of the edge of the water and let me get my net behind it - a most necessary move since the strong breeze was blowing straight off shore and across the water. I then bent down to look at it, whereupon it flew up and the wind carried it safely into the bottom of my net.” (Reverend E Bankes): Wych, netted by day within a foot of the edge of Poole Harbour on 8 June 1892.

2409.1   Eublemma purpurina (Hübner 1808) BEAUTIFUL MARBLED

First recorded in Britain in 2001; however, this specimen was not positively identified until 2004, when in the summer of that year a further twenty-two examples appeared across mainly south-western counties of England. This exquisite moth is resident in the Mediterranean and the north African regions, the larva feeding on the flowers and seedheads of carline thistle (Carlina vulgaris). The four Dorset (light trap) records are: West Bexington, on 31 August 2005 (Dr J Clarke), Portland, on 9 and 10 August 2004 (M Cade), Cheyne Weare, on 20 August 2001 (G Senior). All are likely to have originated from the region of the western Mediterranean. This species is rather similar to Purple Marbled₂₄₀₇. Diagnostics include: the absence of a dark basal streak; median line sharply angled as it approaches costal edge.

2410       Protodeltote pygarga (Hufnagel 1766) MARBLED WHITE SPOT

A local species found mainly in south-east England, and absent from northern England and Scotland, the larva feeding on purple moor-grass (Molinia caerulea) and false brome (Brachypodium sylvaticum). In Dorset, the moth is locally abundant in wet heaths, conifer plantations and bog habitat in the Poole Basin where purple moor-grass is dominant. Elsewhere, the moth occurs at low density in wooded localities, and in these situations false brome is one of the host foodplants. Singletons occasionally turn up at light traps elsewhere and these are likely to be dispersed examples from woodland or heathland. The following light trap records are likely to be partial second generation moths: Puddletown, on 13 September 2003 (H Wood Homer), Shaggs, on 11 October 2007 (L Hill), Chase Wood, on 2 September 1997 (P Davey), Arne Wood, on 29 September 1984 (B Pickess).

2412       Deltote uncula (Clerck 1759) SILVER HOOK

A local fen, bog, heath and moorland species in Britain, the larva feeds on sedges and grasses. In Dorset, the moth is at low density in wet heathland and mire (the same habitat occupied by the Small Grass Emerald₁₆₇₀), falling within the confines of the Poole Basin. “Few suitable localities exist in the county, and it is not common in these, nor present in all of them.” (W Parkinson Curtis ms). Wood-sedge (Carex sylvatica) and tufted hair-grass (Deschampsia cespitosa) are the two host foodplants named in texts, but these tend not to be found in an acid bog biotype in the county. Three sedges that occur frequently on the sites where moths are found are: common yellow sedge (Carex viridula oedocarpa), carnation sedge (Carex panicea) and star sedge (Carex echinata).

2414       Emmelia trabealis (Scopoli 1763) SPOTTED SULPHUR

A species of herb-rich fields and waste ground that occurred in the Breck district of east Anglia until 1960, and is now presumed extinct, the larva feeding on the flowers and leaves of field bindweed (Convolvulus arvensis). In Dorset, the moth has been recorded on one occasion: Scar Bank, to dining room light on 28 July 1947 (A Russell). The moth was likely to have been an immigrant from eastern France transported to the UK on south-easterly winds. Abroad, the moth is found in suitable habitat throughout southern, central Europe, south Sweden and eastern Denmark.

2415       Acontia lucida (Hufnagel 1766) PALE SHOULDER

A very rare immigrant species seen once in the nineteenth century and five times in the 1990s, but with increasing frequency subsequently, the larva feeding on field bindweed (Convolvulus arvensis), mallow (Malva spp.) and marsh mallow (Althaea officinalis). In Dorset, the moth has been recorded from light traps on six occasions; half of these have been from R Eden’s traps: West Bexington, on 5 August 1994, 19 August 1996, 14 August 2004 (R Eden), Portland, on 1 September 2005 (Dr J Clarke), on 10 August 2004 and on 25 July 2006 (M Cade). Abroad, the moth is found in suitable fallow habitat (from which it is easily walked-up during the day), throughout central and southern Europe, and North Africa.

 2418       Earias clorana (Linnaeus 1761) CREAM-BORDERED GREEN PEA     Notable/Nb

A local wetland species mainly in south-east England and East Anglia, the larva feeds within spun terminal shoots of willow and sallow (Salix spp.). In Dorset, the moth is frequent in wetland across the Poole Basin where it colonises sallow-rich heathland, fens and river valleys. It is also locally frequent in coastal situations on the Fleet, at Radipole and at Lodmoor, and in Christchurch Harbour. Dispersed singletons are very occasionally trapped some distance away from core habitat. A partial second generation appears in most warm summers from early August onwards. The species is well established in the Poole Basin, and threats posed to its sallow-rich habitats are considered to be minimal, but maintaining viable stocks of sallow on wetland reserves would undoubtedly be beneficial to the species in the county.

2420       Earias insulana (Boisduval 1833) EGYPTIAN BOLLWORM

A very rare immigrant species seen twice in Britain during the 1960s, the polyphagous larva favouring members of the mallow (Malvaceae) family. Abroad, this species is found in the tropics and sub-tropics, and closer to home in the Mediterranean region. It is a serious pest of cotton (Gossypium sp.), a genus within the mallow family. The larva causes most damage by boring into green bolls, destroying the fibre and consuming seeds and in extreme cases can destroy all the bolls in a crop. In Dorset, the moth has been seen on one occasion: Portland, at MV light on 24 August 1999 (M Cade). The moth is similar to the Cream-bordered Green Pea₂₄₁₈. Diagnostics include: wings held flat against side of abdomen; angled dark green crosslines towards the edge of the forewing; not ‘cream-bordered’.

2420.1   Earias vittella (Fabricius, 1794) SPOTTED BOLLWORM

A species found once in Britain: Durlston, at MV light on 15 June 2003 (S Nash). The moth has a similar range to the Egyptian Bollworm₂₄₂₀, occurring throughout the tropics and sub-tropics. It too is a serious pest of cotton but has apparently developed a resistance to pesticides designed to control it. Given that the surface winds backtrack to central Europe, it seems likely that both the Egyptian Bollworm and the Spotted Bollworm were transported for much of their respective journeys in airflows at medium to high levels from sources in Iberia or North Africa. An Eastern Bordered Straw₂₄₀₄ was trapped on the Scilly Isles on 16 June 2003.

CHLOEPHORINAE

2421       Bena bicolorana (Fuessly 1775) SCARCE SILVER-LINES

A widespread species in southern Britain, and absent in the north, the larva feeding on oak (Quercus spp.).  In Dorset, the moth is local and usually at low density in woodland and parkland where there are good numbers of mature oak trees; populations are greatest in old oak woods. Elsewhere and particularly in open habitat, it is seldom encountered.

2422       Pseudoips prasinana (Linnaeus 1758) GREEN SILVER-LINES

A widespread species in southern Britain, but local in Scotland, the larva feeding on oak (Quercus spp.), beech (Fagus sylvatica), hazel (Corylus avellana) and birch (Betulae spp.), less frequently on other deciduous tree species. In Dorset, the moth is more widespread than the Scarce Silver-lines₂₄₂₁, due to the greater availability of food sources, and is usually at low density wherever there are deciduous trees. It rises to frequent in the old oak and birch woods that still remain a feature of the landscape in the north-east of the county. The following record refers to a second brood example trapped at the end of a hot summer: Milton on Stour, on 11 September 2006 (J Burge).

2423       Nycteola revayana (Scopoli 1772) OAK NYCTEOLINE

A local species in southern England, rare elsewhere, the larva feeding on oak (Quercus spp.). In Dorset, the moth is at low density and found in a wide range of habitats, most often in woodland. The moth has been trapped fairly regularly at Durlston, and in this locality evergreen oak (Quercus ilex) is a likely host plant. It has also been recorded from coastal situations where there is little or no oak, and dispersal or immigration is suspected for many of these: Eype’s Mouth, on 13 October 2008, West Bexington, on 21 July 2000, 19 January 2003, 8 July 2003, 12 and 20 February, 20 March, 13 April 2004, four between 20 and 26 July 2004 (R Eden), Portland, on 17 July 2006, 8 October 2006, 7 April 2007, 11 August 2007 (M Cade), Studland Heath, on 21 September 1989 (P Davey), Shell Bay, on 1 October 1990 (P Davey).

The national norm is of a single brood emerging in late August and September before hibernating and becoming active once more between March and May. In Dorset, the moth is double brooded, with a discrete generation between late June and mid-August that is on average twice as large as the winter brood. The post-hibernation population is one and a half times larger than that observed during the autumn, and a partial spring emergence is suspected. The small peak in November may be a partial second brood spawned by the July moths, and the small peak in February corresponds with the winter immigration of 2004.

2423.1   Nycteola asiatica (Kruilkovsky, 1904) EASTERN NYCTEOLINE

A very rare immigrant species first seen in Britain in 1993 and just a handful of times subsequently, the larva feeding on sallow and willow (Salix spp.) and poplar (Populus sp.). Abroad, this species is found across much of southern, central and eastern Europe and across Scandinavia. In Dorset, the moth has been seen on one occasion: Weymouth, at MV light on 3 September 2005 (Dr P Sterling). This arrival of this example coincided with a south-easterly airflow from the region to the north of the French Alps. The moth is superficially very similar to the Oak Nycteoline₂₄₂₃ and over-winters in the adult stage too. Diagnostics include: less variable with a glossy- grey ground colour; a squarer apex (a similar difference exists between Chestnut₂₂₅₈ and Dark Chestnut₂₂₅₉); a slightly broader wing; usually prominent dark and fine thrice-angled cross lines.

2425       Colocasia coryli (Linnaeus 1758) NUT-TREE TUSSOCK

A widespread woodland species in Britain, the larva feeding on beech (Fagus sylvatica), hazel (Corylus avellana) and birch (Betulae spp.), and other deciduous trees. In Dorset, the moth is widespread and ranges from frequent to common in beech plantation and woodland containing substantial hazel understorey, to occasional in open habitat. The peak of the second brood is roughly one third smaller than that of the first brood. Potential third brood examples recorded in warmer than average summers follow: Iwerne Minster, at MV on 9 October 1955, 25 September 1967 (H Moore), Shaggs, at MV on 27 September 2001 (M Parsons).