NOTES AND COMMENTS ON SOME SUFFOLK MOTHS IN 1999

NOTES ON SOME SUFFOLK MOTHS, 1999

81

NOTES AND COMMENTS ON SOME SUFFOLK MOTHS IN 1999 M. R. HALL Despite the perceived wisdom among the county’s lepidopterists during the season that 1999 was a “poor year” there were several notable records to offset the gloom caused by cool conditions and the apparent decline in the numbers of many species of moths. The re-discovery of Hemaris tityus (L.), narrowbordered bee hawk-moth (Plate 9), in the north west of the county is of national significance. This moth, which is difficult to distinguish from its relatively common close relation Hemaris fuciformis (L.), broad-bordered bee hawk-moth, in the field, was reported by Musgrove and Armitage (2000) and sightings of the adult insect in May were subsequently re-inforced by successful searches of Devil’s-bit Scabious, Succisa pratensis, for larvae. The narrow-bordered bee hawk-moth, which Morley (1937) described as “unaccountably and excessively local” with but a single site to the south of Thetford as his sole county record, has been declining throughout the United Kingdom and this re-discovery in Suffolk is only the second colony remaining in the eastern half of the country (Prichard, 1999a). Equally encouraging for the county was the single Aetheria dysodea (D.& S.), small ranunculus, recorded at Landguard (NO) on 17 June. The identity of this specimen, of a species which was until recently thought to be extinct in Britain, was confirmed by Gerry Haggett. Although locally common in East Anglia, Kent and Surrey until the end of the nineteenth century it had disappeared from most of its range by 1912 with only sporadic records of singletons in the 1930s, 40s and 60s. It was last recorded in Suffolk in 1898 when it was taken at Bury and also bred from larvae (Morley, 1937). It was re-discovered in Kent in 1997 and in 1998 larvae were found feeding on Lactuca virosa, Great Lettuce, L. serriola, Prickly Lettuce and L. sativa, Garden Lettuce in a comparatively small area on the south bank of the Thames between Erith and Gravesend, which was one of its strongholds a century earlier (Agassiz & Spice, 1998). Whilst the provenance of this singleton from Felixstowe is unknown it could be a wanderer from further south. As the larval foodplants are to be found throughout Suffolk perhaps diligent inspection of likely looking specimens in light traps in June and July may reveal the small ranunculus is again breeding in Suffolk. However, on 23 September the Landguard recorders (NO) also reported a singleton of the dark form ab. ingenua of Aporophyla australis pascuea (Humph. & Westw.), feathered brindle. Although this species is well known from the Felixstowe/Thorpeness coast of Suffolk the melanic form is to be found regularly at Dungerness in Kent and Camber in East Sussex, so perhaps south-westerly winds blew both specimens into the county.

It was a day later, on 24 September, that a single Peribatodes secundaria (Esp.), feathered beauty (Plate 10), was recorded at Sicklesmere (SD) with its identity later confirmed by Rafe Eley. This is a species which is regarded as an adventive and migrant colonist and was first recorded in England from East Kent in 1981. It is now well established in Kent, where it is on the wing in July and August and it has also been recorded from Sussex and Surrey with

Trans. Suffolk Nat. Soc. 36 (2000)

82

Suffolk Natural History, Vol. 36

single specimens recorded in Essex in 1987 and 1997. This is the first sighting in Suffolk and a new county record. With the larvae feeding on Norway Spruce, Picea abies, and the larvae accepting other conifers in captivity, it is another species that may one day become established in Suffolk.

Quite remarkably it was about a month earlier, the fourth week in August, that another species was recorded in the county for the first time - technically the first of the two new county records. This was at Felixstowe (JN) and was Eupithecia phoeniceata (Rambur), Cypress pug. It is a migrant and possible adventive colonist on Monterey cypress, Cupressus macrocarpa, and other garden Cupressaceae. This Mediterranean species was first recorded in England from west Cornwall in 1959 and is now widespread along the southern coast to Kent and inland to Surrey, the London area and Essex. It has been recorded as far north as Warwickshire and may already be established in Suffolk and waiting to be recognised at other sites in the county!

Probably the most unlikely record for the year was another August arrival.

Technically another new county record and probably also a first for Britain, the specimen of Therestra nessus, yam hawk-moth, which a Mr. Fountain found in Felixstowe and passed to David Lampard almost certainly had an assisted passage from its native Orient. Tony Prichard (1999b) carried out some excellent detective work with the help of Martin Honey from the Natural History Museum to identify this moth and determine its probable origin, but it is unlikely to establish in Suffolk without significant global warming!

During the year there were several other migrants, which it is assumed arrived unaided, and as usual the most spectacular was Agrius convolvuli (L.), convolvulus hawk-moth (Plate 11), which was reported from Nowton (RE), Sizewell Belts (SMG), and Knettishall Heath (MH). Hyles gallii (Rottem.), bedstraw hawk-moth, was also reported from a coastal site, at Minsmere (But.Con.), and this together with records from previous years and similar regular reports from coastal Norfolk sites fuel the speculation that this species may be a transient resident, if only locally, at the present time. The day-flying Macroglossum stellatarum (L.), humming-bird hawk-moth, was reported from Felixstowe (PK) and Ipswich (SG) and although I am sure there have been other sightings that have not yet been brought to our notice the paucity of records for a species that usually attracts a lot of casual attention is another indication that 1999 was generally a poor year for moth recording in Suffolk.

There was a scattering of records for Mythimna albipuncta (D.& S.), whitepoint, from across the county; Eye (PK), Ipswich Golf Club (NS), Sizewell Belts (SMG) and Nowton (RE) but autumn records for Peridroma saucia (Hubner), pearly underwing, were much fewer than usual with the species being seen only at Eye (PK) and Nowton (RE) and then only as singletons.

Agrotis ipsilon (Hufn.), dark sword-grass, was recorded from a few more places; Eye (PK), Thelnetham Fen (SMG), Sicklesmere (SD), Knettishall Heath (MH) and Nowton (RE) where a total of 13 came to light. Helicoverpa armiger (Hubner), scarce bordered straw, was also noted at Knettishall Heath and Nowton but only as a single moth at each site. Both Sicklesmere and Nowton were visited by Rhodometra sacraria (L.), vestal, where a total of four were recorded between the two sites. Usually one of the commonest of

Trans. Suffolk Nat. Soc. 36 (2000)

NOTES ON SOME SUFFOLK MOTHS, 1999

83

the migrants, Autographa gamma (L.), silver Y, did indeed make appearances at sites across the county with records from Felixstowe (JN), Monks Eleigh (AW), Ipswich (SG), Knettishall Heath (MH), Sicklesmere, Elveden, Eriswell and Bradwell Woods (SD) and Nowton (RE). Only Rafe Eley reported that numbers seen showed an increase on 1998. Two species closely related to the silver Y, Autographa jota (L.), plain golden Y and Autographa pulchrina (Haworth), beautiful golden Y, which are not thought to be migrants, are perhaps indicative of some of the stresses currently affecting moth populations. Morley (1937) regarded both species as widespread and broadly distributed with the plain golden Y being the more common of the two and the beautiful golden Y as “somewhat scarce”. This would seem to have remained the balance until the last few years when the difference in “scarcity” has widened quite considerably with the plain golden Y still widespread and fairly common whilst the beautiful golden Y has all but disappeared over much of its previous range. Although both are found in the same habitats and credited with utilising the same larval foodplants, stinging nettle, dead-nettles and honeysuckle, the plain golden Y will accept a wider range of foodplants in captivity and this could indicate a greater ability to adapt to the changes that may be resulting from man’s interference with the environment.

Two Pyralids that are regular migrants, Udea ferrugalis (Hubner), rustydot pearl, and Nomophila noctuella (D.& S.), rush veneer were recorded from a handful of sites rather than the more usual profusion with Plutella xylostella (L.), diamond-back moth which is regarded as both a resident and breeding migrant being noted at just half a dozen sites in the county. Another migrant and transitory resident Loxostege sticticalis (L.) was recorded for the first time at Sicklesmere (SD) and this with other recent records from Breckland sites may indicate a current resident population following the migratory influxes a few years ago.

Subsequent to the report by Goater and Skinner (1995) that a saltern form of the sandhill rustic, Luperina nickerlii (Freyer) had been found to occur in south-east Suffolk (as well as a number of localities on the coasts of Essex and Kent), a specimen of L. nickerlii demuthi Goater & Skinner, was recorded from Landguard in 1998 (PK) but confirmation of its identity was not available in time for inclusion in the notes for 1998. Morley (1937) dismissed records from St. Annes and along the south coast as “little more than immigrants” and an earlier record from the Suffolk coast, taken in 1972 (Goater & Skinner, 1995), was un-recognised at the time as was the only other Suffolk record, a single moth taken at Nowton by Rafe Eley in 1968, which remained unidentified among a series of the very similar Luperina testacea (D.& S.) - flounced rustic for several years. The discovery of another specimen at Boyton Marshes in 1999 (SMG), after extensive and diligent searching at suitable sites along the coast, adds to the knowledge of the Suffolk distribution of this sub-species.

Following records of the Pyralid Platytes alpinella (Hubner) from four Breckland sites in 1998 (Hall, 1999) it was again recorded inland, from West Stow Country Park (SMG) in 1999. together with another record a little nearer to the coast at Ipswich Golf Club (NS), as well as from Minsmere (But. Con.).

Trans. Suffolk Nat. Soc. 36 (2000)

84

Suffolk Natural History, Vol. 36

Recent (Goater, 1986) and comparatively recent (Beirne, 1954) English literature on Pyralids indicates that this species is very local, rather uncommon, and restricted to coastal sandhills from Lincolnshire round to Devon (and also the Isle of Man) and it is undoubtedly this perception of its distribution and occurrence that led to its provisional RDB3 status. However Barrett (1905), who records it first being taken “in these Islands” near Portsmouth in 1871, lists a number of coastal sites for this species and adds “but so far as I know, not elsewhere in the United Kingdom”, also says “Abroad it frequents sandy districts inland, as well as on the coast”. This point is made even more forcefully by Leech (1886) who puts the distribution for Crambus alpinellus, Hb. (an earlier name) as frequenting sandy places in firwoods (among Scots Pine) and also coastal sandhills. Palm (1986) gives the Scandinavian distribution as “general” but most often in small numbers and inhabiting dry, sandy places but also open woodland and on meadows. We should, perhaps, not regard this uncommon species as one of the coast with other sightings as exceptional, but instead look to find it in suitable habitats right across the county. Another species that has been regarded as a Breckland speciality with scattered records from around the coast and elsewhere across the county, Scopula rubiginata (Hufn.), tawny wave, was also recorded from Ipswich Golf Club (NS) on two occasions with a further sighting at Nowton (RE). These, together with records from earlier years, may again indicate a wider and more general distribution than presently attributed to this species.

A species that Morley described as “local but quite generally distributed”, Anania verbascalis (D.& S.), seems to be only local among Wood Sage, Teucrium scorodonia that is growing in open country such as heaths, open conifer stands and shingle and the records in 1999, from West Stow Country Park (SMG) and Knettishall Heath (MH) bear this out. Nevertheless, it should be more widespread than current records indicate. The Breckland rarity, Lithostege griseata (D.& S.), grey carpet, although very much limited by the distribution of its only proven larval foodplant, Flixweed, Descurainia sophia, has been more numerous of late with numbers being recorded at Pashford Poors (SMG), Eriswell and Icklingham (SD), and Nowton (RE). A singleton of Stilbia anomala (Haworth), the anomalous, another species that is periodically found in the Breck, although it is more commonly noted from northern heaths and moors, was reported from Eriswell (SD det. RE). The obvious larvae, either brown or frequently bright green, may been found nocturnally feeding high on stems of Wavy Hair-grass, Deschampsia flexuosa, and searching for these in March or early April could be more rewarding than attempting to record the adults at light. Another species that seems to be restricted to the north west of the county, Idaea muricata (Hufn.), purplebordered gold, was recorded from West Stow Country Park (SMG). It is a species of fenland, mosses and damp heathland and its continued presence in this part of the county shows how valuable the rivers and meres (and adjoining wetlands) within Breckland are to sustaining its diversity of both fauna and flora. As well as continuing records from Felixstowe (JN) the related species Idaea rusticata atrosignaria Lempke, least carpet, was also found in Ipswich (SG) and at Ipswich Golf Club (NS) and now seems well established within Suffolk.

Trans. Suffolk Nat. Soc. 36 (2000)

NOTES ON SOME SUFFOLK MOTHS, 1999

85

A moth that is, apparently, only of sporadic occurrence in East Anglia was suddenly very much in evidence in April. After a number of years when it seemed to be totally absent Orthosia miniosa (D.& S.), blossom underwing, became the “moth of the moment” by appearing at several sites within a few days. The first two were seen at Lower Holbrook (RS) on the 3rd with further specimens at Little Blakenham (SMG) on the 4th and Hollesley Common (SMG) on the 5th with two more at Rushmere (JH) on the 6th and 8th. With similar sightings in Norfolk at the same time the blossom underwing had obviously undergone a significant population “explosion” for, as yet, unknown reasons. Previous records within Suffolk include singletons at Ickworth and Needham Market before 1890, Ipswich in 1894, Kessingland in 1936, Nowton in 1948, Barking Wood in 1954, Needham Market 1961 and Walberswick in 1968 with a report of larvae being plentiful in Barking Woods in 1956 (Chipperfield, 1957). This last record together with that of a single adult recorded from the same wood two years earlier perhaps gives a clue to the dynamics of a species that is prone to have population explosions and every effort should be made to find both larvae (probably on oak) and adults in and around the sites listed above, in both 2000 and 2001.

Several common species continue at a comparatively low ebb and Noctua comes Hubner, lesser yellow underwing, is one that many recorders noted as still being much less numerous than a few years ago. The current decline was particularly noticeable at Nowton where Rafe Eley commented that he trapped considerably more of the usually sparse Noctua orbona (Hufn.), lunar yellow underwing, than its supposedly common relative. On the other hand species like Hypena rostralis (L.), buttoned snout, are more in evidence than formerly with the moth coming to light at Pashford Poors Fen (SMG), Ipswich Golf Club (NS) and Sicklesmere (SD). The usual reluctance of the buttoned snout to come to light belies how widespread and common it is, a fact that can be readily demonstrated by beating wayside hop, Humulus lupulus L., in June and July for the larvae. It is only the females of Arctia villica britannica Oberthur, cream-spot tiger, that are reluctant to come to light with males appearing at sites across the county. With the cream-spot tiger being recorded from Pashford Poors (SMG), Ipswich Golf Club (NS), Combs Wood (SMG), Hollesley Common (SMG), Cavenham Heath (But. Con.), Icklingham and West Stow (SD), and Knettishall Heath (MH), and in some numbers at times, it is obviously still flourishing at the moment. For other species like Spilosoma urticae (Esper), water ermine, which are much less numerous and widespread, scattered but regular records like the one from Hollesley Common (SMG) are probably equally indicative of a healthy population. In the last few years records of Herminia tarsicrinalis (Knoch), shaded fan-foot, have been forthcoming from an ever increasing number of sites within the county. This moth was reported from Cutlers Wood (SMG) as well as Ipswich Golf Club (NS) in 1999 and is undoubtedly still spreading through suitable habitats across Suffolk.

It is not always advisable to rely too heavily on generalised national habitat requirements as published in the literature when surveying or monitoring on a regional, or county, basis. Most of the books in regular use

Trans. Suffolk Nat. Soc. 36 (2000)

86

Suffolk Natural History, Vol. 36

today say that Apoda limacodes (Hufn.), festoon, is an inhabitant of mature oak or beech woodland and indeed the larvae do seem to be restricted to oak or beech. However, by far and away the majority of records for this species in Suffolk and Norfolk come from oak or beech in an open heathland situation.

In 1999 it was recorded from Knettishall Heath (MH), Ipswich Golf Club (NS), Martlesham Heath (But. Con.) and Cutlers Wood (SMG). Similarly Eilema sororcula (Hufn.), orange footman, which is also described as inhabiting mature oak or beech woodland was recorded from Knettishall Heath and Ipswich Golf Club. Undoubtedly these are woodland species over much of their range but the drier climate in the east, and in both cases being towards the extremes of their current range in Britain, may influence their requirements or the way the foodplants grow (or both) and dictate a somewhat different habitat type from the norm. Both Macrochilo cribrumalis (Hubner), dotted fan-foot, and Earias clorana (L.), cream-bordered green pea are described as being species of fenland, river valleys and other marshy places and yet the former was recorded at Knettishall Heath (MH) and Nowton Country Park (RE). Whilst this species, which is said to feed on sallow and a variety of wetland grasses and sedges, is well represented in the East Anglian fens and marshes it would also seem able to tolerate drier overall conditions provided it has access to suitably growing foodplants. The cream-bordered green pea seems almost to spurn the limits of its traditional habitats with records from Eye (PK), Monks Eleigh (AW), Ipswich Golf Club (NS), West Stow Country Park (SMG), Combs Wood (SMG), Sicklesmere (SD), Felixstowe (JN), Nowton (RE) and Thelnetham Fen (SMG) with several recorders commenting on how much more common and widespread this species has become in the last year or two.

Since it was confirmed as a Suffolk resident in the King’s Forest in 1993

by Rafe Eley, Eupithecia egenaria H.-S., Fletcher’s pug (pauper pug), has been discovered at a number of sites in the county but the sighting in Nowton Park (SD/RE) on 17 July must be as late as this species has been found on the wing at any of its localised sites in Britain. The adults more usually fly in May and June and this later flight time may indicate the beginning of apparently better synchronisation between the hatching of eggs and suitability of the flower buds of lime, Tilia sp., to be penetrated by newly hatched larvae.

Epirrhoe rivata (Hubner), the wood carpet was regarded by Morley (1937) as being more plentiful and general in Suffolk than probably anywhere in England and yet even though it does not seem to have suffered a decline nationally it has been only sparsely recorded in the county in recent years. The latest sighting at West Stow (SD/RE) is one of just a handful since 1990. One reason for this lack of records is probably the similarity of this species with Epirrhoe alternata alternata (Muller), common carpet, and the assumption by recorders that the slightly larger specimens with an unbroken white band on the forewing are just forms of the common carpet. I do urge everyone to look most carefully at such individuals and, if necessary, consult the Suffolk Moth Recorders to confirm identities in suspect cases. Similar confusion between the red-banded form of Xanthorhoe ferrugata (Clerck), dark-barred twin-spot carpet and Xanthorhoe spadicearia (D.& S.), red twin-spot carpet may be part

Trans. Suffolk Nat. Soc. 36 (2000)

NOTES ON SOME SUFFOLK MOTHS, 1999

87

of the explanation as to why there is currently such a difference in the recorded occurrence of these two species when not so long ago they were equally numerous and widespread. This variance is highlighted by records from Stan Dumican where he recorded 63 individuals of the red twin-spot carpet at five different sites and on the same nights saw only two dark-barred twin-spot carpet and these were both at the same site. It is very unlikely that such a big difference can be attributed to any single cause and I am sure Stan would distinguish between the red-banded form of the dark-barred twin-spot carpet and the red twin-spot carpet if he is looking for it, but it could be easily passed over when not expecting the form, especially when quickly checking through a trap at the end of an evening. A careful study of any suspect specimens may help to determine whether there has been a dramatic decline in the population of the dark-barred twin-spot carpet and whether there is also an increase in the proportion of the red-banded form.

As well as maintaining its numbers at all its coastal stations Polymixis lichenea lichenea (Hubner), the feathered ranunculus continues to expand is range inland with a dozen coming to an Ipswich garden (SG) and singletons travelling as far as Knettishall Heath (SMG) and Sicklesmere (SD). A further record of Cryphia muralis (Forster), marbled green, in Felixstowe (JN), the third in the last few years, poses the question as to whether this species is reestablishing itself in the county. Although Heliothis viriplaca (Hufn.), marbled clover, has been recorded from many and varied sites across Suffolk in the last ten years it was noted at only West Stow (SD) and Knettishall Heath (MH) in 1999. It is just such variations in distribution and occurrence that will indicate moths’ response to changes in the environment and the only way we can begin to understand the effects of such changes is to continue with careful and regular field observations and pass these records to either of the county recorders: Tony Prichard, 3 Powling Road, Ipswich, Suffolk, IP3 9JR and Jon Nicholls, 18 Berners Road, Felixstowe, Suffolk, IP11 9BD or to Martin Sanford, S.B.R.C., The Museum, High Street, Ipswich, Suffolk IP1 3QH. Do please send all the records you can to any of the above, whether they are for the current year or from a year or two ago - they are all valuable.

Acknowledgements I thank all those recorders whose records and notes have helped to compile this report: (But. Con.) Suffolk Branch of Butterfly Conservation, (SD) Stan Dumican, (RE) Rafe Eley, (SG) Steve Goddard, (JH) Jeff Higgott, (PK) Paul Kitchener, (JN) Jon Nicholls , (NO) Nigel Odin and Mike Marsh, (NS) Neil Sherman, (RS) Richard Stace, (SMG) Suffolk Moth Group, (AW) Arthur Watchman, and in particular those who provided additional comments on numbers and local fluctuations which have been so helpful.

References Agassiz, D. J. L. & Spice, W. M., (1998). The return of the Small Ranunculus.

Entomologist’s Rec. J. Var. 110: 229-232.

Barrett, C. G., (1905). The Lepidoptera of the British Islands, 10: 76. London: Lovell Reeve.

Trans. Suffolk Nat. Soc. 36 (2000)

88

Suffolk Natural History, Vol. 36

Beirne, B. P., (1954). British Pyralid and Plume Moths. London & New York: Fdk. Warne.

Bradley, J. D., (1998). Checklist of Lepidoptera recorded from the British Isles. Fordingbridge, Hants: D. J. & M. J. Bradley.

Chipperfield, H. E., (1957). Lepidoptera Notes : 1957. Trans. Suffolk Nat. Soc., 10: 210.

Goater, B., (1986). British Pyralid Moths. Great Horkesley, Colchester: Harley Books.

Goater, B. & Skinner, B., (1995). A new subspecies of Luperina nickerlii Freyer, 1845 from south-east England, with notes on other subspecies found in Britain, Ireland and mainland Europe. Entomologist’s Rec. J. Var. 107: 127-131.

Hall, M. R., (1999). Notes and comments on some Suffolk moths in 1998.

Trans. Suffolk Nat. Soc. 35: 81.

Leech, J. H., (1886). British Pyralides. London: R. H. Porter.

Morley, C., (1937). Final Catalogue of the Lepidoptera of Suffolk. Ipswich: Suffolk Naturalists’ Society.

Musgrove, A. M. & Armitage, M., (2000). Rediscovery of the Narrowbordered Bee Hawk-moth (Hemaris tityus (L.)) (Lep.: Sphingidae) in Breckland. Entomologist’s Rec. J. Var. 112: 75-76.

Palm, E., (1986). Nordeuropas Pyralider. Copenhagen: Apollo Books.

Prichard, T., (1999a). Narrow-bordered Bee Hawk-moth re-discovered in Suffolk. Newsletter, Suffolk Moth Group 17: 3-4.

Prichard., T., (1999b). Yam Hawk-moth (Therestra nessus) - first for Suffolk and the country? Newsletter, Suffolk Moth Group 17: 4-5 M. R. Hall (MH) Hopefield, Norwich Road, Scole, Diss, Norfolk IP21 4DY.

Trans. Suffolk Nat. Soc. 36 (2000)

A. W. Prichard S. Dumican

Plate 9: Narrow-bordered Bee-Hawk, Hemaris tityus (L.). This nationally scarce species was re-found in N.W. Suffolk in May 1999 feeding on Devil’s-bit Scabious, Succisa pratensis Moench. (p. 81 & 91).

Plate 10: Feathered Beauty, Peribatodes secundaria (Esper) at Sicklesmere, September 1999. First Suffolk record (p. 81 & 88).

S. Dumican Plate 11: Convolvulus Hawk-moth, Agrius convolvuli (L.), a regular migrant to Suffolk, was seen at several sites in 1999 (p. 82).