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INVASION OF DRAGONFLIES IN 1995 H. MENDEL & M. C. MARSH The long, hot and dry summer of 1995 (breaking several records; the hottest August ever!) will be remembered in future decades as an exceptional time for insect migration. The massive influx of dragonflies included two species not previously recorded in Britain - Crocothemis erythraea (BrĂźlle) Scarlet Dragonfly (previously recorded from the Channel Isles) on the Lizard Peninsula in Cornwall, 7th August 1995 (Jones, 1996) and Sympetrum pedemontanum (Allioni) Banded Darter at a site on the southern edge of the Brecon Beacons in Powys, 16th-17th August 1995 (Silsby, 1995a, b). It is tempting to speculate that these individuals may have flown over East Anglia on migration westwards. However, many of the migrants recorded in western Britain quite likely had a different origin to those that entered Britain via the eastern counties. In Suffolk it was the invasion of Sympetrum flaveolum (L.) Yellowwinged Darter with lesser numbers of Sympetrum danae (Sulzer) Black Darter that will be remembered. It is likely that Sympetrum vulgatum (L.) Vagrant Darter also occurred in Suffolk but none of the records was confirmed. A report of Hemianax ephippiger (Burmeister) Vagrant Emperor dragonfly from Newbourn is presumed to be a case of mistaken identity and cannot be accepted. The immigration seems to have started on the 3Ist July and coincided with a large area of high pressure which became established over Scandinavia from 29th July, resulting in warm easterly winds which persisted for much of August, occasionally switching to the south-east or north-east (Tunmore, 1996). Interestingly, 'On July 31st hundreds [of S. flaveolum] were seen leaving the shores of Holland' (Silsby, 1995a). The immigration also included more familiar species - Aeshna mixta (Latreille) Migrant Hawker, Sympetrum sanguineum (MĂźller) Ruddy Darter and Sympetrum striolatum (Charpentier) Common Darter - that are normally resident in Britain. It is a pity, although understandable, that the excitement created by the appearance of so many rarities distracted attention away from these more familiar migrant species. Although S. danae and 5. flaveolum can usually be identified with confidence, S. vulgatum proved very difficult to recognise, even in the hand. In particular, it was not realised by many dragonfly enthusiasts that the black 'moustache' marking on the face (at the base of the frons and continuing down the sides of the eyes) which distinguishes S. vulgatum from S. striolatum is also found in S. sanguineum. Heath and Milford (in press) have critically examined the various characters that are used to separate the three species, using specimens recorded in Norfolk in 1995. None of the putative Suffolk S. vulgatum was critically examined in the hand and all of the records must be regarded as provisional and unconfirmed. The list of records below, arranged alphabetically by locality, includes only those species not normally found in Suffolk (Mendel, 1992), viz.
Trans. Suffolk Nat. Soc. 32 (1996)
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S. danae Black Darter Lost as a breeding species in Suffolk in the 1950s, the Single credible, although unconfirmed report since that time was from Walberswick National Nature Reserve in September 1988. Several specimens reported at that time may have been migrants. S. danae is restricted to acid bog habitats for breeding. Although such habitats are very scarce in Suffolk the species could easily re-establish itself at places such as Walberswick N.N.R. S. flaveolum Yellow-winged Darter Apart from a record for Easton Bavents TM5077 on 7th September 1994, when a Single cf was recorded by E. W. Patrick and J. M. Cawston (who photographed the specimen), the last record was on 14th August 1953 at East Bergholt. S. flaveolum has never before been recorded in such huge numbers. There is a defmite possibility that this dragonfly may become established as a breeding species in Britain following the 1995 immigration as it has, on a temporary basis, in the past. Between 1945 and 1947 it is believed that a breeding colony of S. flaveolum was established at Alderfen Broad in Norfolk (Ellis, 1948). It was probably killed off by the very severe winter of 1947-48. (See Plate 5) S. vulgatum Vagrant Darter According to Hammond (1983) there have been only eight British records for this species, none of them from Suffolk. Merritt, Moore and Eversham (1996) confirm that until 1995 there had not been a reliable record since 1946. (See Plate 6) The records below include a few from just outside the recording area of Suffolk (Vice-counties 25 and 26). It is certainly not exhaustive and readers are asked to advise the authors of additional records that may not have been considered. Grid references assigned by the authors are in Square brackets [ ], as are authors' comments. Aldeburgh 6th August - 3 c f c f S. flaveolum in wheat field, Aldeburgh Marshes, TM4556; 5 cfcf S. flaveolum at Church Farm estate (probably also 1 cf S. vulgatum but the record could not be confirmed), TM4657; 2 cfcf S. flaveolum in churchyard TM4656. W. J. Brame and E. W. Patrick. Benacre Ist August - S. flaveolum just to the south of Benacre Pits on a rough grass area near to the shore, TM534835. A. Watchman. 14th August - 4 cf Cf S. flaveolum, TM5382. R. Waiden. Covehithe 2nd August - Shoreline littered with dead insects [TM5281]; mainly ladybirds (Coleoptera: Coccinellidae) and Peacocks Inachis io L. but including a specimen of S. flaveolum (now in the Castle Museum, Colchester). J. P. Bowdrey. Dun wich 6th August - Several S. flaveolum on the saltmarshes behind the shingle seadefences TM4771. Almost certainly also several c f c f S. vulgatum (judging by the colour - a distinctive carmine red) but these evaded capture so the record must remain provisional. H. Mendel. lOth August - 3 cfc? and 2 9 9 S. flaveolum on salt marshes at Dunwich TM4770. A. P. Richards.
Trans. Suffolk Nat. Soc. 32 (1996)
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Felixstowe, Gulpher Road 6th August - Single S. flaveolum [TM2935].
M. James.
Felixstowe, Landguard Point 31st July/lst August - 1 cf S. flaveolum (specimen now in Ipswich Museum) caught in moth trap at Landguard Point TM2831 (trap operated from 9pm on 3Ist to 5am the following morning). Interestingly the trap also contained an adult male S. sanguineum - the two species are thought often to migrate together - and many migrant moths, eg. 455 Diamond-back Moths Plutella xylostella L. M. C. Marsh. 2nd August - 5 specimens of S. flaveolum counted at Landguard TM2831/ TM2832. M. C. Marsh and P. Holmes. 5th August - 2 cfcf S. flaveolum. M. C. Marsh. 1 Ith August - 1 cf S. flaveolum. M. C. Marsh. Felixstowe, Peewit Hill 2nd August - 2 cfcf S. flaveolum and 1 cf (mature) 5. danae TM2833/2933. W. J. Brame and M. C. Marsh. 3rd August - 5 cf Cf (2 teneral) S. flaveolum TM2833/2933. W. J. Brame and M. C. Marsh. 1 Q S. vulgatum (seen at close quarters but unconfirmed) and possibly 2 cfcf which would not allow close examination. W. J. Brame. 4th August - 1 cf (teneral) S. flaveolum. W. J. Brame 5th August - 4 c f c f . 19 S. danae [TM2833/2933], 6th August - At least 7 S. flaveolum (photographed by S. R. G.) at TM2833. S. R. Goddard and M. C. Marsh. lOth August - 1 cf S. danae (specimen now in Ipswich Museum), TM2933. H. Mendel. 26th August - 1 cf 5. flaveolum. W. J. Brame Felixstowe, Trimley St Mary, Fagbury Cliff 5th August - 1 cf S. flaveolum, TM2734. M. C. Marsh, lcf S. danae, [TM2734], M. T. Wright. 6th August - 1 cf and 3 Q 9 S. flaveolum, TM2734. S. H. Piotrowski, G. Mortimer and N. Odin. 1 9 .S'. danae, [TM2734], G. Moitimer. 1 Ith August - 1 cf S. danae, [TM2734]. G. Mortimer. Great Yarmouth (VC 27, East Norfolk) Although just outside the recording area of Suffolk (the vice-county boundary between East Suffolk and East Norfolk follows the R. Waveney and passes through Breydon Water), this 'hot-spot' of the migration deserves a mention as it is less than 1km over our border. Ist August - 'nine Yellow-winged Dariers were reported in Great Yarmouth Cemetery [TG5208]. On the morning of the 2nd August, there were around 100 and by the following evening the count had reached around 600. There were darters everywhere, perched on gravestones, on railings, on plant tips and on the branches of trees. In addition to the Yellow-winged Darters, there were Black, S. danae, Common, S. striolatum, Ruddy, S. sanguineum, and also small numbers of two other migrants, Red-veined, S. fonscolombei, and Vagrant, S. vulgatum, all congregated in the waterless cemetery' (Silsby, 1995b). S. fonscolombii was reported in error (J. Silsby, in lit.) and these initial counts, which
Trans. Suffolk Nat. Soc. 32 (1996)
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capture the excitement of the moment, are not entirely accurate. Heath (1996) has written a detailed and considered account of the influx of darter dragonflies into Norfolk. Two vouchers each of S. flaveolum and S. vulgatum, collected on 3rd August, are now in the Castle Museum in Norwich (A. G. Irwin, pers. comm.). 5th August - Still several dozen S. flaveolum (colour variable, some with hardly any yellow on the wings, a few with extensive yellow - 1 Q of latter form now in Ipswich Museum). Smaller numbers of S. vulgatum (mostly QQ but at least 1 c f , voucher in Ipswich Museum), S. danae, S. sanguineum, S. striolatum, and Aeshna mixta, mainly in the northern side of cemetery, TG5208. H. Mendel. Pittman (1996) visited the cemetery on the same day. Hopton-on-Sea 12th August - 'a female specimen [5. flaveolum] visited my garden [Mariners Park Close, TF5200] and settledfor an hour or so' (Brown, 1995). Ipswich, Purdis Heath 3rd August - Two specimens S. flaveolum on the golf course, TM213432 and TM213436 respectively. A. Watchman. Ipswich, Rushmere Heath 15th August - 1 cf S. flaveolum [TM2044],
S. H. Piotrowski.
Kessingland 5th August - Several male S. flaveolum on the seaward end of the main drain across Kessingland Level, TM5384. H. Mendel. Lound 5th August - 'On the 5th. August I saw around flfty specimens [5. flaveolum] at Lound waterworks with around sixty percent of them being males. On the 15th. August I spotted a pair in tandem close by one of the reservoirs and it therefore seems likely that at least some breeding may have occurred.' (Brown, 1995). On two occasions counts were in excess of 100 [TG40 /50], T. Brown. Martlesham 3rd August - 1 cf S. danae, pond on British Telecom site, TM2444. J. B. Higgott. Middleton 5th August - l c f X flaveolum, TM4268. M. C. Marsh. Minsmere [first few days of August] - 'some 400 [S. flaveolum] were seen offshore, flying northwards' (Silsby, 1995a). It has not been possible to substantiate this record which is said to be ' f r o m the worden'. It should be disregarded. 2nd August - 1 cf S. flaveolum on bushes by the sluice [TM4766], A. A. Butcher. 5th August - 4 cf and 1 Q S. flaveolum, TM4767. D. Fairhurst. 6th August - 31 cf and 1 9 flaveolum in the woodland rides near one of the reedbeds, TM4767. D. Fairhurst. 7th August - 29 cf cf and 8 QQ S. flaveolum, TM4767. D. Fairhurst. 8th August - 14 cf cf and 2 Q S. flaveolum, TM4767. D. Fairhurst. 15th August - 2 cf Cf S. flaveolum, TM4767. D. Fairhurst.
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North Warren (RSPB Nature Reserve) 4th August to 9th September - S. flaveolum recorded on coastal grazing marshes on many dates between these extremes with a maximum of 83 c f c f and 7 9 9 o n 9th August and a pair in tandem on l l t h August. S. danae recorded on 9th August (1 c f ) on freshwater, coastal grazing marsh and on 5th September (1 c f ) in a freshwater reedbed [TM4659]. An element of doubt associated with putative S. vulgatum sightings on the 9th, lOth and 17th August, Single males in each case, means that the records must remain provisional. All records [TM45], R. N. Macklin, D. Fairhurst and D. Thurlow. 12th August - 14 c f c f and 2 9 9 S. flaveolum-, cf in tandem with 9 S. striolatum in rushy field [TM45] (photographed by I. Dawson, who saw another specimen fly high and away to the NW). I. Dawson, R. N. Macklin, D. Fairhurst and D. Thurlow. Sizewell 2nd August - S. flaveolum (5 'red' and 1 'yellow'; 1 c? now in Ipswich Museum) and 1 cf Calopteryx splendens (Harris) Banded Demoiselle early in the morning ('kicked out of grass') along the shore, TM4763/4764. J. M. Cawston and E. W. Patrick. Sudbury (VC19, North Essex) 5th August - 2 c f c f S. flaveolum on the 'Common Lands', TL8641; a Single Cf the following day. A. A. Butcher. Thorpeness 31st July - S. flaveolum on Vegetation at base of sandy cliffs, TM477605. A. Watchman. Walberswick 5th August - 1 cf S. flaveolum, TM4873. M. C. Marsh. 9th August - 8 or 9 specimens of S. flaveolum, [TM47], Per C. S. Waller. Acknowledgements We thank the many naturalists who have sent in their records (and records submitted to them) for making this review possible - Ms C. Anderson (Assistant Warden, RSPB Minsmere), J. P. Bowdrey (Assistant Curator of Natural History, Colchester Museums), W. J. Brame, T. Brown (Great Yarmouth Naturalists' Society), A. A. Butcher, J. M. Cawston, I. Dawson, D. Fairhurst (Assistant Warden, RSPB North Warren), S. R. Goddard, J. B. Higgott, P. Holmes (Warden, Landguard Bird Observatory), Dr A. G. Irwin (Keeper of Natural History, Norwich Castle Museum), M. James, R. N. Macklin (Warden, RSPB North Warren), G. Mortimer, N. Odin, Dr A. J. Parr (British Dragonfly Society, Migrant Dragonfly Project), E. W. Patrick, S. H. Piotrowski, A. P. Richards, Mrs J. D. Silsby (Editor, British Dragonfly Society Newsletter), D. Thurlow, R. Waiden, C. S. Waller (Warden, Walberswick National Nature Reserve), A. Watchman, Mrs J. Watchman, and M. T. Wright. We particularly thank Dave Fairhurst, Tony Irwin and Adrian Parr for helpful discussion about particular records and the migration in general.
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References Brown, T. (1995). A survey of the dragonflies of eastem Norfolk for the season 1995. Great Yarmouth Naturalists' Society. Ellis, E. A. (1948). Fauna and flora of Norfolk. Dragonflies. Trans. Norfolk NorwichNat. Soc., 16: 331-332. Hammond, C. O. (1983). The dragonflies of Great Britain and Ireland. 2nd ed. (revised by R. Merritt). Colchester: Harley Books. Heath, P. (1996). The 1995 Yellow-winged darter influx: a Norfolk perspective. Atropos, no. 1, pp. 12-17. Heath, P. J. & Milford, P. J. (in press). Records of Sympetrum vulgatum, new to the county Odonata list, and Sympetrum danae in east Norfolk, August 1995. Unpublished ms. (submitted to the Trans. Norfolk Norwich Nat. Soc. for publication in 1997). Jones, S. P. (1996). The first British record of the Scarlet Dragonfly Crocothemis ervthraea (Brßlle). J. Br. Dragonfly Soc., 12: 11-12. Mendel, H. '(1992). Suffolk Dragonflies. Ipswich, Suffolk Naturalists' Society. Merritt, R„ Moore, N. W. & Eversham, B. C. (1996). Atlas of the dragonflies of Britain and Ireland. London: HMSO. Pittman, S. (1996). Migrant species of Sympetrum in Norfolk, 1995. J. Br. Dragonfly Soc., 12: 11-12. Silsby, J. (1995a). The 1995 darter invasion. British Dragonfly Society Newslettern. 28, pp. 11-13. Silsby, J. (1995b). Wildlife reports. Dragonflies. British Wildlife, 7: 48-50. Tunmore, M. (1996). The 1995 Camberwell beauty Nymphalis antiopa (L.) influx. Atropos, no. 1, pp. 2-5. Howard Mendel, The Museum, High Street, Ipswich IP1 3QH
L
Mike Marsh, 5 Ennerdale Close, Felixstowe, Suffolk IP11 9SS
Trans. Suffolk Nat. Soc. 32 (1996)
Plate 5: Yellow-winged Darter, Sympetrum flaveolum (L.), large numbers of this normally rare migrant were seen in Suffolk in 1995 (p. 23).
Plate 6: Vagrant Darter, Sympetrum vulgatum (L.), a few of this rare migrant accompanied the invasion of Yellow-winged Darters (p. 23).