174 Entomologist's Rec. J. Var. 125 (2013) MYRMELEON FORM/CAR/US (L., 1767) (NEUR.: MYRMELEONTIDAE): AN ANT-LION NEW TO BRITAIN IDAVE COOKE, 2TIM NORRISS, 3LYNN FOMISON & 4COLIN W. PLANT 12 Clarence Cottages, Queens Road, Freshwater Isle o/Wight P040 9HD (E-mail: [email protected]) 240 Taskers Drive, Anna Valley, Andover. Hampshire SPll 7SA (E-mail: [email protected]) 3 Mount Pleasant, Parkstone Road, Ropley, Hampshire S024 OEW (E-mail: [email protected]) 414 West Road, Bishops Stortford, Hertfordshire eM23 3QP (E-mail: cpauk1 @ntlworldcom) Abstract The ant-lion Myrmeleon formicarius (Linnaeus, 1767) is recorded new to Britain from the Isle of Wight in August 2013. The possible origin of the insect is discussed. Keywords: N europtera, Myrmeleontidae, Myrmeleon formicarius. Introduction In a suburban area of Freshwater, at the western end of the Isle of Wight about 1.25 km inland from the south coast, DC runs a 125 watt MV Robinson-pattern moth trap regularly in his garden. During the night of Friday 23 August 2013, there had been a light north-west breeze throughout and amongst the 108 species recorded in the trap the next morning were several potential immigrants, such as 13 Plutella xylostella (L.), 10 Udeaferrugalis (Hb.), a single Agrotis ipsilon (Hufn.) (Dark Sword-grass) and 42 Autographa gamma (L.) (Silver Y). Evergestis limbata (L.) and Udeafulvalis (Hb.) were also recorded, but these are resident in the area. In the morning, there were many moths outside the trap including several Jersey Tiger Euplagia quadripunctaria (Poda) which is now abundant in many places along the south coast of the island. Upon the arrival of TN and LF to stay for the weekend, we started to empty the trap of its contents. Near the bottom of the trap TN noticed what he thought was an ant­ lion settled on one of the trays and so it was potted. A hasty picture taken on a mobile phone was sent straight away to Paul Brock who in tum e-mailed it to CWP; he responded with the information that this was a species of Myrmeleon (L.) and that on the basis of the wing venation and patterning could only be either M formicarius (L.) or M bore (Tjeder). Subsequent examination of additional photographs showing the colour pattern on the pronotum, together with a knowledge of the wing length, generated the response that (in absence of the actual specimen) in his opinion this was certainly M formicarius. In view of the extreme surprise that this species could migrate to Britain, a selection of images were e-mailed to colleagues in Europe who are familiar with this species Entomologist s Rec. J. Var. 125 (2013) 175 Plate 1. Myrmeleonformicarius (L.), Freshwater, Isle of Wight, 23.viii.20 13, leg. Dave Cooke, in coil. James Halsey. 1. Showing the venation on both fore and hind wings and the slightly falcate wing tips; 2. Entirely dark dorsal surface of pronoturn helps to distinguish this species from M bore; 3. Oblique lateral view of head and thorax showing colouration oflegs and other features; 4. Tn a natural repose, with a fern frond for scale (wing length = 34 mm). All photographs Dave Cooke. on a regular basis. The responses received from Dr Ferenc Szentkinily (Hungary), Dr Agostino Letardi (Italy), Dr Patrice Leraut (France), Dr Dusan Devetek (Slovenia) and Dr Levente Abraham (Hungary) supported the identification as M formicarills, although emphasised the need to distinguish carefully from M bore. Recognition According to Aspock et al (1980) the dorsal pattern of the pronotum is characteristic. These authors also discriminate between the two within their key on the basis of fore wing length, with M formicarius having a wing of 35 - 40 111111 and M bore smaller at 25-33111111. The cynical will be unsurprised that the Isle of Wight specil11enl11easures 34 1111ll. However, Feri Szentkiraly al so cOllll11ented that "The wing length o/antlions 11101 ' be variable, as Ijollnd in mv larger adult material collected by light trapping, consequently it is not a good key/or identification" . 176 Entomologists Rec. J. Var. 125 (2013) We are extremely grateful to Dr Levente Abraham for supplying photographs of set specimens of males of both M formicarius and M bore together with the following notes: M formicarius is larger species than M bore, the length of forewing usually is over 30 mm while M bore has less then 30 mm. The shape of forewing in the [Isle of Wight] picture is more similar to M bore than that of M formicarius. Forewing is narrower than that of M formicarius . ... The male of M bore has a pilula axillaris (Eltringham organ) in the base of hindwing; M formicarius has not got such an organ. The ectoproct of M bore has a bent, tooth-like processus ventrally while that of M formicarius is only an oval plate. In both sexes the dorsal segments of the abdomen of M bore have a narrow yellowish edge caudally while those of M formicarius do not. M formicarius usually flies from end of May to early July, M bore flies from the middle part of summer, mainly in the second part of July and in August. Overall, we are in no doubt that this captured specimen refers to M formicarius. An erroneous earlier record An earlier published report of Myrmeleon formicarius in Britain has been shown to be a misidentification of Euroleon nostras (Geoff. in Fourc.), which is resident on the East Suffolk coast (Plant, 1998a; 1998b, 1999, from which the following three paragraphs are quoted). "The earliest reference to British ant-lions (Neuroptera: Myrmeleontidae) in the literature appears to be that of Barbut (1781), who recognised "Myrmeleon formicarum" as a British species but gave no details. Stephens (1829), also included "Myrmeleon formicarum" as British, though he had never himself seen a British specimen and had presumably copied from Barbut's earlier work. Later (Stephens, 1835) he reconsidered the matter and concluded that the species was erroneously introduced as British by Barbut. Hagen (1858), stated that it was" ... almost certain that at least two species of Myrmeleon will be found in Britain, probably more", but provided no evidence to support that statement. McLachlan (1868) considered that " ... we have no native member of the handsome Myrmeleonidae in Britain". The first confirmed British record of an ant-lion came on 5 September 1931 at Gorleston, when a single male was taken" ... clinging to a paling about thirty inches from the ground, and in an apparently torpid condition" by C. G. Doughty (Doughty, 1931; Killington, 1932). The insect was identified as Myrmeleon formicarius by Claude Morley who, in an editorial footnote to Doughty (op. cit.) stated that the area had been practically unworked for over a hundred years and did not rule out the possibility of the species being native. Recent investigations by Howard Mendel at Ipswich Museum turned up Doughty's specimen in that institution (Morley Collection, number R.1953-22) and this proved to be Euroleon nostras rather than Myrmeleon formicarius. Entomologists Rec. J. Var. 125 (2013) 177 It is hard to comprehend the original misidentification of a species with darkly spotted wings with one whose wings are hyaline; the names formicarum and formicarius do not appear in the synonymy of E. nostras listed in Aspock et aI., (1980) though Mendel (1996), in considering this particular problem disagrees (but without references). Certainly, Barbut's (op. cit.) description of Myrmeleon formicarum as having wings " ... diaphanous, adorned with a network of black fibres, charged with several blackish-brown spots, rather large, especially towards their outer edge" can surely only be a description of Euroleon nostras. The dark wing markings are clearly shown in his Plates 12 and 22. The matter is further discussed by Mendel (op. cit.) who concludes that early references are best treated as unreliable and in any case should probably be referred to Euroleon nostras." Potential origins This current capture of Myrmeleon formicarius represents an addition to the British fauna. In continental Europe, M formicarius is widely distributed from Spain in the west to Turkey (and beyond) in the east and from the southern tip of Italy to the southern half of the Scandinavian Peninsula in the north (Aspock et ai, 1980 and various subsequent individual papers). It is local, but not uncommon across this entire area. However, its presence in Britain is something of a surprise. It was presumably prevented from colonisation by the last "ice age" and it is not considered to be a migratory species. It is widely established in the "cold" areas of the southern half of Norway and Sweden and also in Finland extending, in terms of latitude, to a level just north of the Shetland Islands; range expansion as a consequence of climate warming seems, therefore, an unlikely explanation. We are mindful of Morley's comments (Morley, 1932) in relation to the discovery of the (misidentified) ant-lion in Suffolk. This find was of such interest that a lengthy report appeared in a local newspaper in which Morley described the possibility of the insect having been "merely blown across the intervening seventy miles of sea" from the Continent as " ... an extremely improbable contingency". With the benefit of hindsight, and the knowledge that his specimen was in fact E. nostras, we can see that he was quite correct. That said, the likelihood of M formicarius being an overlooked resident on the Isle of Wight is very small; this specimen was surely an immigrant or a wanderer, depending upon one's personal interpretation. Unless it is breeding somewhere else on the south coast? Acknowledgements We are grateful to Paul Brock for his invaluable help.