Migrant insect summary – end of June 2012
Provisional weather data indicates that June 2012 was the wettest since 1860. Fortunately there was a brief respite from the unsettled conditions during the second half of the month with some hot and sunny conditions and even an arrival of Saharan dust! However it was brief and flash flooding in parts of Northern England, the Midlands, Scotland and Northern Ireland ensued. The weather over the three nights of Moth Night 2012 was particularly bad for many, with few immigrant moths reported. Observers reported very low numbers of butterflies in particular; dragonflies saw an increase in observations and moth traps finally picked up on the warm nights with many pristine and fresh individuals recorded.
Dragonfly news dominated the headlines with the dramatic discovery of a Large White-faced Darter Leucorrhinia pectoralis, also known as the Yellow-spotted Whiteface, at the National Trust’s Dunwich Heath reserve in Suffolk. The dragonfly was seen over four days (16 – 19 June) along Docwra’s Ditch – the boundary between Dunwich Heath and the adjacent Minsmere RSPB reserve; although on its final day it was not seen after 9:30am. The news was not widely disseminated due to the fear of the insect being collected, following a recent incident in Essex. Only a dozen or so lucky observers witnessed this amazing occurrence and many top dragonfly enthusiasts missed out on the 20 June when it was no-where to be seen.
Large White-faced Darter, Dunwich Heath, Suffolk - Clive Ireland
News then surfaced of one seen briefly by a single observer at Landguard, Suffolk, on 27 May. The only previous British record was way back in 1859 when one was seen on a boat off the Kent coast. Interestingly there are old claims of ‘White-faced Darters’ from the Suffolk coast which were never assigned to species. A major influx of pectoralis was evident in Northern France towards the end of May and early June and these Suffolk occurrences fit in neatly with that same movement. The likely origin for this influx is Germany or Poland.
Records of Red-veined Darter Sympetrum fonscolombii continued with widespread reports from Norfolk (Winterton North Dunes, Kelling Water Meadows, Blakeney Point and a private site) and records from two sites in Northamptonshire (Finedon Park and a private site). Single males were also observed at Hatchet Pond, Hampshire, on 20 June and Abberton Reservoir, Essex, on 24 June.
Red-veined Darter, Kelling Water Meadows, Norfolk - John Miller
Butterfly news centred on a Swallowtail Papilio machaon present for three days in Essex (27 – 29 June) along the seawall at Heybridge Gravel Pits. It was a dark individual most closely resembling the British race britannicus. Its origin is intriguing – was it a wanderer from the Norfolk broads, a release, or did it hatch locally from an imported pupa in thatch?
Swallowtail, Heybridge Gravel Pits, Essex - Adrian Kettle
The warm weather on 17 June prompted an emergence of four new butterflies on the wing for the first time in 2012 - White-letter Hairstreak Satyrium w-album in Hampshire, Black Hairstreak Satyrium pruni in Buckinghamshire, White Admiral Limenitis camilla in Sussex and Silver-washed Fritillary Argynnis paphia - also in Sussex. Twelve days later, on the penultimate day of June the Purple Emperor Apatura iris was observed in Surrey.
The immigrant moth highlight during the latter half of June was the Eastern Bordered Straw Heliothis nubigera at light at Wyke Regis on the night of 29 June (Dave Foot). This was a typical pale sandy coloured specimen, quite unlike the amazing dark one caught in Dorset in August 2006. This was the sixth Dorset record in the county which provided the first British record, way back in 1958.
Eastern Bordered Straw, Wyke Regis, Dorset - Dave Foot
On the Channel Islands a Ringed Border Stegania cararia came to light on 25 June at St. John, Jersey, (R. Long) which was an excellent record. It was first recorded on the island in 1981 and we are seeing an increase in records there, as well as on the British mainland – where the first record was as recent as 2009. Of great interest, also on Jersey, was the Dusky Clearwing Paranthrene tabaniformis pheromone-lured at Grouville Common on 28 June, after four years of trying at this site.
Scarcities included Ni Moth Trichoplusia ni at Dundry, near Bristol, Avon, on the night of 26 June. The first Scarce Bordered Straw Helicoverpa armigera of the season was at Norton-sub-Hamdon, Somerset, on 25 June. Records of Bordered Straw Heliothis peltigera came from Dorset (East Lulworth on 22nd and Portland on 27th); Sussex (Wadhurst on 20th); Kent (Dartford on 20 June and Densole on 27th) and Suffolk (Hollesley on 30th). Delicate Mythimna vitellina were light-trapped at Lizard, Cornwall and East Lulworth, Dorset, on 22 June with two further moths also in Dorset at Portland on 29th. Just a singleton of Vestal Rhodometra sacraria was recorded during this period, on the Lizard on 20 June.
Following the Striped Hawk-moths Hyles livornica recorded earlier in the season, further livornica were captured at light at Portland, Dorset on 26 June and at St. Margaret’s at Cliffe, Kent, on 30 June – the latter was the first site record. Humming-bird Hawk-moth Macroglossum stellatarum records continued to increase with widespread reports.
Humming-bird Hawk-moth, Wilmslow, Cheshire - Tony Broome
Coastal Red-necked Footman Atolmis rubricollis away from suitable breeding habitat and probable immigrants included two in Suffolk (Bawdsey on 26 June and at Hollesley the following night) and a singleton in Kent at St. Margaret’s at Cliffe on 27 June.
Red-necked Footman, Bawdsey, Suffolk - Matthew Deans
European Corn-borer Ostrinia nubilalis were reported from East Lulworth, Dorset, on 27 June and in Suffolk – at both Bawdsey and Hollesley on 26 June. The attractive pyrale Evergestis limbata was light-trapped in Hampshire, Kent and Suffolk; although some reports are likely to relate to resident individuals. A single Cydia amplana was light-trapped at Hollesley, Suffolk, on the night of 27 June.
Very low numbers of the more regular migrants Diamond-back Moth Plutella xylostella, Rusty-dot Pearl Udea ferrugalis, Rush Veneer Nomophila noctuella, Dark Sword-grass Agrotis ipsilon, Pearly Underwing Peridroma saucia and Silver Y Autographa gammal were reported.
Stop press: we have just heard the intriguing news of an Egyptian Grasshopper Anacridium aegyptium discovered on a house roof in Colyton, Devon, at the end of June - around the time of the arrival of the Saharan dust. As to its origins, who knows................