Atropos migrant insect summary – late May 2012

The first five months of 2012 have been somewhat disappointing for Odonata and Lepidoptera enthusiasts alike; especially when compared to 2011 with the Vagrant Emperor Anax ephippiger influx and exciting moth immigration of late April and early May.

January began unsettled although quite mild with below average rainfall. This continued into early February until the 4th when snow fell across much of the country. Freezing conditions persisted for ten days with some severe overnight frosts. In contrast, the latter half of February was quite mild, with 19 degrees recorded in Warwickshire on 23rd. High pressure dominated in March, producing summer-like weather for many, with temperatures even reaching a record 23 degrees in Moray and Aberdeenshire over 26 – 28 March. March was incredibly dry with hosepipe bans announced for many in Eastern England. Hopes of a warm dry spring were however dashed with the arrival of April! April was the wettest on record with very unsettled and unseasonably cool conditions throughout. The first half of May continued unsettled in the same vein as April; with northerly winds even bringing snow to higher ground. In contrast, the second half of May was been getting progressively warmer, with temperatures as high as 28 degrees recorded in Kinlochewe in the Scottish Highlands and Bournemouth, Dorset, on 26th. We can only hope that our insect fauna has not been too adversely affected by the very dry conditions followed by the incessant rain.

Migrant Odonata were non-existent during the period to late May. Resident species did however include sightings of traditionally the earliest species to emerge - Large Red Damselfly Pyrrhosoma nymphula during March from Cornwall, Pembrokeshire, Dorset and Hampshire. Hairy Dragonfly Brachytron pratense was seen in Somerset on 13 April; Broad-bodied Chaser Libellula depressa in Devon on 20 April and a fresh exuvia of Downy Emerald Cordulia aenea found in Wiltshire on the final day of April. Mid-May saw Common Clubtail Gomphus vulgatissimus emerging at their classic site on the Thames at Goring, Berkshire, from 12th. The second half of May produced records of Emperor Dragonfly Anax imperator from Cornwall on 19th; with both Brilliant Emerald Somatochlora metallica and Scarce Chaser Libellula fulva on the wing in West Sussex on 21st. The last few days of May have provided sightings of White-faced Darter Leucorrhinia dubia from Ross and Cromarty and Staffordshire.

Butterfly migration news this spring has mainly centred around sightings of the Large Tortoiseshell Nymphalis polychloros. Sightings came from Lydd-on-sea, Kent, on 15 March; Walter’s Copse, Isle of Wight, from 27 March to 2 April (one possibly two individuals); Warblington, Hampshire, on 30 March; Longstone, St. Mary’s, Isles of Scilly, on 10 March and at Porth Hellick (also St. Mary’s) on 1 April. Camberwell Beauty Aglais antiopa were seen at Marley Common, West Sussex, on 22 March and Winterbourne Dauntsey, Wiltshire, on 25 March. A few Clouded Yellow Colias croceus sightings so far this year included an early one at Paignton, Devon, on 19 March with further sightings in Glamorgan, Dorset and Warwickshire up to 12 April. The Warwickshire record on 23 March was the earliest ever in that county by a month. Small numbers of Painted Lady Vanessa cardui were reported with sightings from Norfolk on 8 January, Greater London on 28 March and Derbyshire on 2 April. Likewise Red Admiral Vanessa atalanta sightings were sparse but did include an overwintering one in Sussex on 1 January.

Many resident butterflies emerged early during the warm spell in March/early April including Grizzled Skipper Pyrgus malvae in Sussex on 24 March with Green Hairstreak Callophrys rubi in Cambridgeshire on the same day; Pearl Bordered Fritillary Boloria euphrosyne in Devon on 1 April and Duke of Burgundy Hamearis lucina in Gloucestershire on 6 April. More recently Glanville Fritillary Melitaea cinxia was on flying on the Isle of Wight on 11 May and Chequered Skipper Carterocephalus palaemon in Argyll on 15 May.

The mothing year started with the appearance of more examples of Black-spotted Chestnut Conistra rubiginosa in North Kent. At Longfield, eight miles southeast of Dartford, where the species was first recorded in November 2011, singles were light-trapped on the nights of 23 and 29 February. This species certainly seems to have colonized this area and will no doubt spread in due course becoming a familiar late autumn/early winter sighting. The similar Red-headed Chestnut Conistra erythrocephala was recorded from Harewood Forest, Hampshire, on 17 February; Wadhurst, East Sussex, on 23 February and 29 March; Ruckinge, Kent, on 22 March and Hollesley, Suffolk (two in late February).

The glorious early spring weather in March raised hopes of moth immigration. A small arrival of moths did include a sprinkling of Diamond-back Moth Plutella xylostella, Rusty-dot Pearl Udea ferrugalis, Rush Veneer Nomophila noctuella, Humming-bird Hawk-moth Macroglossum stellatarum, Dark Sword-grass Agrotis ipsilon and Silver Y Autographa gamma. Scarcer immigrants during this period included Pearly Underwing Peridroma saucia (three at Portland, Dorset, during 17 – 23 March), Ballycotton, Co. Cork, on 27 March (with another a month later on St. Mary’s, Scilly on 27 April); White-speck Mythimna unipuncta at Tighnabruaich, Argyll, on 13 March (with another at Bonchurch, Isle of Wight a week later) and a couple of presumed immigrant Blossom Underwing Orthosia miniosa appeared in Dorset (at West Bexington and Broadwey) in early April.

The unsettled weather during the first half of May has been very unproductive for immigrant moths but there were some highlights; single Striped Hawk-moth Hyles livornica were light-trapped at Orpington, Kent, on 1 May and at Lydd-on-sea, Kent, on 8 May; a Vestal Rhodometra sacraria by day at Wickham Common, Hampshire, on 3 May and single Gem Orthonama obstipata at Lizard, Cornwall, on 2 May and St. Osyth, Essex, on 4 May.

The appearance of Dewick’s Plusia Macdunnoughia confusa at Dartford, Kent, on 10 May was interesting. Was it a resident (like the Black-spotted Chestnut) or a primary immigrant – a superb record nonetheless!

As this article was going to press we have heard the exciting news of Cloaked Pug Eupithecia abietaria at Coventry, Warwickshire, on the night of 25 May (C. Potter) and of a Lunar Double-stripe Minucia lunaris trapped at St. Margaret’s at Cliffe, Kent, on the night of 26 May (T. Morris). Hopefully this is a sign of better things to come…. As always we would like to thank you for your contributions to Atropos and look forward to an exciting summer ahead.