The second half of November remained rather mild and quite dry but the southerly winds were often too strong to help trapping efforts. December was very unsettled, with severe gales, hail, rain, snow and ice, giving Britain its first taste of true winter. Initially migrants continued to drift in, mainly along the south coast, but a sharp double-night frost around 1st December brought this year's moth-ing season to a sudden close. The influx of Red-headed Chestnuts continued with three more at Bonchurch (Isle of Wight) between 16th and 19th November. Elsewhere there were two in Suffolk and singles in Cornwall, Dorset, Essex and Norfolk by the 25th.
Red-headed Chestnut at Bonchurch (Isle of Wight) — one of three at this site in November (James Halsey).
Despite raised awareness, there were no more reports of Black-spotted Chestnut, making the events of early November in Dartford (Kent) even more amazing! A late Golden Twin-spot was found in the Norfolk Broads on 19th November. A Silver-striped Hawkmoth was on The Lizard (Cornwall) on 20th with a Scarce Bordered Straw and three Cosmopolitan at the same location around this time. A White Point was at Pegwell Bay (Kent) on 22nd on the same night as the last two reported Large Wainscots, which nationally have had a bumper autumn, no doubt involving many migrants.
Large Wainscot at Gretton (Glos) (Roger Wasley).
Four Hummingbird Hawkmoths included a December record to light in Coventry (Warks) on 1st. Two White-specks were in Cornwall at the end of November. A Death's Head Hawkmoth was sadly found dead, in good condition, on a garden lawn at East Dean (East Sussex) on 12th December. Seven Vestals and 24 Gems concluded an excellent autumn showing for these attractive geomotrids.
Male Gem at Woodnewton (Northants) (Nick Smith).
Other macro migrants included 14 Turnip Moth, 36 Dark Sword-grass, eight Pearly Underwing, a few Angle Shades, four Vine's Rustic and 144 Silver Y. Of the pyralids; eight Palpita vitrealis and 16 Rush Veneers, and no fewer than 359 Rusty-dot Pearls were recorded. Twenty-five Diamond-back Moths were also logged.
Female Palpita vitrealis from the underside, showing brush-like appendages responsible for active dispersal of pheromones, used to attract males. (James Halsey).
Rusty-dot Pearl — the most abundant migrant of the autumn (Steve Whitehouse).
Dark Arches were recorded from a dozen sites and the last Large Nutmeg was at Woodnewton (Northants) on 26th November. Two Double-striped Pugs trapped in Dorset in late November were not that exceptional but a Common Pug at Balsall Heath (Warks) on 19th November and a Sharp-angled Peacock on The Lizard (Cornwall) the next day certainly were.
Single Oak Rustics at Funtley and South Hayling (both Hampshire) in late November were welcome records away from the main Dorset colony. After several records at Weymouth (Dorset) and in East Devon in 2009, moth-ers were all geared up for a further wide-scale westward colonisation of the species, a decade on from its first appearance in Britain in 1999. However, after two very cold winters it seems the species may have been pegged back to its original footholds at a handful of south-coast breeding sites, as there have been no more records west of the Purbeck peninsula in the last two years.
Oak Rustics of the nominate 'orange-marked' and albomacula 'white-marked' forms at Durlston (Dorset) (Phyl England).
Carrying on from last month's very early emergence dates, a single Spring Usher was out at Wadhurst (East Sussex) on 22nd November. Pale Brindled Beauty were found at Andover Down (Hants) on 19th November and at Alderholt (Dorset) on 21st, and later in Lancashire on 2nd December and at East Lulworth (Dorset) on 8th. Very early Dotted Borders were reported in Somerset at Wiveliscombe on 2nd December and at East Lydford the following night.
Pale Brindled Beauty — this late-winter species is rarely seen before Christmas (RSPB).
At least five more Common Quakers and seven Hebrew Characters were recorded, the latter including three at Tynemouth (Northumberland) by 2nd December.
The previously mentioned possible Eastern Nycteoline, caught at Dungeness Bird Observatory (Kent) on 30th September, was subsequently examined in detail at the British Museum and found to be a female Oak Nycteoline. This now throws into doubt whether or not the continental species can be identified visually, even when it appears to match images of presumed Eastern on the web. Also in Kent, earlier in the summer, Bernard Boothroyd caught an unknown reddish noctuid near Hamstreet on 18th July. The adult moth was not retained but the photo below clearly shows a puzzling individual. Opinions from the photograph range from a very aberrant Uncertain to yet another variety of Ingrailed Clay. Please feel free to comment if you think you know what it may be!
Unknown noctuid moth at Ruckinge (Kent), July 2011 (Bernard Boothroyd).
Keen Dorset moth-ers Dave Foot and Phil Sterling have been kept busy nurturing tropical moths, which arrived during the large-scale October influx. A female Crimson Speckled from West Bexington was mated with a male caught at nearby Frampton and eventually she laid eggs. These were kept indoors in a specially heated propagator and very soon had hatched into tiny larva. Fed on garden forget-me-nots, they matured very quickly through various larval stages, pupating in late November. The first of the new-generation adults emerged on 9th December and made history in becoming the first ever reared from a wild female's eggs.
Final-instar larva of Crimson Speckled at Weymouth (Dorset), November 2011 (Dave Foot).
Second-generation adult Crimson Speckled at Weymouth (Dorset), December 201 (Roger Wasley).
A gravid female Old World Webworm, also from West Bexington, laid about 50 fertile eggs that quickly hatched into larvae. Reared on small cabbage plants, these pupated even faster than the Crimson Speckled and started emerging near the end of November.
Second-generation adult Old World Webworm at Weymouth (Dorset), December 2011 (Roger Wasley).
Many recorders had ample chance in the mild late-November period to attract two species to garden traps that typify the approaching end of season. Many were rewarded with the Sprawler which, as you can see below, is well named scientifically as Asteroscopus sphinx.
Sprawler (Roger Wasley).
Some late-season field moth-ers had very high counts of December Moth, especially in ancient woodland where as many as 50 per site were counted. It is normally one of the last macro moths of the year to emerge and once seen, for many, marks the time to put away the traps.
December Moth (Roger Wasley).
A handful of migrant Painted Lady butterflies lingered in late November and a few Red Admirals were still being reported on the wing in gardens in early December. What may well be the last Vagrant Emperor dragonfly of 2011 was sadly found moribund on a Coventry pavement on 25th November.
Waring, Townsend and Lewington. Field Guide to the Moths of Great Britain and Ireland. Revised edition, British Wildlife Publishing, 2009.
UKMoths online photographic guide