A REVIEW OF BRITISH LEPIDOPTERA FOR 1959 b y BARON DE W O R M S AFTER a comparatively mild winter with the sallow blossom out about its normal date at the end of March, spring broke with a spell of warmth which was the prelude to one of the most remarkable summers of the Century, bringing with it continuous sunshine for prolonged periods so that a large number of species appeared often several weeks before their average date. T h i s was to be noted with the Prominents, notably the Scarce Prominent (Odontosia carmelita, Esp.), which was on the wing during the first half of April. Most members of this family quickly followed by the end of the month. T h e Small White (Pieris rapae Linn.) and the Orange-tip (Anthocharis cardamines Linn.), were well out by mid-April as also was the Speckled Wood (Pararge egeria Linn.). The almost unbroken spell of warmth continued into May with the appearance of the Alder (Apatele alni Linn.), during the second week of that month, a very early record. On May 16th the Pearl-bordered Fritillary (Clossiana cuphrosyne Linn.), was already Aying in numbers in a heat wave on the west coast of Scotland. Insects were equally forward in those northerly parts.
In spite of the hot weather very few migrants appeared during this period of the season. Only one Striped Hawk (Celerio livomica Esp.), was reported during early June. However, the indigenous species came out for the most part in abundance and many of them were virtually over at the time when one would most expect to see them. This was particularly so with the larger Fritillaries, the Silver-washed (Argynnis paphia, Linn.) and the High-brown (A. cydippe Linn.), being well out by the third week of June. So was the White Admiral (Limenitis Camilla Linn.). T h e wärmest part of the year came in the first week of July when the temperature was over 80°F. daily. T h e Chalk-Hill Blue (.Lysandra coridon Poda), was well out soon after the Start of the month and in many places was almost past its best by the beginning of August. During the third week of July several of the Small Marbled (.Eublemma parva Hübn.) were taken in Surrey and Kent. Also about this period a new British noctuid was recorded in the latter county Eriopus juventina, Cramer. T h e Purple Emperor (Apatura ms Linn.), was once more comparatively plentiful in its restricted haunts. August was on the whole a very productive month, at least three examples of the Bedstraw Hawk (Celerio galii, Rott.), were taken during the first week in the Eastern Counties and the Isle of Wight, while larvae of the Humming-bird Hawk (Macroglossa stellatarum Linn.), were quite plentiful locally on downland and
322
REVIEW OF BRITISH LEPIDOPTERA FOR
1959
sandhills, producing many imagines in September. It was this month which saw the arrival of a good many migrant species. The Clouded Yellow (Colias croceus, Fourcroy) was reasonably numerous in some parts of the south of England, notably in the south-west, particularly in Cornwall, though many were recorded in Sussex and a few in Kent, but by far the chief feature at this period of the year was the phenomenal numbers of the Red Admiral (Pyrameis atalanta Linn.). In the west of England and especially in Devon and Cornwall this insect appeared in hundreds about the middle of September, probably on a southward migration. On the other hand the Painted Lady (Pyrameis cardui Linn.), was extremely scarce, only a handful being recorded in the early autumn which saw the appearance of several interesting species. Most notable among these was a Pug new to Britain taken in Cornwall, (Eupithecia phoeniceata Rambur), an insect emanating from the Mediterranean regions. A few of the Death's Head Hawk (Acherontia atropos Linn.), were noted from such widely separated places as the Scilly Isles and the Lake District. The White Speck (Leucania unipuncta Haworth), once more appeared fairly commonly in the Scilly Isles, thus adding further evidence that it is a breeding species in that area. October saw the advent of further migrants ; during first few days a remarkable influx of the Convolvulus Hawk(HerseconvolvuliUmn.), wasobservedmainly in the Isle of Wight, in Kent and Sussex. Others were later taken in the north of England. About the same time three records were made of Blair's Mocha (Cosymbia puppillaria Hübn.), two from the outskirts of London. The Small Mottled Willow (Laphygma exigua Hobn.) was fairly numerous in the Isle of Wight, while the Scarce Bordered Straw (Heliothis armigera Hübn.) was there and in mid-Kent. Blair's Pinion (Lithophane leautieri Mabille) was once more in good numbers, penetrating to the mainland of Hampshire. A surprising capture in early October at Portland was a Flame Brocade [Trigonophora flammea Esp.), an insect common in the autumn in south-east England about a Century ago, but of which only two or three other examples have been recorded in the last 60 years. The Scarce Olive Tree Pearl {Margaronia unionalis Hübn.) again appeared in the autumn quite frequently in the south where there was an amazing abundance of the Rush Pearl (Nomophila noctuella Schiff.) which turned up at light sometimes in thousands. The Vestal (Rhodometra sacraria Linn.) was however, unusually scarce with only two or three records. 1959, in spite of the quite phenomenal spells of fine and warm weather, did not produce as much from the migrant species as might have been expected from such a remarkable summer, though members of most indigenous species were well up to average.