British Macro-Lepidoptera, 1955

A REVIEW OF BRITISH MACRO-LEPIDOPTERA FOR 1955

By BARON DE WORMS, M . A . , PH.D., F . L . S . , F . R . E . S .

The year opened with a very prolonged winter and it was not tili well into the middle of March that any of the hibernated butterflies appeared, while the sallows were not in fĂźll bloom tili the second week in April. Thus the whole Start of the season was very late. Both the Northern Drab (Ortliosia advena Schiff.) and the Scarce Prominent (Odontosia carmelita Esp.), were quite numerous at the beginning of May, which was for the most part a very bleak month. It was only at Whitsun during the last week of the month that the Pcarl-bordered Fritillary (Clossiana euphrosyne Linn.) was at its height. It was at this period that a single example of the Striped Hawk (Celerio livornica Esp.) was taken in the New Forest. The early part of June was again very wet and somewhat unproductive. Only during the second half can the season be said to have begun in earnest. Some exceptionally warm weather started about this date and was the chief feature almost throughout the rest of the summer. During the third week of June the Alder Kitten (Cerura bicuspis Borkh.) and the Alder Moth (Apatele alni Linn.) were fairly plentiful in some of the southern and midland counties. The nights were extremely warm and produced some phenomenal catches of moths. It was at about this time that a most outstanding discovery was made in the form of an entirely new geometer moth for the British Isles.

It has been named the Balsam Carpet after its foodplant Impatiens fulva, which grows along many streams in the southern counties.

Its scientific name is Xanthorhoe biriviata Borkh. = pomoeriaria Eversmann. It was caught in some numbers in June and bred through to a second generation in the late summer.

The general weather throughout July was some of the finest experienced for many years. The continuous warmth was responsible for an amazing abundance of lepidoptera. The Purple Emperor (.Apatura iris Linn.) was commoner than it has been for many years, being seen in many places Over a wide area in the south and often more numerous than the White Admiral (Limenitis Camilla Lin.). During the latter part of July began some remarkable migrations, the most outstanding of which was the appearance of the Bedstraw hawk-moth (Celerio galii Rott.) which was in some ways the highlight of the year. During these weeks well over fifty of this fine moth were recorded over the whole of the south of England ranging to the Lake District and to Dublin.

Many series were bred and in the later summer a good many larvae were found over a large area, mainly feeding on willowherb.

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Two species chiefly associated with our northern counties also appeared as migrants. These were the Great Brocade (Eurois occulta Linn.) which turned up in numbers in many of the southern counties with the largest proportion in Essex, but still more surprising at the end of July was the capture of several of the Scarce Silver Y (Plusia interrogationis Linn.) in Essex and Kent.

There have been very few records of this insect in the south and the form obtained was quite unlike those norraally taken on the moors of Yorkshire or the Highlands. Several indigenous moths of somewhat local occurrence were in unusual plenty at this season. These included the Triple-spot Clay (Amathes ditrapezium Borkh.) and the Slender Brindle (Apamea scolopacina Esp.). They were met with in many places where they had not been previously recorded.

August turned out to be a month of almost continuous sunshine over the whole country with the result that the lepidoptera were in great profusion. This particularly applied to the Chalkhill Blue (Ly sandra coridon Pod.) which was in thousands in many of its regul채r haunts, though it did not produce much Variation.

Scotland shared the great warmth at this period and most species abounded in that region. Of special note there was the Piain Clay (Amathes depuncta Linn.), the Heath Rustic (Amathes agathina Dup.), the Coast Dart (Euxoa cursoria Hufn.), the Deepbrown Dart (Aporophyla lutulenta Borkh.) and Haworth's Minor (Celaena haworthii Curt.). This month too saw an amazing immigration of White Butterflies, chiefly the Small White (Pieris rapae Linn.) which swarmed over the south coast. The Clouded Yellow (Colias croceus Fourc.) was also fairly plentiful in the late summer producing further progeny in the autumn, but very few of the Pale Clouded Yellow (Colias hyale Linn.) were recorded.

Other migrants of special note at this period were the Vestal {Rhodometra sacraria Linn.) which usually benefits with a dry summer. It appeared in many parts of the south, while that most attractive white Pyrale, the Olive-tree Pearl (Margaronia unionalis H체bn.) had probably a record season, continuing well into the autumn. T h e late summer too was also notable for the capture of several insects of exceptional rarity. These were a specimen of the Three-humped Prominent (Notodonta phoebe Sieb.) from Folkestone, only the third for the British Isles this Century, while Southsea produced the second British example of the Dark Marbled Beauty (Cryphia raptricula H체bn.).

August also saw the capture of a further specimen each of the Eastern Blackneck (Tathorhynchus exsiccata Led.) near Arundel and of Blair's Mocha (Cosymbia puppillaria H체bn.) at Otford, Kent, in each case the fourth record for this Country, while a male of the Gipsy moth (Lymantria dispar Linn.) was taken at light in Gosport. Among the butterflies an extraordinary capture

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A REVIEW OF BRITISH

MACRO-LEPIDOPTERA

was a female Apollo (Parnassius apollo Linn.) in the Warren at Folkestone where a Camberwell Beauty (Nymphalis antiopa Linn.) was caught on buddleia in the town. But on the whole the Vanessids were not in especial quantity tn spite of the hot season, though the Red Admiral (Pyrameis atalanta Linn.) was very plentiful and there was sprinkling of the Painted Lady (P. cardui Linn.).

September was another good month, but it did not produce any abnormal migration as it is wont. Only a very few ConvolVulus Hawks (Herse convolvuli Linn.) were reported. The feature of this period was the Plusias. T h e Gold-spot (Plusia festucae Linn.) was abundant almost everywhere, while four more examples of the Silver-spangle (Plusia confusa Steph.) were taken in Kent, Surrey and Norfolk, thus giving evidence that it is slowly establishing itself over here. Another most notable capture was the Golden Twin-spot "(Plusia chalcites Esp.) in South Devon, only the second authentic British example of this sub-tropical and cosmopolitan species. The discovery of the foodplant of the Giant Ear (Hydraecia hucherardi Mab.) attracted a largenumberof collectors to the Romney Marsh area in September.

The moth was found quite plentiful at rest or Aying round the Marsh Mallow (Althaea officinalis). Good series were also bred from larvae dug from the roots in July. Several new residents appeared to be increasing their ränge such as the Toadflax Brocade (Calophasia lunula Hufn.) and the Varied Coronet (Hadena compta Fab.) now quite common in the Eastern Counties. Four further examples of Blair's Pinion (Lithophane lapidea Hßbn.) were obtained in early October in Sussex and the Isle of Wight, showing that it must be breeding in this country.

The autumn provided quite a lot of insects, the Plumed Prominent (Ptilophora plumigera Esp.) being numerous in early November.

It was in the first week of this month that probably the most startling captures of the year were made, that of two Plusia acuta Walker, known as the Tunbridge Wells Gern from the original and only other British specimen taken there in 1870.

Both insects were caught at m /v light on the night of the 5th, at Woking and near Newbury, thus pointing to a probable migration from tropical Africa, the only known habitat of this species which has never been recorded from the mainland of Europe.

The only other late autumn record was a Cosmopolitan Wainscot (Leucania loreyi Dup.) taken near Alton in Hampshire in October.

It has never been taken so far inland before.

Thus ended a most memorable season. 1955 can certainly be counted among the best years for collecting and for abundance of insects during the present Century.

Three Oaks, Shore's Road, Woking, March, 1956.