A Review of Lepidoptera in Britain during 1969

A REVIEW OF LEPIDOPTERA IN BRITAIN DĂœRING 1969 BARON DE W O R M S

a very mild January the whole country experienced a very severe wintry spell during most of February which was followed by a fairly bleak March. It was not tili the Easter period during the early part of April that a burst of warmth brought out the sallow bloom which was accompanied by the appearance of the first hibernating butterflies and quite a spate of moths. In the Highlands at this time the Rannoch Sprawler (Brachionycha nubeculosa Esp.) was especially plentiful as was also the Orange Underwing (Archiearis parthenias Linn.) and Rannoch Beauty (Nyssta lapponaria Boisd.). It was as early as this in the season that the first Red Admirals (Vanessa atalanta Linn.) and Painted Ladies ( V . cardui Linn.) made their appearance as a prelude to their remarkable abundance later in the season. May proved a rather fickle month with a few warm days. About the middle of the month the first rare migrants were recorded with a couple of the small noctuid, the Purple Marbled (Eublemmci ostrina HĂźbn.), seen near Winchester.

AFTER

By this time most of the spring butterflies were well on the wing, in particular quite an emergence of the Holly Blues (Celastrina argiolus Linn.), which was to prove much more numerous in its second brood in August. Also in the first part of June the Marsh Fritillary (Euphydryas aurinia Rott) was once more in very good numbers in several localities in the south of England and on the Welsh border where the Alder Kitten (Harpyia bicuspis Borkh.) reappeared, together with a great many of the Alder Moth (Apatele alni Linn.). It was during the second half of June that there began a most remarkable spell of fine and very warm weather which was to last almost throughout the whole of July, making it one of the best summer periods of the Century and bringing with it a veritable spate of butterflies which had not been observed in such plenty for a great many years.

One of the chief features of this wonderful July was the relative abundance of the Purple Emperor (Apatura iris Linn.) which was noted over a wide area in the south of England and in several spots where it had not been recorded for a great many years.

This grand insect could even be seen sailing round the treetops a dozen at a time in a few selected areas and was on the wing well into August. The White Admiral (Limenitis Camilla Linn.) also had an equally good season as also did the Swallow-tail (Papilio machaon Linn.) on the Norfolk Broads where it was in the greatest profusion throughout the summer months. The larger Fritillaries too were really plentiful, in particular the Darkgreen {Argynnis aglaia Linn.) which was even in quantity as far north as the Orkney Islands. Most of the Blues as well benefited

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by the outstanding period of sunshine with the Chalk-hill Blue (Lysandra coridon Poda) and the Adonis Blue (L. bellargus Rott.) both in the ascendancy and reappearing in some localities where they had not been observed for some time.

But it was the late summer and autumn that brought the main highlights of the year. In August there was an amazing apparent immigration of the Silver-Y (Plusia gamma Linn.) which extended to the northern isles where on the mainland of Orkney a specimen of one of the rarest species of this family, Dewick's Silver-spangle {Plusia confusa Stephens), appeared most surprisingly among a host of Silver-Ys. Only some half dozen of this species had been recorded for the British Isles since 1950 and none so far north. At this period too a number of the Small Mottled Willow (Laphygma exigua Hübn.) began to be seen andbecome increasingly numerous, probably breeding in this country. But it was only the east coast of Eire that saw a big invasion of the Hummingbird Hawkmoth (Macroglossa stellatarum Linn.) in the latter part of July, hardly any being noted on the English mainland.

After rather fickle weather towards the end of August, the Start of September brought with it a finer spell and some more rarities, notably an example of the Marbled Grey (Cryphia divisa Esp.) in East Kent, probably only the third British record. But an even greater prize appeared near Woking in Surrey during the first week of this month, the second record for Britain of the Paignton Snout (Hypena obesalis Treits.). This month too saw the capture of at least three examples of that magnificent insect the Oleander Hawkmoth (Daphnis nerii Linn.) including one from York and two from the west country where more than one Queen of Spain Fritillary (Issoria lathonia Linn.) was seen. Two other remarkable captures in these weeks was a huge Clifden Nonpareil (Catocala fraxini Linn.) as far north as the Shetland Isles with another in Suffolk.

But it was the phenomenally fine and dry October that ushered in, about the middle of the month, what would appear to have been a remarkable wave of immigrant moths and also some butterflies, for it was mainly during this period that the Clouded Yellow (Colias croceus Fourc.) came on the scene in many parts of the south of England together with a spate of Red Admirals and Painted Ladies. The moths were headed by several Death's Heads (Acherontia atropos Linn.) whereas only a very few Convolvulus Hawks (Herse convolvuli Linn.) were recorded. But the main migrants were confined to a few species. Probably the most astonishing was the appearance of several dozen of the small geometrid moth known as Blair's Mocha (Cosymbia puppillaria Hübn.). This little insect has only before occurred very sporadically in the south of England with an occasional specimen over the last twenty

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years so that its sudden increase in this region points to a definite influx from abroad. Together with this species appeared at least ten examples of the Slender Burnished Brass (Plusia orichalcea Fab.) which seems to be also increasing its ränge, as it was hardly known as a British moth before the last War. Some of this last insect may well have bred in this country, as at least one was taken in Sussex in August. Other fairly regulär migrant species were also much in evidence in these autumn weeks such as the Scarce Bordered Straw (Heliothis armigera Hübn.) and the Delicate Wainscot (Leucania vitellina Hübn.), while the White-speck Wainscot (Leucania unipuncta Haworth) found its way into Suffolk and as far north as the Inner Hebrides. One specimen of the Cosmopolitan (Leucania loreyi Dup.) was reported from Cornwall also in October. Among the geometers the little Vestal (Rhodometra sacraria Linn.) was quite numerous, while the Gern (Nycterosea obstipata Fab.) was turning up everywhere. Even the Pyrales produced at this period several rarities, including two records of the Yellow-underwinged Pearl (Uresiphita polygonalis Schiff.) and a Rambur's China Mark (Diasemia ramburialis Dup.) in Scotland. Among the more indigenous species of moths the Stout Dart (Spaelotis ravida Schiff.) was quite numerous in Suffolk in the autumn, while Blair's Pinion (Lithophane leautieri Boisd.) seemed to be steadily increasing its ränge inland in southern England as does the Black-streaked Pug (Eupithecia phoeniceata Ramb.).

So ended a really memorable and most prolific season for our lepidoptera which was a most encouraging sign when it had been feared that many well-known insects were on the decline.