A Review of the Prevalence of British Lepidoptera in 1962

A REVIEW OF THE PREVALENCE OF BRITISH LEPIDOPTERA I N by

1962

BARON DE W O R M S

As compared with its predecessor, the chief feature of the early months of 1962 was the extreme lateness of the spring due mainly to a very bleak period during the major part of March and lasting well into April. By this time most Vegetation and insects were quite three weeks later than normal. In fact the sallow bloom was only really at its best by the middle of April at the end of which was the first appearance of the early butterflies such as the Small and Green-veined Whites (Pieris rapae, L. and P. napi, L.), but the Orange-tip (Anthocharis cardamines, L.), and the Holly Blue (Celastrina argiolus, L.), were not on the wing tili well into May. T h e first weeks of this month saw the arrival in this country of a migrant moth which was to dominate the whole season, that of the Small Mottled Willow (Laphygma exigua, Hübn.). It was reported in many places in the south of England, as many as forty in one night in one locality, in the middle of May. Supported no doubt by further immigrants among its number and also by breeding in this country this species was seen in most months right through tili the autumn, mainly in the southern half of Britain and these were probably more noted even than in 1938, the previous record for this small noctuid. This migration was soon to be followed by another of one of our more regulär visitors, the Painted Lady (Pyrameis cardui, L.), which again was prevalent throughout the summer months penetrating well in the Highlands and also breeding in the South. In the late summer it was a really common butterfly in gardens in many parts of the British Isles.

It was not tili early June that the season began to catch up, but even then it was still appreciably behind normal. Those enthusiastic collectors who visited the Highlands at this period were delighted to find larvae and pupae of the Northern Dart {Amathes alpicola, Zett.), once more in relative plenty for the first time since 1948. In the intervening years it was often difhcult to find a single example in their mountain-top habitats. T h e first half of June also saw a small immigration of the Stnped Hawkmoth (Celario livornica, Esp.), with several records from Ireland. In most places the Pearl-bordered Fritillary (Clossiana euphrosyne, L.), was only just fully on the wing by early June and as a further gauge of the lateness of the year, two rare species, the Marsh Moth (Hydrillula palustris, Hübn.), only appeared in its restricted fen haunts quite late in June, while the Alder Kitten (Harpyia biscuspis, Borkh.), was not on the wing tili early July, in both instances nearly three weeks later than the normal date.

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As might be expected, the second half of the year was distinctly richer in rare species and abundance of lepidoptera, though at no time did the daily temperature exceed 80°F. Nevertheless June ended with quite a flourish, with the addition of yet another new Pug to our list. It was discovered in the Wye Valley among the Broad-leaved Lime (Tilia platyphyllos), on which it was known to feed abroad, where it had only been recorded from a few widely separated localities. This insect (Eupithecia egenaria, Herrich Schäffer) had already found its way into our older literature under the name of the Pauper Pug, but it had always been thought that it was a case of mis-identification. Now some of the latest evidence points to the possibility that this species may yet be found in old collections and above all that it had always been a resident with us. Coupled with this discovery was yet another, that of the reappearance of the Scarce Hook-tip (Drepana harpagula, Esp.), also in the same area feeding on the Small-leaved Lime (Tilia cordata). In its only previously known haunt, the Leigh Woods near Bristol, it had not been seen for at least twenty years.

After rather a lean start several butterflies were in unusual abundance early in July somewhat locally. In particular the Dark Green Fritillary (Argynnis aglaia, L.), was in profusion on some of the southern downland areas together with the Marbled White (Melanargia galathea, L.). The middle of the month brought another sensation when five examples of the little noctuid, the Olive Crescent (Trisateles emortualis, Schiff.) were taken in the Chiltern beechwoods, just over 100 years after the last British record had been captured in the same region. Is this yet another moth that may have always been with us, but had escaped detection?

The Coming summer will doubtless throw more light on this. T h e end of July the Large Footman (Lithosis quadra, L.), appeared in unusual numbers over a wide area of the south of England with Cornwall once again the scene of its greatest plenty mainly in early August. This period also saw the capture of the second British specimen of (Euriopus juventina, Cramer) this time in East Kent, perhaps another potential coloniser.

As usual the late summer brought the chief spate of the rarer migrants. But the commoner species were singularly absent, such as the Convolvulus Hawk (Herse convolvuli, L.), and the Clouded Yellow (Colias croceus, Fourcr.), though this butterfly was in small numbers in the south-western areas in the early autumn. The two Wainscots, the White-point (Leucania albipuncta, Fabr.), and the Delicate (L. vitellina, Hübn.), were again quite numerous along the South Coast, though the latter was nothing like as plentiful as in 1961. Some butterflies were observed long after their usual final times of appearance, with the Purple Emperor (Apatura iris, L.), on the wing during the last

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days of August and the Chalk-hill Blue (Lysandra coridon, Poda), still producing fresh specimens well into October which in many ways was the best month of the year. The main emergence of the Vanessas took place then, mainly of the Small Tortoise-shell (Aglais urticae, L.), and the Peacock (Nymphalis io L.), both absentees from most buddleia bloom owing to the abnormally late season. The Adonis Blue (Lysandra bellargus, Rott.), once more had a very numerous second brood which was Aying well into the autumn.

Düring September an acute observer took some noctuid moths on the coast of Kerry which have proved to be the long lost Luperina nickerlii, Freyer) which most authorities consider to be the same insect as Guenee's Rustic (L. gueneei, Doubleday), which used to inhabit a small area of the Lancashire coast at the beginning of this Century, but has not been seen in those parts or elsewhere for some forty years. Doubtless it has always been in this region of Ireland, in a country where other new species may well remain to be discovered. This month too saw the capture of several very uncommon migrants along our southern seaboard. Among the more notable was the third British specimen of the Spanish Carpet (Ortholitha penbolata, Hübn.), from South Devon, a species fairly common in the Channel Islands. This county also provided an example of Dewick's Plusia (Plusia confusa, Stephens), which had not been seen in this country for at least five years, as well as one or two of the Scarbank Gern (Plusia limbirena, Guer.). Another of this latter migrant from the African coast of which there have only been four previous British records, was taken in the Isle of Wight together with a Slender Burnished Brass (Plusia aurifera, Hübn.), while the very rare Bloxworth Snout (Hypena obsitalis, Hübn.), was captured in the Scilly Isles. The Black-streaked Pug (Eupithecia phoeniceata, Rambur), first recorded in 1959, was taken fairly commonly in Cornwall both as the imago and as the larva which feeds all through the winter months on cypress and some kinds of juniper. The Blair's Pinion (Lithophane leautieri, Boisduval), was again quite abundant in some localities along the South Coast, but there were few records of the Vestal (Rhodometra sacraria, L.) or of the Scarce Olive-tree Pearl (Palpita unionalis, Hübn.). T h e autumn months proved very prolific for the general run of both butterflies and moths and a welcome final visitor was a Silver-striped Hawk (Hippotion celerio, L.), found sitting on a vine in East Kent in November. So ended an interesting, though not very spectacular year, either for abundance of insects generally or for profusion of migrant species.