A Review of Lepidoptera in Britain during 1967

A REVIEW OF LEPIDOPTERA I N BRITAIN DÜRING 1967 BARON DE W O R M S

THE early weeks of 1967 were for the most part very mild with very little sign of winter. Most of the new year's species of moths were out well before their normal date. But it was in the opening days of February that there took place some most spectacular captures to open the new season. No less than three examples of the Eastern Blackneck (Tathorrhyncus exsiccata, Lederer) were taken at light near Winchester in exceptionally warm conditions for the time of year. There had been only four previous records of this migrant to British shores during the 1950's. These unexpected visitors were accompanied by a specimen of yet another extremely rare pyrale, the Necklace Grass Veneer (Euchromius ocellea, Haworth) as well as by several of the common migrant pyrale, the Rush Pearl (Nomophila noctuella, Schiff.).

Evidently there had been a very substantial immigration from the Continent, but it was curious that no other examples of these scarce vagrants were recorded at this very early period. T h e mild spell continued throughout March which was a very congenial month with the sallows in füll bloom in its first half and some of the first spring butterflies appearing by the end of it. T h e Notodonts began emerging by the second week in April, notably the Scarce Prominent (Odontosia carmelita, Esp.), while hibernated examples of the Dotted Chestnut (Dasycampa rubiginea, Fab.) were more numerous than usual in their heathy habitats.

But after this very promising and precocious Start the season experienced a big set-back during May when a very cold and bleak spell prevailed for nearly the whole month, at the end of which most species were well behind schedule. T h e smaller Fritillaries only began appearing during the second half of May when the Larger Pearl-bordered (Clossiana euphrosyne, Linn.) proved to be fairly common in the south-east of England. But virtually no migrants of note were recorded during this late spring. However, June boded better with much warmer weather throughout the month.

In fact towards the middle of June the thermometer reached the upper 70's almost daily for a week which brought on the tardier insects at füll speed. It was a good year for our smallest butterfly, the Small Blue (Cupido mimimus, Fuessl.) which was about in unusual numbers, especially in the Chilterns. Fine conditions prevailed almost for the whole of June. In fact it was the prelude to a really remarkable summer. For the warmth continued into July which was one of the finest on record with a real heat wave during its second week. It was during this period that the Olive Crescent (Trisiteles emortualis, Treits.) which had been virtually absent in 1966, suddenly appeared in amazing abundance in its very restricted Chiltern haunts.

No less than seventy imagines were seen at light and at rest in the beech woods during

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the middle week of July. Ova were obtained and a few larvae were bred up, but many more of these were found wild during the autumn feeding on dead leaves as is the wont of this group of the Snout moths. This is the first time that the earlier stages of this Strange little insect have been worked out in this Country where the species was hardly known to occur until 1962. Another most interesting record and capture during the first half of this month was the second British example of the Dusky Fanfoot (Zanclognatha tarsicrinalis, Knoch.). Like the original example obtained in Suffolk in 1965, this specimen was also taken in that County, thus bringing evidence that it may well be established there as a resident and quite probably overlooked through its similarity to nearly-related species.

The latter half of July was equally propitious with once more a spate of the Dark Green Fritillary (Argynnis aglaia, Linn.) in parts of Wiltshire with a very good showing of the Marbled White (Melanargia galatea, Linn.). The Purple Emperor (Apatura iris, Linn.) too had quite a good season, being seen in nearly all its Standard localities in the second part of July. The Chalk-hill Blue (Lysandra coridon, Poda) began to emerge during the last days of the month and proved to be exceptionally plentiful in some of its remaining downland haunts. Doubtless the continuous fine spell enhanced the good emergence.

However, this remarkably fine weather was bound to end after nearly two months and the opening days of August were far from congenial. It was during the first week of this month that there took place a most astonishing discovery. In 1965 a single specimen of the Rosy Marsh Moth (Coenophila subrosea, Stephens) was taken in the northern half of Wales. Until then no example had been seen in Great Britain since about 1850. This startling capture gave rise to the belief that this long lost species might still lurk as a resident. Amazing to relate this proved to be true, since this attractive noctuid moth proved abundant at mercury-vapour light in a marshy area some fifty miles from where the 1965 capture was made.

It is an insect of an almost unlimited variety of shades of pink and red tints and also of markings so that hardly two examples can be exactly matched. It seemed extraordinary that this fairly large moth has remained undetected in these numbers for all this time which gives rise to the idea that several more of our supposedly extinct species may still exist in this way unknown in some of the more remote regions of our Islands. It is hoped to work out the life hi story of the Rosy Marsh Moth during the season of 1968.

Another Suffolk record of especial interest at this period was that of the pyrale, the Marsh Pearl (Perinephele perlucidalis, HĂźbn.) which had not been taken so far east before and had only been added to the British list fairly recently. The late summer saw a very good emergence of the Holly Blue (Celastrina argiolns, Linn.) which had been absent for several years. However, some very

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Transactions of the Suffolk Naturalists',

Vol. 14, Part 2

sunny days ushered in September which also brought out a large emergence of the small Tortoiseshell (Aglais urticae, Linn.), especially on some of the Dorset downs which also produced a very good showing of the second brood of the Adonis Blue (Lysandra bellargus, Rott.). There was quite a number of records of the Death's Head Hawkmoth (Acherontia atropos, Linn.) during this month, while the Convolvulus Hawk (Herse convolvuli, Linn.) was extremely scarce. As usual at this time of the year a certain number of other migrants reached our shores, including a fair number of the Delicate Wainscot (Leucania vitellina, H端bn.) and of the Small Mottled Willow (Laphygma exigua, H端bn.) together with a few of the Vestal (Rhodometra sacraria, Linn.). But there was a marked absence of the Painted Lady (Pyrameis cardui, Linn.) and of the Red Admiral (P. atalanta, Linn.) often so plentiful at this time of year as in 1966. It was a good season for some of the later noctuid moths such as the Heath Rustic (Amathes agathina, Dup.) and for the Small Square-spot (Diarsia rubi, View.) which was in vast numbers for its summer emergence. T h e Blackstreaked Pug (Eupithecia phoeniceata, Ramb.), first recorded in Britain in 1959, was especially plentiful in South Devon and other regions in that vicinity. But a most unexpected visitor, apparently new to the British list, appeared in a moth trap near the north of London, at Totteridge, in the form of a rather dark-looking noctuid which has been identified as Caradrina flavirena, H端bn., a Mediterranean insect which has similarities to the Pale Mottled Willow (Caradrina clavipalpis, Scop.) with which it may have been confused, though this apparent arrival from foreign parts is most likely to have been a genuine migrant. Another rare visitor in the autumn was the fifth British record of the Tunbridge Wells Gern (Plusia acuta, Walker), taken in the West Country.

This species of African origin has apparently not yet been caught on the mainland of Europe. Quite a sensation was caused when the eminent Swedish entomologist, Dr. Svensson, announced that our common Copper Underwing (Amphipyra pyramidea, Linn.) did in fact embrace another species readily separable on genitalia structure and other superficial features rather on the analogy of the two Gold-spots (Plusia festucae, Linn, and P. gracilis, Lempke). The newly-separated insect, named Amphipyra berbera, Rungs, seems almost as prevalent as A. pyramidea.

Its general appearance is somewhat more drab and there is a less lustrous sheen on the wings than in the original Copper Underwing, while the central mark on the forewings is always oval whereas it is usually smaller and quite circular in A. pyramidea.

As usual at the latter part of the year there were some pyralids of immigrant origin. Of these there were several records of the Scarce Olive-tree Pearl (Palpita unionalis, H端bn.), at least two of the Yellow-underwinged Pearl (Uresiphita polygotialis, Schiff.),

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both from Hampshire, and one of Rambur's China-mark (Diasemia ramburialis, Scop.) in Suffolk. A very interesting addition to the British list among this family was a Single example of the very small species Hellula undalis, Fab. It was only towards the end of the autumn that there was quite a spate of nightflying species. The Plumed Prominent (Ptilophora plumigera, Esp), was fairly numerous, especially in its newly-discovered haunts in Sussex, while large numbers of the December Moth (Poecilocampa pupuli, Linn.) were reported at light within a few days of Christmas together with the winter geometers the Golden Umber (Erannis aurantiaria, Esp.) and the Mottled Umber (E. defoliaria, Clerck).

In spite of the very fine summer period, especially during June and throughout July, there was not the spate of insects that might have been expected either among the day-flying residents species or for the most part of the regulär migrants, though at one period, mainly during the second part of August, there were quite phenomenal numbers of the commoner moths Coming to mercury-vapour light traps.