A review of Lepidoptera in Britain during 1974

A REVIEW OF LEPIDOPTERA IN BRITAIN DÜRING 1974 BARON DE W O R M S

O N C E again very mild conditions ushered in the first weeks of this year with the temperature above 50°F for most days throughout January and February alike which caused a fairly early emergence of insects. The common Orthosias were well on the wing by the latter half of February, particularly the Common Quaker (Orthosia stabilis Schiff.), while the Yellow-horned (Achlya flavicornis Linn.) followed suit by the last week of the month. However a real touch of winter came in the first half of March with heavy snow on the lOth in southern England. This cold snap put the season back to about its normal sequence. By the last week of this month much warmer conditions prevailed again with the sallows in füll bloom. T h e thermometer topped 60°F on the 25th March bringing out plenty of hibernating butterflies, especially the Brimstones (Gonepteryx rhamni Linn.) and the Small Tortoiseshell (Aglais urticae Linn.). April opened with some very warm weather with congenial spells throughout most of the month bringing forth the early Whites and the Orange-tip (Anthocharis cardamines Linn.) well before the end of April. May, however, started very coolly with a good deal of rain, but the middle of May saw a short-lived heat-wave with the thermometer over 70°F for at least a week. This spell brought out quite a burst of butterflies. On the 19th the Wood White (Leptidea sinapis Linn.) was in exceptional numbers on the Surrey-Sussex border which was a delightful sight. The Pearl-bordered Fritillary (Clossiana euphrosyne Linn.) was also well out in this area by this date. Another butterfly which was in plenty at this period on the downs was the Small Blue (Cupido minimus Fuessl.). Quite a number of moths were enticed out earlier than usual by this warmth with the Pine Hawk (Hyloicus pinastri Linn.), the Figure-of-Eighty (Tethea ocularis Linn.) the Alder Moth (Apatele alni Linn.) and the Sycamore Moth (Apatele aceris Linn.) all appearing about 20th May. The warm weather carried on tili the Start of June when on the first it was most gratifying to see the Adonis Blue (Lysandra bellargus Rott.) in fair quantity on some of the Surrey downs, since this butterfly seems to have been declining steadily in many of its localities. Summery conditions were maintained during most of the first half of June which saw the Wood White still Aying in some numbers. During the second half of the month the weather was much more mixed. However there was quite a flood of nocturnal insects, especially in the West Country, though virtually none of the less common migrant species put in appearance. There was quite an incursion of the Silver-Y (Plusia gamma Linn.) for a few days on the Lizard Peninsula which also produced quite a lot of Barrett's Marbled

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Coronet (Hadena barrettii Doubleday). That part of England saw at this period a great emergence of the Red-necked Footman (Atolmis rubricollis Linn.) which were in great plenty in woodlands in parts of Cornwall, even along its coast and in the Scilly Islands where larvae were abundant in the autumn. But the expected reappearance of the Bedstraw Hawk (Hyles gallii Rott.) after its great invasion in 1973, did not materialise in 1974 to any extent. Only a handful of this Hawkmoth were reported, two in Shetland, and few larvae apparently so that this fine insect seldom seems to survive our fickle winter climate. Very few Death's Head Hawks (Acherontia atropos Linn.) were likewise recorded during the late spring from any part of the country.

One of the few butterflies that had a good season was the Heath Fritillary (Mellicta athalia Rott.), especially in its western haunts where it was well out during the first half of June. The Silverstudded Blue (Plebeius argus Linn.) was well on the wing on the heaths in Surrey and Hampshire by the end of June.

There seemed to be a distinct leanness in the numbers of most of the summer butterflies during the beginning of the second half of the year, though the July weather was on the whole fairly congenial. The larger Fritillaries, particularly the Silverwashed (Argynnis paphia Linn.) had a poor showing in most of its usual haunts as also did the White Admiral (Limenitis Camilla Linn.) and even the Purple Emperor (Apatura iris Linn.) was well below its normal strength. However the Blues fared better and one butterfly which showed remarkable abundance from the middle of July was the Chalkhill Blue (Lysandra coridon Poda).

In some of its localities, especially along the south coast it was in prodigious numbers with dozens of both sexes Aying up at almost every step. This indeed was a most encouraging phenomenon after the current talk of the gradual disappearances of many of our butterflies owing to pesticides and destruction of habitats.

During the last days of July a great rarity turned up at Dungeness in Kent in the form of a specimen of the Scarce Chocolatetip (Clostera anachoreta Schiff.) of which possibly not more than half a dozen examples have been recorded in the past fifty years, though at the end of the last Century this species was found as larvae in numbers in Kent and Sussex and bred on a large scale.

The last specimen of this insect to be obtained in this rieh locality was in 1953 so that it may still be breeding unnoticed there. A single male was taken at Waldringfield in 1956 on the Suffolk coast.

In spite of reasonably warm weather during most of August the usual Vanessid butterflies which so freely visit buddleias in gardens, were very scarce. Hardly any Peacocks or Small Tortoiseshells were seen in the late summer over most of the south-eastern parts of England, while the Red Admiral (Nymphalis atalanta Linn.) was almost non-existent in these regions, though

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slightly more numerous in the extreme south-west. There were very few reports of the Painted Lady (Vanessa cardui Linn.) and possibly none of the Clouded Yellow (Colias croceus Poda). Düring August a single Striped Hawk (Celerio livornica Esp.) came to a light-trap at Great Bealings in Suffolk, apparently the only record of this well-known migrant for 1974.

Düring this period of the summer a few small moths were noted in exceptional abundance in most of southern England.

These were the second brood of the Oak Hooktip (Drepana binaria Hufn.), the Marbled Beauty (Cryphia perla Schiff.) and Vine's Rustic (Caradrina ambigua Schiff.). The first days of September saw a remarkable spate of the Large Footman (Lithosia quadra Linn.) mainly on the Lizard Peninsula in Cornwall where the Marbled Green (Cryphia muralis Forst.) was also in great plenty in its many forms. Apart from these local outbursts of lepidoptera most species suffered very considerably in the very wet and bleak periods which were prevalent throughout September and October, making the autumn one of the leanest for them probably since the last war.

However there were a few bright spots in these sombre weeks as in mid-September three remarkable captures were made in the London area. First was a Camberwell Beauty (Nymphalis antiopa Linn.) caught near Forest Hill. Next was that of an African (Lycaenid) Blue butterfly, known there as the Brown Playboy (Deudorix antalus Hoppfer), caught in a garden at Twickenham. Its occurrence there is, of course, problematical, but it is quite likely that its chrysalis was imported in produce from the tropical regions it inhabits. The other startling capture, at Eltham, was a male of that famous migrant butterfly, the Monarch (Danaus plexippus Linn.), also seen Aying in a local garden. The middle of September too saw quite an immigration into the Scilly Isles of a number of the Convolvulus Hawk (Herse convolvuli Linn.) as well as several of the White-speck Wainscot (Leucania unipuncta Haworth) and of the Delicate (Leucania vitellina Hübn.), one of which penetrated as far inland as Surrey.

Düring October there were records of Blair's Pinion (Lithophane leautieri Boisd.) being taken also well inland in the London Area.

This autumn insect seems to be steadily expanding its ränge from the south coast. The last fortnight of 1974 was extremely mild producing some of the early geometers such as the Pale Brindled Beauty (Phigalia pedaria Fab.), the Spring Usher (Erannis leucophaearia Schiff.), and the Early Moth (Theria rupicapraria Schiff.) over the Christmas period, an extraordinary phenomenon.

Düring 1974 it became known that a specimen of the Dusky Peacock moth (Semiothisa signaria Hübn.), a small geometer with pine as its pabulum, had been taken in Essex in the summer of 1970, but it had not been fully recognised tili fairly recently.

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To summarize, the year 1974 is generally regarded as a very disappointing one with a paucity of migrants and of a great many butterfly species certainly compared with its predecessor.

It is to be hoped that 1975 will provide a much better record.

Baron de Worms, M.A., Ph.D., F.L.S., F.R.E.S., M.B.O.U., Three Oaks, Shore's Road, Horsell, Woking, Surrey.