A Review of British Lepidoptera for 1966

A REVIEW OF BRITISH LEPIDOPTERA FOR 1966 BARON DE W O R M S

A comparatively mild period during the first two months of the year was responsible for the early appearance of most of the first species to emerge. The Yellow Horned (Achlya flavicornis, Linn.) was well out by the third week in February together with many hibernated butterflies which seemed to have survived the winter period very well. March turned out a very mild and propitious month which brought the first wave of immigrants during its first half when quite a number of the Painted Lady (Pyrameis cardui, Linn.) were observed mainly in south coast areas of England.

This boded well for the subsequent phenomenal numbers of this butterfly which were seen throughout the summer months. But the very precocious season received a rude shock when a very heavy snowstorm with a bitter frost supervened in the middle of April.

Most species were back to their normal time of emergence by early May which saw quite a profusion in some localities of that delightful little butterfly the Duke of Burgundy (Hamearis lucina, Linn.).

The Orange-tip (Anthocharis cardamines, Linn.) also had a good year. It was towards the end of May that a second big migration wave apparently Struck the south coast bringing with it many of the small noctuid moth, the Small Mottled Willow (Laphygma exigua, H체bn.) and it would seem a host of the Humming-bird Hawk (Macroglossa stellatarum, Linn.) there was probably a further invasion of the Painted Lady. One lepidopterist said he saw these last two insects Aying in hundreds along a Stretch of the South Devon coast the last ten days of May. As so often happens, there was some really warm weather during the first ten days of June which brought quite an outburst of some species, in particular of the Cream-spot Tiger (Arctia villica, Linn.) which was in unusual numbers in some areas, especially in Kent. On the night of the 1 Ith June there was a most remarkable capture at Aldwick Bay in Sussex. A specimen of the Prominent moth (Hoplitis milhauseri, Fab.) was taken at a mercury vapour trap there. It was the first example of this generally scarce insect for the British Isles. This species is chiefly a denizen of the Mediterranean regions, though of recent years it has spread into Northern France and Denmark. It is doubtless gradually extending its r채nge, possibly to our shores. Only one Marsh Moth (Hydrillula palustris, H체bn.) was recorded at this period in the fens.

One or two Striped Hawks (Celerio livornica, Esp.) also appeared along the south coast in the latter days of May and in early June.

The second half of this month brought some unexpected visitors.

During the the third week in June two examples of Blair's Mocha (Cosymbia puppillaria, H체bn.) were taken at Dover, a region which had not previously produced this geometer and in fact its most easterly record for the British Isles. The Scarce Olive-tree Pearl

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(Palpita unionalis, Hübn.) was also captured in this area at this period.

The turn of the year saw the emergence in exceptional numbers of several species of our commoner butterflies, mainly in Devon and Cornwall where such insects as the Marbled White (Melanargia galatea, Linn.), the Grayling (Eumenis semele, Linn.), and even the Gatekeeper (Maniola tithonus, Linn.) were in great plenty. This local abundance was most encouraging considering some reports on the apparent general scarcity of most of our butterflies. Once more the Dark Green Fritillary (Argynnis aglaia, Linn.) virtually swarmed on some of the Wiltshire downs.

T h e Purple Emperor (Apatura iris, Linn.) had quite a good year again in its several restricted regions. Most noteworthy was the capture of this fine butterfly by a young schoolboy in mid-July in north-west Middlesex on the outskirts of the Metropolitan area. It had not been apparently recorded since the end of the last Century from this semi-populated region. Towards the end of July the Chalk-hill Blue (Lysandra coridon, Poda) was quite abundant in some of its downland localities. It was at this period that the Clouded Yellows (Colias croceus, Fourcroy) began to appear on the south coast from Kent to Cornwall tili they were eventually more numerous than for many years. In early August the many Painted Ladies (Pyrameis cardui, Linn.) which had come over in the spring produced a further generation in plenty probably supplemented by a second immigration. Düring this month in almost every garden, certainly those which provided buddleias, were to be seen these butterflies throughout the southern half of England. Many penetrated to the northernmost parts of the Kingdom. 1966 was indeed one of the best "cardui" seasons this Century. The Red Admiral (Pyrameis atalanta, Linn.) too appeared in very big numbers during the late summer all over the south. Some of the moths too were in spate. Our northern counties and Scotland saw a profusion of the noctuid, the Barred Chestnut (Diarsia dahlii, Hübn.), while those who ran mercury vapour lights in and around the Lake District in late July obtained a number of the newly separated Plusia gracilis, Lempke which bears close similarity to the much more widespread Gold Spot (Plusia festucae, Linn.).

As in most years it was the early autumn of 1966 which provided some of the most interesting records, though August was almost equally rieh in migrants. That delightful little geometer, the Vestal (Rhodometra sacraria, Linn.) began turning up in the south during the middle of the month and was taken sporadically well into October. Another frequent visitor to these shores, the Gern (Nysterosea obstipata, Fabr.) was equally numerous over a wide area, mainly in the south. But it was in early September that there took place probably the most remarkable Visitation of the year,

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that of the White-speck YVainscot (Leucania unipuncta, Haworth).

This noctuid moth was seen in dozens in some places along the south coast from Kent to Cornwall and also in South Wales.

It even penetrated well inland where it has seldom been reported.

It was indeed a record year for this species which may have bred on a big scale from spring immigrants. With the advent of autumn proper came a profusion of the commoner migrants, the Pearly Underwing (Peridroma porphyrea, Schiff.) and the Dark Dart (Agrotis ipsilon, Rott.). Both these insects which are sometimes pests abroad, were in thousands on occasion as also was the Silver-Y (Plusia gamma, Linn.) in some parts of the West Country. But there was a distinct absence of the larger immigrant Hawkmoths. Only a handful of the Death's Head (Acherontia atropos, Linn.) and of the Convolvulus (Herse convolvuli, Linn.) were reported. At least three of that grand noctuid, the Clifden Nonpareil (Catocala fraxini, Linn.) were recorded from as far apart as Worcester, Derby, and north Somerset, all in September. Two other local noctuids which had a good season were the Butterbur (Hydraecia petasitis, Doubleday) and the Stout Dart (Spaelotis ravida, Hübn.), both in late August.

October also saw quite a sprinkling of migrants among which were the Pyrales (Palpita unionalis, Hübn.), the Scarce Olive-tree Pearl, and a single example of the very rare Yellow-underwinged Pearl (Uresiphitapolygonalis, Schiff.) taken in Hampshire. Düring this period its small relative, the Rusty Dot Pearl (Hapaliaferrugalis Hebn.) was in countless thousands over most of the southern counties. The Small Mottled Willow (Laphygma exigua, Hübn.) went on well into the late autumn which saw the arrival of one or two Silver-striped Hawks (Hippotion celerio, Linn.). Düring November the Plumed Prominent (Ptilophora plumigera, Esp.) was taken in some new localities on the south downs.

Thus ended a year which promised well, but though it produced some migrants in spectacular numbers, it could not be called one of great profusion for lepidoptera in general.