Suffolk butterflies, 1984

SUFFOLK BUTTERFLIES, 1984 H O W A R D M E N D E L a n d STEVE H . P I O T R O W S K I

This is the second separate butterfly report outlining the relative status of each species recorded in the County, and the earliest and latest dates on the wing in 1984, where sufficient records have been received to m a k e these meaningful. T h e 'Butterflies of Suffolk - and Atlas and History' will be published later this year providing a fĂźll account of each species.

Small Skipper, Thymelicus sylvestris ( 3 0 / 6 - G t . Blakenham: 3 0 / 8 - G t . Blakenham) Widely distributed throughout the County but sometimes difficult to locate because of their fast flight, and liable to be confused with the Essex Skipper.

Essex Skipper, Thymelicus lineola (8/7 - Blackthorpe: 30/8 - Lackford) Extremely plentiful in 1984, easily outnumbering the Small Skipper in many south Suffolk localities. T h e species reaches the north-eastern limit of its ränge in Suffolk.

Large Skipper, Ochlodes venata (27/6 - Stradishall Airfield: 27/8 - Lakenheath) Widespread in Suffolk along lanes and woodland edges. T h e colony of freshly emerged specimens at Lakenheath on 27th August, well after the species had finished over most of the County, indicated a possible second brood.

Dingy Skipper, Erynnis tages T h e r e were so few records for this fast declining species, now restricted to a few breckland localities, that first and last sightings would be meaningless.

Grizzled Skipper, Pyrgus

malvae

T h e r e have still not been any confirmed records for this species since 1979.

Clouded Yellow, Colias croceus 1984 was bound to be a little disappointing after the superb season of 1983.

Only a handful of records of this migrant species were received.

Brimstone, Gonepteryx rhamni ( 6 / 3 - B a y l h a m : 1 5 / 1 0 - G t . Blakenham) Always one of the first butterflies to be seen, emerging from hibernation at the first hint of spring. Most plentiful towards the west of the County, but surprisingly common in the east, in spite of the general absence of Buckthorn (.Rhamnus catharticus L.) and Alder Buckthorn (Frangula alnus Mill.) the larval foodplants.

Large W h i t e , Pieris brassicae ( 2 2 / 4 - Ilketshall St. Lawrence: 1 2 / 9 - W i c k h a m Market) Surprisingly scarce in the early part of the season, in contrast with its relative a b u n d a n c e in 1983. T h e larvae of this species are known to suffer badly f r o m the ravages of parasitic wasps, and this is one possible explanation for the collapse of the population.

Trans. Suffolk

Nat. Soc. 21

SUFFOLK BUTTERFLIES,

1984

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Small White, Pieris rapae ( 1 2 / 4 - G t . Blakenham: 2 7 / 1 0 - L a n d g u a r d ) A very common and widespread species with two and sometimes three broods in a season.

Green-veined White, Pieris napi ( 2 6 / 4 - Flowton: 9/9 - Beccles) Abundant and as widespread as the Small White, with which it may easily be confused on the wing.

Orange Tip, Anthocaris cardamines ( 1 6 / 4 - Sudbourne: 1 / 7 - L a k e n h e a t h ) Another good year and long season for this widespread species, in spite of the poor spring.

Green Hairstreak, Callophrys rubi (28/4 - King's Forest: 8/7 - West Stow) The ränge of this species in the County appears to be contracting, and it is now only rarely found away from the heaths of the sandlings and breck.

Purple Hairstreak, Quercusia quercus A well distributed though local species, easily overlooked because of its small size and habit of Aying about the higher branches of oaks, the larval food plant.

White-letter Hairstreak, Strymonidia w-album Many more colonies of this most easily overlooked species were found in 1984. The loss of elms, the larval foodplant, as a result of Dutch elm disease does not seem to have affected the species as badly as was once feared.

Small Copper, Lycaena phlaeas (26/4-Bawdsey: 1/11 - S o u t h w o l d ) A widely distributed and generally common species especially plentiful on heathland edges. There are normally three broods in the season.

Silver-studded Blue, Plebejus argus A very good year for this declining and threatened species. No additional sites were located in 1984, and counts showed that the colony on Martlesham Heath was as large as all the others in the County put together.

Brown Argus, Aricia agestis (9/6 - Claydon: 27/8 - Lakenheath) Very few records were received for this species, which seems to be confined to the Breckland and a small area of the Gipping Valley.

Common Blue, Polyommatus icarus (30/5 - Needham Market: 27/9 - Lowestoft) As the name would suggest, this is the most common and widely distributed of the 'blues', especially plentiful on heathlands.

Holly Blue, Celastrina argiolus (20/4 - Shotley: 1/11 - Landguard) The normal second brood of this species was over by early September and it is difficult to explain the incredibly late specimen(s) seen at Landguard by several observers, between 27th October, and Ist November. If it was a partial third brood it would be extremely unusual.

Trans. Suffolk Nat. Soc. 21

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Suffolk Natural History, Vol. 21

White Admiral, Ladoga Camilla Again plentiful at the known sitesin both east and west Suffolk, and covering a wider area than was at first thought.

Red Admiral, Vanessa atlanta (12/6-Shimpling: 1/11 - Walberswick) A generally poor year for this our most regulär migrant species. Observations made at Landguard in October suggest a return migration for which there is already considerable evidence.

Painted Lady, Cynthia cardui In common with the other spring migrants numbers were well down in 1984, and there were records from under twenty localities.

Small Tortoiseshell, Aglais urticae ( 5 / 3 - G t . Waldingfield: 27/10-Carlton Colville) Although numbers were well down in 1983 the species seems to have made a good recovery and was once again one of the commonest and widespread species throughout the County.

Camberwell Beauty, Nymphalis antiopa Undoubtedly the best year for this rare late summer migrant since 1976.

There were at least five records from Suffolk, and many people were fortunate to see the specimen at Brantham. It was first seen on the 15th August and remained for a second day imbibing sap oozing from a wound in an oak tree. Interestingly its appearance coincided with a large fall of Pied Flycatchers (Ficedula hypoleuca) at Landguard, giving weight to the belief that it was a true migrant from northern Europe.

Peacock, Inachis io (7/3 - Bosmere: 1/11 - Sutton Common) As usual one of the first species to be seen in the spring, emerging from hibernation on sunny days in early March. It is a common and very noticeable species throughout the County.

Comma, Polygonia c-album (5/4 - Rendlesham Forest: 26/9 - Mickfield) The least common of Suffolk species which hibernate in the adult stage.

Widespread, but somewhat down in numbers compared with 1983.

Speckled Wood, Pararge aegeria Surprisingly few records for this species were received during 1984. Although it is expanding in ränge from its headquarters in the Breck there are still no confirmed records from east Suffolk.

Wall, Lasiommata megera (24/5 - Aldringham: 3/10 - Bramford) A strong second brood made up for the low numbers in May and June. The Wall is a widespread though local species of open ground.

Grayling, Hipparchia semele (21/7 - High Street, nr Iken: 30/8 - Tunstall Forest) Very much a heathland species, all but a very few colonies confined to the Sandlings and Breck. Even on the heathlands it is now a local butterfly.

Trans. Suffolk Nat. Soc. 21

SUFFOLK BUTTERFLIES, 1984

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Gatekeeper, Pyronia tithonus (7/7 - Dedham: 7/9 - Burgh Castle) A common and widespread species of hedgerows and lanes.

Meadow Brown, Maniola jurtina (26/6- Raydon: 16/9 - Landguard) The most numerous and widespread of the Suffolk butterflies thriving on even small areas of rough grassland, and now recorded from nearly every tetrad in the County.

Small Heath, Coenonympha pamphilus (24/5 - Landguard: 15/9 - Ipswich) A common butterfly of rough grassland, especialy common in the dryer heathland areas but equally at home on suitable roadside verges.

Ringlet, Aphantopus hyperantus (5/7 - Earl Stonham: 27/8 - Brandon) Apparently more common in recent years, this species favours sheltered areas such as woodland rides and was once again plentiful throughout Suffolk, though least common in the south east.

Sincere thanks to the many naturalists whose records have made this report possible.

Howard Mendel and Steve H. Piotrowski The Suffolk Biological Records Centre The Museum High Street Ipswich IPI 3QH

The Suffolk Barn Owl Enquiry Particularly in the last 30 years the Suffolk countryside has changed significantly, mainly due to modern agricultural practices, and so it is interesting to see how species such as the Barn Owl have responded to these changes.

A national survey in 1932 showed that Suffolk then had approximately 700 pairs of nesting Barn Owls, most Suffolk farms having a nesting pair.

Following the massive response to the survey which began in 1983 we know that Suffolk's Barn Owl population remains substantial compared with many other districts of Britain but has decreased by about 80% in the last 50 years.

The centre of population appears to have moved from the west and south western parts of the county to the east of Suffolk.

At the time of writing the enquiry has not been completed. With more than 700 records to analyse the task has been a considerable one, but I hope to publish the results in the autumn of 1985 and Members will be notified when this takes place.

I thank Members who sent in records on Barn Owls and the staff of the Suffolk Biological Records Centre who collected all this information for me.

J. R. Martin Trans. Suffolk Nat. Soc. 21