The Extinction of Aporia crataegi in Britain.
Oct 11, 2016 13:01:12 GMT
deliasfanatic, mygos, and 4 more like this
Post by nomad on Oct 11, 2016 13:01:12 GMT
The Extinction of Aporia crataegi in Britain.
In Europe and across temperate Asia, the Black-veined White, Aporia crataegi will be a familiar native butterfly among Lepidoperists. It was once a fairly widespread but local species in Britain but it was already disappearing from some English Counties by the early part of the 19th Century. It has been widely accepted by nearly all the authors of the British butterfly books that the last records of this butterfly were from Herne Bay in Kent during the 1920s.
In one of the most popular modern accounts of British Butterflies, 'The Butterflies of Britain and Ireland' first published in 1991 with a recent edition of that book, the author Jeremy Thomas wrote of Aporia crataegi " So extensive was the decline that the butterfly was not seen at all in Kent in 1875-82." In Moths and Memories written by P.B.M. Allan in his chapter the ' Black-veined White', he gives a detailed history of this butterfly in Britain. Allan recorded that Aporia crataegi had in fact disappeared from Kent by 1872 and according to that author the last authentic British record as native species was a single specimen caught in its old favourite haunt the New Forest in 1880.
After the butterfly vanished from Kent in the early 1870s, a number of collectors including the famous Lepidopterist James Tutt searched all the old localities for Aporia crataegi in that County without seeing a single specimen. It was James Tutt who lived at Strood near Rochester in Kent who recorded that he caught the last specimen of Aporia crataegi in 1872 in that county. Then after being seemingly absent from Kent for fifteen years (one or two singletons were reported during that time but not authenticated), several were apparently taken in a lane near Sandwich during 1887 by a Man called Burton who said he was collecting for his friend, an entomological policeman! While Tutt thought that the Sandwich captures were the last British authentic records of our indigenous butterfly, Allan thought they were likely to be the work of ' The Kentish Buccaneers'. That fraudster George Parry of Canterbury was still very active during that period.
The news of the disappearance of Aporia crataegi surprisingly even at that early date, caused concern among many British entomologists and Tutt mentions hundreds of Continental specimens were then released in Kent and elsewhere to try to reestablish the butterfly.
Aporia crataegi from the New Forest. Bristol City Museum Collections.
Aporia crataegi then mysterious reappeared again in North-east Kent just like the mythological Phoenix arising from the ashes of its predecessor. Apparently there was a hidden colony in North-east Kent that had managed to evade all the numerous collectors who had searched area many times previously. This colony must have been a strong one for Aporia crataegi was then able to spread back along the Stour Valley and actually for a couple of years it was reasonably common until the final decline set in a few years later. Thomas (1991) records that there was a British colony of Aporia crataegi that survived until 1924 at Craycombe in Worcestershire. The Worcestershire record was I believe based on a single sighting and it is quite possible this specimen of Aporia crataegi was just the release of a captive bred butterfly. It has been suggested by Thomas and others that all the releases of bred specimens of Aporia crataegi ended in failure but since butterflies disperse how can anyone be sure that the reappearance of Aporia crataegi in Kent was not due to such reintroductions.
Aporia crataegi has never been regarded as a migratory species to Britain. Dr C.B. Williams the author of Insect Migration in The New Naturalist series of books published by Collins in 1958, said there was no evidence of immigration anywhere of this species in Britain.
The question must be why after being seemly being absent for fifteen years, Aporia crataegi suddenly turned up again in Kent. P.B.M. Allan believed that some of those reintroductions in Kent were successful at least for a few years and were continually topped up by entomologists and the other sightings elsewhere were due to the release of specimens. George Parry of Canterbury and the more respectable butterfly farmer L.W. Newman of Bexley in Kent, always had a large breeding stock of continental Aporia crataegi for sale.
P.B.M. Allan summed up his History of this butterfly in his book 'Moths and Memories' by mentioning " The entomological and other magazines, newspapers even, contain a considerable number of articles, notes and letters from correspondents, announcing the existence of the Black-veined White butterfly in some County or other down almost to the present day, but the extinction of our indigenous race elsewhere than in Hampshire before 1880, almost a decade before, is hardly open to doubt. For my part I consider any suggestion of survival after that date to be only 'wishful thinking on the part of those who admit only British caught specimens to their cabinets: these continuous records refer to the progeny of re-introductions from the Continent. There can be no question of the bona fides communications: without doubt some hundreds of Aporia crataegi -have been caught and seen in various parts of England during the last sixty years; but it is equally safe to assert that, so far as the ecologist is concerned, our island failed to support the indigenous race of this butterfly after 1880".
Allan had a fluent pen and he was a witty master writer and he was also a very knowledgeable field entomologist. In his account of Aporia crataegi, Allan gave detailed references to the information he provided. It does seem that Allan's idea that the native British A. crataegi died out Britain in the New Forest in 1880 went down like a lead balloon because it meant that all those specimens that were residing in cabinets as British specimens that were bred or captured in Kent and elsewhere after that date were actually from released continental stock.
Aporia crataegi specimens from the New Forest and from Bridgend, the latter locality was historically part of the County of Glamorganshire in South Wales. It is seems very likely that this specimen from Bridgend was caught by the collector Captain Blomer, who found it in that locality during 1833 and this specimen was later acquired by J.C. Dale when he obtained the Blomer collection. It was extinct in Glamorganshire by 1869.
Aporia crataegi throughout its huge range from Europe to N.W. Africa through temperate Asia to Japan shows hardly any variation; some have suggested this is a very ancient butterfly, is certainly has a primeval look about it. Why did Aporia crataegi became extinct in Britain, many reasons have been put forth, from the increase of small birds after our raptors were massacred en mass by shooting, to parasitism of the larvae. Some have suggested climate change was the nail in the coffin for A. crataegi, but this species seems to be able to survive elsewhere in diverse habitats such as arid plains of North Africa to high altitude in the Alps.
P.B.M. Allan thought that climate change was the main reason for extinction of Aporia crataegi Britain and added that is why most of the introductions of this species failed to reestablish the butterfly on a permanent footing. C.R. Pratt (1983) wrote that a " high September rainfall preceded its demise; this led to a much higher incidence of the disease which was primarily the reason for its extinction. Increased avian predation was a secondary cause, the two together presented a unique coincidence of adverse factors". It must be mentioned that Pratt was taking about the butterflies demise in Kent after its reappearance there until its extinction in 1922.
A. crataegi had certainly been on the edge of its range in Britain and it was always a local butterfly and even in its best known colonies there were yearly fluctuations in the population. However, all the ideas for its ultimate extinction must in the end be assumptions at the very best. We just do not know the true reason behind Aporia crataegi rapid decline in the 19th Century and final extinction.
Specimen of Aporia crataegi from Glanvilles Wootton in Dorset, captured by James Charles Dale in May 1808 when George III was in the throne! OUNHM coll.
Specimens of Aporia crataegi in the Dale collection from the New Forest and from Glanvilles Wootton, Dorset. J.C. Dale captured his specimen at Glanvilles Wootton on June 10 1815 at a place called Sandhills. Aporia crataegi was always very rare in the parish of Glanvilles Wootton and this was the last specimen taken by Dale there. In fact this specimen is the last authentic record from Dorset.
Summary. Does it really matter if those cherished specimens of Aporia crataegi residing in your collection are from continental stock or British, perhaps not but at least you know that you do have old specimens of this species taken before 1880 and if you agree with Allan that this butterfly became extinct during that year you do indeed have British specimens, that is unless bought them recently!! It still is an interesting and an undiscussed topic whether the British native race of Aporia crataegi became extinct in 1880 in Hampshire or over thirty years later in Kent.
In Europe and across temperate Asia, the Black-veined White, Aporia crataegi will be a familiar native butterfly among Lepidoperists. It was once a fairly widespread but local species in Britain but it was already disappearing from some English Counties by the early part of the 19th Century. It has been widely accepted by nearly all the authors of the British butterfly books that the last records of this butterfly were from Herne Bay in Kent during the 1920s.
In one of the most popular modern accounts of British Butterflies, 'The Butterflies of Britain and Ireland' first published in 1991 with a recent edition of that book, the author Jeremy Thomas wrote of Aporia crataegi " So extensive was the decline that the butterfly was not seen at all in Kent in 1875-82." In Moths and Memories written by P.B.M. Allan in his chapter the ' Black-veined White', he gives a detailed history of this butterfly in Britain. Allan recorded that Aporia crataegi had in fact disappeared from Kent by 1872 and according to that author the last authentic British record as native species was a single specimen caught in its old favourite haunt the New Forest in 1880.
After the butterfly vanished from Kent in the early 1870s, a number of collectors including the famous Lepidopterist James Tutt searched all the old localities for Aporia crataegi in that County without seeing a single specimen. It was James Tutt who lived at Strood near Rochester in Kent who recorded that he caught the last specimen of Aporia crataegi in 1872 in that county. Then after being seemingly absent from Kent for fifteen years (one or two singletons were reported during that time but not authenticated), several were apparently taken in a lane near Sandwich during 1887 by a Man called Burton who said he was collecting for his friend, an entomological policeman! While Tutt thought that the Sandwich captures were the last British authentic records of our indigenous butterfly, Allan thought they were likely to be the work of ' The Kentish Buccaneers'. That fraudster George Parry of Canterbury was still very active during that period.
The news of the disappearance of Aporia crataegi surprisingly even at that early date, caused concern among many British entomologists and Tutt mentions hundreds of Continental specimens were then released in Kent and elsewhere to try to reestablish the butterfly.
Aporia crataegi from the New Forest. Bristol City Museum Collections.
Aporia crataegi then mysterious reappeared again in North-east Kent just like the mythological Phoenix arising from the ashes of its predecessor. Apparently there was a hidden colony in North-east Kent that had managed to evade all the numerous collectors who had searched area many times previously. This colony must have been a strong one for Aporia crataegi was then able to spread back along the Stour Valley and actually for a couple of years it was reasonably common until the final decline set in a few years later. Thomas (1991) records that there was a British colony of Aporia crataegi that survived until 1924 at Craycombe in Worcestershire. The Worcestershire record was I believe based on a single sighting and it is quite possible this specimen of Aporia crataegi was just the release of a captive bred butterfly. It has been suggested by Thomas and others that all the releases of bred specimens of Aporia crataegi ended in failure but since butterflies disperse how can anyone be sure that the reappearance of Aporia crataegi in Kent was not due to such reintroductions.
Aporia crataegi has never been regarded as a migratory species to Britain. Dr C.B. Williams the author of Insect Migration in The New Naturalist series of books published by Collins in 1958, said there was no evidence of immigration anywhere of this species in Britain.
The question must be why after being seemly being absent for fifteen years, Aporia crataegi suddenly turned up again in Kent. P.B.M. Allan believed that some of those reintroductions in Kent were successful at least for a few years and were continually topped up by entomologists and the other sightings elsewhere were due to the release of specimens. George Parry of Canterbury and the more respectable butterfly farmer L.W. Newman of Bexley in Kent, always had a large breeding stock of continental Aporia crataegi for sale.
P.B.M. Allan summed up his History of this butterfly in his book 'Moths and Memories' by mentioning " The entomological and other magazines, newspapers even, contain a considerable number of articles, notes and letters from correspondents, announcing the existence of the Black-veined White butterfly in some County or other down almost to the present day, but the extinction of our indigenous race elsewhere than in Hampshire before 1880, almost a decade before, is hardly open to doubt. For my part I consider any suggestion of survival after that date to be only 'wishful thinking on the part of those who admit only British caught specimens to their cabinets: these continuous records refer to the progeny of re-introductions from the Continent. There can be no question of the bona fides communications: without doubt some hundreds of Aporia crataegi -have been caught and seen in various parts of England during the last sixty years; but it is equally safe to assert that, so far as the ecologist is concerned, our island failed to support the indigenous race of this butterfly after 1880".
Allan had a fluent pen and he was a witty master writer and he was also a very knowledgeable field entomologist. In his account of Aporia crataegi, Allan gave detailed references to the information he provided. It does seem that Allan's idea that the native British A. crataegi died out Britain in the New Forest in 1880 went down like a lead balloon because it meant that all those specimens that were residing in cabinets as British specimens that were bred or captured in Kent and elsewhere after that date were actually from released continental stock.
Aporia crataegi specimens from the New Forest and from Bridgend, the latter locality was historically part of the County of Glamorganshire in South Wales. It is seems very likely that this specimen from Bridgend was caught by the collector Captain Blomer, who found it in that locality during 1833 and this specimen was later acquired by J.C. Dale when he obtained the Blomer collection. It was extinct in Glamorganshire by 1869.
Aporia crataegi throughout its huge range from Europe to N.W. Africa through temperate Asia to Japan shows hardly any variation; some have suggested this is a very ancient butterfly, is certainly has a primeval look about it. Why did Aporia crataegi became extinct in Britain, many reasons have been put forth, from the increase of small birds after our raptors were massacred en mass by shooting, to parasitism of the larvae. Some have suggested climate change was the nail in the coffin for A. crataegi, but this species seems to be able to survive elsewhere in diverse habitats such as arid plains of North Africa to high altitude in the Alps.
P.B.M. Allan thought that climate change was the main reason for extinction of Aporia crataegi Britain and added that is why most of the introductions of this species failed to reestablish the butterfly on a permanent footing. C.R. Pratt (1983) wrote that a " high September rainfall preceded its demise; this led to a much higher incidence of the disease which was primarily the reason for its extinction. Increased avian predation was a secondary cause, the two together presented a unique coincidence of adverse factors". It must be mentioned that Pratt was taking about the butterflies demise in Kent after its reappearance there until its extinction in 1922.
A. crataegi had certainly been on the edge of its range in Britain and it was always a local butterfly and even in its best known colonies there were yearly fluctuations in the population. However, all the ideas for its ultimate extinction must in the end be assumptions at the very best. We just do not know the true reason behind Aporia crataegi rapid decline in the 19th Century and final extinction.
Specimen of Aporia crataegi from Glanvilles Wootton in Dorset, captured by James Charles Dale in May 1808 when George III was in the throne! OUNHM coll.
Specimens of Aporia crataegi in the Dale collection from the New Forest and from Glanvilles Wootton, Dorset. J.C. Dale captured his specimen at Glanvilles Wootton on June 10 1815 at a place called Sandhills. Aporia crataegi was always very rare in the parish of Glanvilles Wootton and this was the last specimen taken by Dale there. In fact this specimen is the last authentic record from Dorset.
Summary. Does it really matter if those cherished specimens of Aporia crataegi residing in your collection are from continental stock or British, perhaps not but at least you know that you do have old specimens of this species taken before 1880 and if you agree with Allan that this butterfly became extinct during that year you do indeed have British specimens, that is unless bought them recently!! It still is an interesting and an undiscussed topic whether the British native race of Aporia crataegi became extinct in 1880 in Hampshire or over thirty years later in Kent.
