The Mythical Apatura iris aberration iole Schiff 1775.
Nov 3, 2016 9:29:30 GMT
deliasfanatic, mygos, and 8 more like this
Post by nomad on Nov 3, 2016 9:29:30 GMT
The Mythical Apatura iris aberration iole Schiffermuller 1775.
Although infrasubspecific names have been excluded from the International Code of Zoological Nomenclature (ICZN, 2012) the interest in them remains undiminished. Apatura iris has long held a fascination with enthusiasts in Britain and none more so than the Holy grail of Purple Emperor aberrations, an all black example that shimmers iridescent purple in its woodland habitat. This article examines the history and specimens of Apatura iris that have been referred to ab iole Schiffermuller 1775.
A number of British specimens of A. iris that had greatly reduced upperside white wing markings have been referred to as ab. iole Denis and Schiffermuller 1775. Ignaz Schiffermuller and Michael Denis in their description of ab. iole (Wien Verg. 1775.5.p 172.) refer to a specimen of Apatura iris without any white markings on the upperside of the wings.
In the British Museum of Natural History there is a male specimen of A. iris set as an underside that has been determined as ab. iole Schiff (Fig 3). I have recently been able to obtain an image of the upperside of that specimen from the BMNH which shows that it is not quite devoid of white markings and therefore does not entirely match the description of ab. iole by Denis and Schiffermuller. I.R.P. Heslop and R.E. Stockley (1964) mention they refrained from naming undersides aberrations of specimens in the iole range because the BMNH considered ab. iole as a whole, comprising both the upperside and underside, the essential feature is the total absence of white markings on both surfaces.
The Belgian lepidopterist Canon Cabeau and others named many Apatura iris aberrations and there has been considerable confusion regarding the determination of specimens. Several specimens that were once considered to be ab. iole Schiff have now been determined as ab. lugenda Cabeau 1910. Reverend Cabeau description of ab. lugenda (Mens Soc Ent Names. 1910. p. 34) mentions the presence of three small white upper forewing spots that form a triangle and that the hindwing white transverse band is completely absent and there are only bluish hairs present. In a number of specimens that have been determined as ab. lugenda, you can still see the transverse band on the upperside of the hindwing. There are certainly some whitish hairs present.
Those A. iris specimens that have reduced white markings on the upperside of the forewings but with a more or less normal white hindwing transverse band present are referable to ab. iolata Cabeau 1910 = ab. semi-iole Frohawk 1938.
No specimens of Apatura iris have been seen in any British collections that are devoid of white markings on the upperwings. Unfortunately the A. iris specimen used by the Austrian authors Denis and Schiffermuller in their original description of ab. iole no longer exists. Sadly all the type specimens of Denis and Schiffermuller held in Vienna were destroyed during the 1848 Revolution (G. Martin pers. comm 2016). It is not known whether any other specimens in European museums resemble the description of ab. iole by Denis and Schiffermuller.
The British Museum of Natural History used exclusively the work of Goodson A.L. and Read D.K. (1969) Aberrational and Subspecific Forms of British Lepidoptera (unpublished work, British Museum of Natural History) to determine the specimens in their collection. One wonders with the interest in British Butterfly Aberrations why this work has never been published. However, according to Weir (2016) the British Museum of Natural History states that it is 'no longer museum policy to describe new aberrations of Lepidoptera'.
Figure 1 & 2. Typical A. iris specimens. Fig 1. Male specimen taken by James Charles Dale (1791–1872) in the early part of the 19th century while he was at school at Enborne, West Berkshire. Fig 2. Typical female specimen taken in the New Forest from the Dale collection. Oxford University Natural History Museum collections.
F. W. Frohawk.
F.W. Frohawk wrote in his Varieties of British Butterflies published in 1938, 'A very rare form of this fine insect, known as ab. iole Schiff, has the normal white spots much reduced in size or in number. In extreme forms they are missing, or only one or two remain. The under surface is equally aberrant, especially the hind wings, which have no trace of the normal white band, so conspicuous in normal specimens'. Frohawk chose to figure a specimen that had been in his collection which he regarded as ab. iole for the Frontispiece to his book, Varieties of British Butterflies. I.R.P. Heslop (1964) referred to Frohawk's figured specimen of ab. iole as being now regarded in museum practice as ab. lugenda. The British Museum of Natural History has now determined Frohawk's ab. iole specimen held in their collections as ab. beroe Fabricius 1793. In 1927 when he was short of money, Frohawk decided to sell his magnificent collection of six thousand British butterflies to his friend Lord Walter Rothschild for one thousand pounds, (55 thousand pounds in current values).
I.R.P. Heslop.
Ian Heslop was a well known British Lepidopterist who was a passionate A. iris observer and collector. Heslop produced with Roy Stockley and George Hyde a very fine monograph on Apatura iris, Notes and Views of the Purple Emperor that was published in 1964.
The Baron Charles de Worms (1962) in his Macrolepidoptera of Wiltshire figured the upperside of a male A. iris specimen as ab. iole on plate 11 that was taken in South Wiltshire by I.R.P. Heslop during 1960. Heslop recorded details of this capture in his diary for that year. On Monday 25th July, Heslop arrived at Whiteparish Wood, a well known Wiltshire locality for A. iris from his home Belfield in Burnham-upon-Sea, Somerset at 9.03 am. He wrote 'The sun came through at 9.06. I saw a big male Purple Emperor at 9.07 and again at 9.17. A little before 9.30 there was a flush of four males, including a semi-iole male. This perched on an outer spray of oak and I caught without difficulty with the high net without the aluminum extensions. Among the others seen at 9.30 there was again the enormous male still wary, the sun became obscured. At 10.15 the sun came out again and I caught the giant male on the ground'. Heslop added to his diary that the specimen he previously referred to as semi-iole Iris male No 3992 though a little rubbed on the upperside, was almost a full ab. iole and he mentioned the large specimen Iris male No 3993 was clearly a new aberration.
The specimen of A. Iris caught in Whiteparish Wood during July 1960 (No 3992) and referred to as upperside ab iole and figured as such by the Baron de Worms was later described by Heslop (1961) as ab. sorbioduni, due it being a unique underside aberration. There is another specimen of A. iris with no locality or date that was sold at the Bright Sale (1942), Ex Bessmer Collection and now held by the BMNH that has been determined as ab. sorbioduni Heslop. The giant male of A. iris that Heslop took during the same day at the same place as his specimen of ab. sorbioduni, exceeds in size that of many females and compares with the largest of that sex. This large male was described by Heslop (1960) as ab. maximinus.
Figure 3 & 4. Specimen of ab. sorbioduni Heslop 1961. Caught by I.R.P. Heslop on the 25th July 1960. Bristol City Museum Collections. Figured as an upperside ab. iole Schiff by the Baron de Worms in the Macrolepdoptera of Wiltshire (1962). By A.D.A Russwurm on plate XVII in Notes and Views of the Purple Emperor by Heslop, Hyde, Stockley (1964) and on Plate 36 by A.D.A. Russwurm in Variation of British Butterflies by A.S. Harmer (2000) as ab. sorbioduni Heslop.
Figure 5. Male specimen of ab. maximinus Heslop 1960. Taken by I.R.P. Heslop on the 25th July 1960 and shown here with a typical female specimen taken by Heslop in Hampshire on 21st July 1969. Bristol City Museum Collections. Figured in B/W by A.D.A. Russwurm on plate XIX in Notes and Views of the Purple Emperor by Heslop, Hyde, Stockley (1964).
Heslop and Stockley (1961,1964) wrote of A. iris ab. iole Schiff and ab. lugenda Cabeau. ' At one time specimens showing any marked diminution of white on the upperside were all referred to as ab.iole Schiff. It is only in the last forty years or so that the practice has grown up alluding to just the most extreme examples as iole and to all the intermediate ones as semi-iole. The type of semi-iole, as an upperside, appears to have been fixed for both male and female by Frohawk in 1938 (Varieties of British Butterflies, plate 25); but Cabeau has described the same thing as iolata'.
' We are advised that ab. iole Schiff has been interpreted as applying to the total absence of white markings both on the upperside and underside. Those specimens having only one to four white spots on the forewing, and no other white markings, are in Museum practice treated as ab. lugenda Cabeau. And ab. iolata (semi-iole) covers all specimens with substantial reduction of the markings. By criterion, iole is indeed an excessive rarity. There is one such specimen in the Tring Museum set underside. Here we must observe that the relative figured in South (1906), male, appears to be referable to semi-iole, as so understood not iole. The figure on the frontispiece of Frohawk " Varieties of British Butterflies" is apparently of Cabeau's lugenda'.
Heslop and Stockley (1961,1964) believed that specimens of ab. iole (ab.lugenda) and ab.iolata were produced by cold and heat shock during the changes from the larvae to the pupa and the gene that produces these aberrations is always in the species but needs to be put in motion. They further believed that there was no real justification for the distinction between ab. iole and ab lugenda, as the undersides of both fell into the same general general pattern and only the most unusual underside underside variations of A. iris such as ab. sorbioduni should be named.
One of the last Purple Emperor specimens that Heslop took was a special one. He was walking along a lane running through Beechwood Copse part of the Bentley Wood complex in Wiltshire when he encountered a magnificent A. iris aberration. Heslop's diary entry for Monday 21st July 1969 reads ' Full Ab iole. Never have I taken an insect more easily, it was just flying peacefully along its track (Howe Lane) at knee-height. Five Purple Emperors seen in all. I have been watching the moon walk until 5.30am'. This specimen shows only very slight traces of forewing white markings and it lacks the upper hindwing orange ocellus that is found in ab. lugenda. Heslops extreme A. iris aberration might be as close to ab. iole that any fortunate person is likely to get. Heslop mentions in his diary that he caught this rarity in Wiltshire but he added Hampshire to the specimen label. The capture was very close to the boundary with that County.
The same day that Heslop secured his prize aberration, he also took a male and two female specimens of A. iris that he recorded in his diary were taken in Hampshire, probably in the same woodlands. However, that Red Letter day, Heslop also visited Cowleys' Copse in the Hampshire New Forest. By the 1960s A. iris had become very scarce or unknown in most of the large New Forest woodlands.
Figure 6 & 7. Male A. iris aberration caught by I.R.P. Heslop on 21st July 1969 and determined by him as ab iole Schiff. British City Museum Collections.
Figure 8 & 9. Male A. iris specimen in the Oxford University Museum of Natural History collections. Perhaps referable to ab. beroe Fabricius 1793? Taken on the 27th June 1934.
Figure 10. Male Apatura iris specimen from the Dale collection labelled ab. iole Schiff but perhaps referable to ab. lugenda Cabeau? This specimen is also a most unusual aberration in that the hindwings are asymmetrical. Ex J.G. Ross collection, taken in 1879 and acquired by Charles William Dale. OUNHM collections.
Piers Vigus who has studied the aberrations of A. iris has given me his thoughts on ab. iole and many thanks to him for his permission to use his comments here. He writes
'From my perspective certainly pertaining to English caught specimens - I can not comment upon those from continental populations - ab. iole became (and remains) almost mythological in terms of the likelihood of being able to secure a specimen (or photograph)'.
'The concept of an iris which is totally devoid of markings (both the white markings as well as the ocellus to which you refer) is, perhaps, more of an idea, an aspiration, the grail of iris aberrations; rather than a reality'.
'Schiffermuller when he described the aberration in the 1770s, simply stated "...upperside completely black-brown with a blue shimmer and no white markings'.
'If we are to take Schiffermuller's description at face value, then to be a 'true iole' the specimen would surely have to be exactly that - utterly devoid of markings. And there lies the lure which kept the old collectors returning to the woods year after year - the search for the very zenith of iris aberrations, the prize which would be the envy of their contemporaries; and it surely remains a lure to some even today'?
'Whether or not a specimen even exists to match this description, I do not know; and part of me even secretly hopes that it doesn't, and that ab.iole remains the enigma that it has become'.
'From my personal perspective, the idea of a mythical creature, a grail of iris aberrations, which evaded our entomological brethren of old, is far more appealing than the concept of being able to visit a museum or personal collection and view a specimen'.
'In these modern time we surely need such things of entomological legend and folklore more than ever; and our lives would be less rich were the unobtainable actually achieved'.
Artificially Produced Butterfly Aberrations.
Recently there has been many man made butterfly aberrations that have been obtained through artificial cold or heat shock to the pupa. Another dubious method of obtaining melanic aberrations has been by Chemical injection of the pupae. As has been mentioned in the article, A. iris aberrations are thought to be produced in the wild from extreme heat or cold shock at a critical stage of the pupa. This article is exclusively about aberrations of Apatura iris that has occurred naturally in Britain, either as an adult that has been observed in its woodland habitat or one that has been bred from a wild collected larvae.
Acknowledgments. I would like to thank Geoff Martin of the British Museum of Natural History for information and images. Rhian Rowland of the Bristol City Museum for permission to view Ian Heslop's Specimens & Diaries. James Hogan at the Oxford University Museum of Natural History for permission to visit and photograph the collections in the Hope Department of Entomology and to Piers Vigus for his thoughts on A. iris ab. iole.
References.
Note. All the articles by Ian Heslop written for the Entomological Journals that are listed below were later included as papers No 29, No 32, and No 33 in the Monograph (1964) Notes and Views of the Purple Emperor.
Frohawk F.W. (1938) Varieties of British Butterflies.
Goodson A.L. and Read D.K. (1969) Aberrational and Subspecific Forms of British Lepidoptera (unpublished work, British Museum of Natural History).
Harmer A.S. (2000) Variation in British Butterflies.
Heslop I.R.P (1960) A New Male Aberration of Apatura Iris (Linnaeus) (Lep. Nymphalidae) Entomologist Vol. 93. p.251.
Heslop I.R.P. (1961) Two New Aberrations of Apatura Iris Linnaeus. Entomologist's Record and Journal of Variation Vol 73 p. 58.
Heslop. I.R.P (1961) Aspects of Variation in Apatura Iris with the Description of one New Aberration. Entomologist's Record and Journal of Variation. Vol 73. p.73.
Heslop I.R.P., Hyde, G.E. and Stockley, R.E. (1964) Notes and Views of the Purple Emperor.
Heslop I.R.P. Diaries accessed 2016. Bristol City Museum.
Howarth T.G. (1973) South's British Butterflies.
Weir J.C. (2016) British Journal of Entomology. Intraspecific Taxonomy in the Lepidoptera.Vo1 29, part 3, p. 144.
Although infrasubspecific names have been excluded from the International Code of Zoological Nomenclature (ICZN, 2012) the interest in them remains undiminished. Apatura iris has long held a fascination with enthusiasts in Britain and none more so than the Holy grail of Purple Emperor aberrations, an all black example that shimmers iridescent purple in its woodland habitat. This article examines the history and specimens of Apatura iris that have been referred to ab iole Schiffermuller 1775.
A number of British specimens of A. iris that had greatly reduced upperside white wing markings have been referred to as ab. iole Denis and Schiffermuller 1775. Ignaz Schiffermuller and Michael Denis in their description of ab. iole (Wien Verg. 1775.5.p 172.) refer to a specimen of Apatura iris without any white markings on the upperside of the wings.
In the British Museum of Natural History there is a male specimen of A. iris set as an underside that has been determined as ab. iole Schiff (Fig 3). I have recently been able to obtain an image of the upperside of that specimen from the BMNH which shows that it is not quite devoid of white markings and therefore does not entirely match the description of ab. iole by Denis and Schiffermuller. I.R.P. Heslop and R.E. Stockley (1964) mention they refrained from naming undersides aberrations of specimens in the iole range because the BMNH considered ab. iole as a whole, comprising both the upperside and underside, the essential feature is the total absence of white markings on both surfaces.
The Belgian lepidopterist Canon Cabeau and others named many Apatura iris aberrations and there has been considerable confusion regarding the determination of specimens. Several specimens that were once considered to be ab. iole Schiff have now been determined as ab. lugenda Cabeau 1910. Reverend Cabeau description of ab. lugenda (Mens Soc Ent Names. 1910. p. 34) mentions the presence of three small white upper forewing spots that form a triangle and that the hindwing white transverse band is completely absent and there are only bluish hairs present. In a number of specimens that have been determined as ab. lugenda, you can still see the transverse band on the upperside of the hindwing. There are certainly some whitish hairs present.
Those A. iris specimens that have reduced white markings on the upperside of the forewings but with a more or less normal white hindwing transverse band present are referable to ab. iolata Cabeau 1910 = ab. semi-iole Frohawk 1938.
No specimens of Apatura iris have been seen in any British collections that are devoid of white markings on the upperwings. Unfortunately the A. iris specimen used by the Austrian authors Denis and Schiffermuller in their original description of ab. iole no longer exists. Sadly all the type specimens of Denis and Schiffermuller held in Vienna were destroyed during the 1848 Revolution (G. Martin pers. comm 2016). It is not known whether any other specimens in European museums resemble the description of ab. iole by Denis and Schiffermuller.
The British Museum of Natural History used exclusively the work of Goodson A.L. and Read D.K. (1969) Aberrational and Subspecific Forms of British Lepidoptera (unpublished work, British Museum of Natural History) to determine the specimens in their collection. One wonders with the interest in British Butterfly Aberrations why this work has never been published. However, according to Weir (2016) the British Museum of Natural History states that it is 'no longer museum policy to describe new aberrations of Lepidoptera'.
Figure 1 & 2. Typical A. iris specimens. Fig 1. Male specimen taken by James Charles Dale (1791–1872) in the early part of the 19th century while he was at school at Enborne, West Berkshire. Fig 2. Typical female specimen taken in the New Forest from the Dale collection. Oxford University Natural History Museum collections.
F. W. Frohawk.
F.W. Frohawk wrote in his Varieties of British Butterflies published in 1938, 'A very rare form of this fine insect, known as ab. iole Schiff, has the normal white spots much reduced in size or in number. In extreme forms they are missing, or only one or two remain. The under surface is equally aberrant, especially the hind wings, which have no trace of the normal white band, so conspicuous in normal specimens'. Frohawk chose to figure a specimen that had been in his collection which he regarded as ab. iole for the Frontispiece to his book, Varieties of British Butterflies. I.R.P. Heslop (1964) referred to Frohawk's figured specimen of ab. iole as being now regarded in museum practice as ab. lugenda. The British Museum of Natural History has now determined Frohawk's ab. iole specimen held in their collections as ab. beroe Fabricius 1793. In 1927 when he was short of money, Frohawk decided to sell his magnificent collection of six thousand British butterflies to his friend Lord Walter Rothschild for one thousand pounds, (55 thousand pounds in current values).
I.R.P. Heslop.
Ian Heslop was a well known British Lepidopterist who was a passionate A. iris observer and collector. Heslop produced with Roy Stockley and George Hyde a very fine monograph on Apatura iris, Notes and Views of the Purple Emperor that was published in 1964.
The Baron Charles de Worms (1962) in his Macrolepidoptera of Wiltshire figured the upperside of a male A. iris specimen as ab. iole on plate 11 that was taken in South Wiltshire by I.R.P. Heslop during 1960. Heslop recorded details of this capture in his diary for that year. On Monday 25th July, Heslop arrived at Whiteparish Wood, a well known Wiltshire locality for A. iris from his home Belfield in Burnham-upon-Sea, Somerset at 9.03 am. He wrote 'The sun came through at 9.06. I saw a big male Purple Emperor at 9.07 and again at 9.17. A little before 9.30 there was a flush of four males, including a semi-iole male. This perched on an outer spray of oak and I caught without difficulty with the high net without the aluminum extensions. Among the others seen at 9.30 there was again the enormous male still wary, the sun became obscured. At 10.15 the sun came out again and I caught the giant male on the ground'. Heslop added to his diary that the specimen he previously referred to as semi-iole Iris male No 3992 though a little rubbed on the upperside, was almost a full ab. iole and he mentioned the large specimen Iris male No 3993 was clearly a new aberration.
The specimen of A. Iris caught in Whiteparish Wood during July 1960 (No 3992) and referred to as upperside ab iole and figured as such by the Baron de Worms was later described by Heslop (1961) as ab. sorbioduni, due it being a unique underside aberration. There is another specimen of A. iris with no locality or date that was sold at the Bright Sale (1942), Ex Bessmer Collection and now held by the BMNH that has been determined as ab. sorbioduni Heslop. The giant male of A. iris that Heslop took during the same day at the same place as his specimen of ab. sorbioduni, exceeds in size that of many females and compares with the largest of that sex. This large male was described by Heslop (1960) as ab. maximinus.
Figure 3 & 4. Specimen of ab. sorbioduni Heslop 1961. Caught by I.R.P. Heslop on the 25th July 1960. Bristol City Museum Collections. Figured as an upperside ab. iole Schiff by the Baron de Worms in the Macrolepdoptera of Wiltshire (1962). By A.D.A Russwurm on plate XVII in Notes and Views of the Purple Emperor by Heslop, Hyde, Stockley (1964) and on Plate 36 by A.D.A. Russwurm in Variation of British Butterflies by A.S. Harmer (2000) as ab. sorbioduni Heslop.
Figure 5. Male specimen of ab. maximinus Heslop 1960. Taken by I.R.P. Heslop on the 25th July 1960 and shown here with a typical female specimen taken by Heslop in Hampshire on 21st July 1969. Bristol City Museum Collections. Figured in B/W by A.D.A. Russwurm on plate XIX in Notes and Views of the Purple Emperor by Heslop, Hyde, Stockley (1964).
Heslop and Stockley (1961,1964) wrote of A. iris ab. iole Schiff and ab. lugenda Cabeau. ' At one time specimens showing any marked diminution of white on the upperside were all referred to as ab.iole Schiff. It is only in the last forty years or so that the practice has grown up alluding to just the most extreme examples as iole and to all the intermediate ones as semi-iole. The type of semi-iole, as an upperside, appears to have been fixed for both male and female by Frohawk in 1938 (Varieties of British Butterflies, plate 25); but Cabeau has described the same thing as iolata'.
' We are advised that ab. iole Schiff has been interpreted as applying to the total absence of white markings both on the upperside and underside. Those specimens having only one to four white spots on the forewing, and no other white markings, are in Museum practice treated as ab. lugenda Cabeau. And ab. iolata (semi-iole) covers all specimens with substantial reduction of the markings. By criterion, iole is indeed an excessive rarity. There is one such specimen in the Tring Museum set underside. Here we must observe that the relative figured in South (1906), male, appears to be referable to semi-iole, as so understood not iole. The figure on the frontispiece of Frohawk " Varieties of British Butterflies" is apparently of Cabeau's lugenda'.
Heslop and Stockley (1961,1964) believed that specimens of ab. iole (ab.lugenda) and ab.iolata were produced by cold and heat shock during the changes from the larvae to the pupa and the gene that produces these aberrations is always in the species but needs to be put in motion. They further believed that there was no real justification for the distinction between ab. iole and ab lugenda, as the undersides of both fell into the same general general pattern and only the most unusual underside underside variations of A. iris such as ab. sorbioduni should be named.
One of the last Purple Emperor specimens that Heslop took was a special one. He was walking along a lane running through Beechwood Copse part of the Bentley Wood complex in Wiltshire when he encountered a magnificent A. iris aberration. Heslop's diary entry for Monday 21st July 1969 reads ' Full Ab iole. Never have I taken an insect more easily, it was just flying peacefully along its track (Howe Lane) at knee-height. Five Purple Emperors seen in all. I have been watching the moon walk until 5.30am'. This specimen shows only very slight traces of forewing white markings and it lacks the upper hindwing orange ocellus that is found in ab. lugenda. Heslops extreme A. iris aberration might be as close to ab. iole that any fortunate person is likely to get. Heslop mentions in his diary that he caught this rarity in Wiltshire but he added Hampshire to the specimen label. The capture was very close to the boundary with that County.
The same day that Heslop secured his prize aberration, he also took a male and two female specimens of A. iris that he recorded in his diary were taken in Hampshire, probably in the same woodlands. However, that Red Letter day, Heslop also visited Cowleys' Copse in the Hampshire New Forest. By the 1960s A. iris had become very scarce or unknown in most of the large New Forest woodlands.
Figure 6 & 7. Male A. iris aberration caught by I.R.P. Heslop on 21st July 1969 and determined by him as ab iole Schiff. British City Museum Collections.
Figure 8 & 9. Male A. iris specimen in the Oxford University Museum of Natural History collections. Perhaps referable to ab. beroe Fabricius 1793? Taken on the 27th June 1934.
Figure 10. Male Apatura iris specimen from the Dale collection labelled ab. iole Schiff but perhaps referable to ab. lugenda Cabeau? This specimen is also a most unusual aberration in that the hindwings are asymmetrical. Ex J.G. Ross collection, taken in 1879 and acquired by Charles William Dale. OUNHM collections.
Piers Vigus who has studied the aberrations of A. iris has given me his thoughts on ab. iole and many thanks to him for his permission to use his comments here. He writes
'From my perspective certainly pertaining to English caught specimens - I can not comment upon those from continental populations - ab. iole became (and remains) almost mythological in terms of the likelihood of being able to secure a specimen (or photograph)'.
'The concept of an iris which is totally devoid of markings (both the white markings as well as the ocellus to which you refer) is, perhaps, more of an idea, an aspiration, the grail of iris aberrations; rather than a reality'.
'Schiffermuller when he described the aberration in the 1770s, simply stated "...upperside completely black-brown with a blue shimmer and no white markings'.
'If we are to take Schiffermuller's description at face value, then to be a 'true iole' the specimen would surely have to be exactly that - utterly devoid of markings. And there lies the lure which kept the old collectors returning to the woods year after year - the search for the very zenith of iris aberrations, the prize which would be the envy of their contemporaries; and it surely remains a lure to some even today'?
'Whether or not a specimen even exists to match this description, I do not know; and part of me even secretly hopes that it doesn't, and that ab.iole remains the enigma that it has become'.
'From my personal perspective, the idea of a mythical creature, a grail of iris aberrations, which evaded our entomological brethren of old, is far more appealing than the concept of being able to visit a museum or personal collection and view a specimen'.
'In these modern time we surely need such things of entomological legend and folklore more than ever; and our lives would be less rich were the unobtainable actually achieved'.
Artificially Produced Butterfly Aberrations.
Recently there has been many man made butterfly aberrations that have been obtained through artificial cold or heat shock to the pupa. Another dubious method of obtaining melanic aberrations has been by Chemical injection of the pupae. As has been mentioned in the article, A. iris aberrations are thought to be produced in the wild from extreme heat or cold shock at a critical stage of the pupa. This article is exclusively about aberrations of Apatura iris that has occurred naturally in Britain, either as an adult that has been observed in its woodland habitat or one that has been bred from a wild collected larvae.
Acknowledgments. I would like to thank Geoff Martin of the British Museum of Natural History for information and images. Rhian Rowland of the Bristol City Museum for permission to view Ian Heslop's Specimens & Diaries. James Hogan at the Oxford University Museum of Natural History for permission to visit and photograph the collections in the Hope Department of Entomology and to Piers Vigus for his thoughts on A. iris ab. iole.
References.
Note. All the articles by Ian Heslop written for the Entomological Journals that are listed below were later included as papers No 29, No 32, and No 33 in the Monograph (1964) Notes and Views of the Purple Emperor.
Frohawk F.W. (1938) Varieties of British Butterflies.
Goodson A.L. and Read D.K. (1969) Aberrational and Subspecific Forms of British Lepidoptera (unpublished work, British Museum of Natural History).
Harmer A.S. (2000) Variation in British Butterflies.
Heslop I.R.P (1960) A New Male Aberration of Apatura Iris (Linnaeus) (Lep. Nymphalidae) Entomologist Vol. 93. p.251.
Heslop I.R.P. (1961) Two New Aberrations of Apatura Iris Linnaeus. Entomologist's Record and Journal of Variation Vol 73 p. 58.
Heslop. I.R.P (1961) Aspects of Variation in Apatura Iris with the Description of one New Aberration. Entomologist's Record and Journal of Variation. Vol 73. p.73.
Heslop I.R.P., Hyde, G.E. and Stockley, R.E. (1964) Notes and Views of the Purple Emperor.
Heslop I.R.P. Diaries accessed 2016. Bristol City Museum.
Howarth T.G. (1973) South's British Butterflies.
Weir J.C. (2016) British Journal of Entomology. Intraspecific Taxonomy in the Lepidoptera.Vo1 29, part 3, p. 144.