Melanism in Butterflies (1 Viewer)

[the bird]

Firstly, apologises that I have no photos - they did not come out. Also I can't remember any details of the butterfly I was just asking in a general kind of way.

Whilee I was in Scotland - Glen Lyon to be more precise, me and my girlfriend were sunning our selves by a river I noticed a couple of very small dark brown (if not black) butterflies. I remember thinking at the time are they melanic common blues because of some of the slight markings (designs) on their wings. I also thought they were possibly melanic blues of some variety, since size is affected by melanism.


Am I off my head thinking this or is melanism quite common in butterflies at high altitudes and colder areas.

Or is it not melanism at all (I definately couldn't find them in my trusty David Attenborough butterflies & moths field guide).

If anybody has got any inforation or any ideas it would be greatly appreciated!!!

The Bird - John :eek!:

 

[harry eales]

Firstly, apologises that I have no photos - they did not come out. Also I can't remember any details of the butterfly I was just asking in a general kind of way.

Whilee I was in Scotland - Glen Lyon to be more precise, me and my girlfriend were sunning our selves by a river I noticed a couple of very small dark brown (if not black) butterflies. I remember thinking at the time are they melanic common blues because of some of the slight markings (designs) on their wings. I also thought they were possibly melanic blues of some variety, since size is affected by melanism.


Am I off my head thinking this or is melanism quite common in butterflies at high altitudes and colder areas.

Or is it not melanism at all (I definately couldn't find them in my trusty David Attenborough butterflies & moths field guide).

If anybody has got any inforation or any ideas it would be greatly appreciated!!!

The Bird - John :eek!:

Hello John,

It's likely that what you saw was a fairly common day flying moth known as The Chimney Sweep. Odezia atrata (Linnaeus, 1758)
They are common in damp places, especially where there is a lush growth of grasses.

This species is frequently reported as a sighting of The Small Blue butterfly, and it drives County recorders 'nuts' as they are, very butterfly like, in appearance, have sooty black wings fringed with white hairs.

Melanism does occur in butterflies, but more often as not, as a freak variation from the standard form, this can be genetic or phenetic in origine. Altitude has little, if anything, to do with melanism or melanistic tendencies. It should be said that some species of moth get darker the further north you travel but this is geographic variation rather then melanism.

It would be of help if you could give a date you saw this insect species.

Harry

 

[the bird]

Hello John,

It's likely that what you saw was a fairly common day flying moth known as The Chimney Sweep. Odezia atrata (Linnaeus, 1758)
They are common in damp places, especially where there is a lush growth of grasses.

This species is frequently reported as a sighting of The Small Blue butterfly, and it drives County recorders 'nuts' as they are, very butterfly like, in appearance, have sooty black wings fringed with white hairs.

Melanism does occur in butterflies, but more often as not, as a freak variation from the standard form, this can be genetic or phenetic in origine. Altitude has little, if anything, to do with melanism or melanistic tendencies. It should be said that some species of moth get darker the further north you travel but this is geographic variation rather then melanism.

It would be of help if you could give a date you saw this insect species.

Harry

Hi Harry

I've read your comments, but I can assure you these were definately butterflies. I'm used to seeing day flying moths, and these little winged creatures were butterflies.

Also isn't geographical variation can be classed the same as melanism, for example if you take the lady bird - the more common variety of seven spotted lady bird is the one we are all familiar with - red back ground and black spots, however, with higher altitudes and the further north you go the seven spot lady bird with black background and red spots become more common (bigger proportion of the population). Also the size decreases the further north you go.

This is why I thought there might have been a variation in whatever butterfly sp. this was.


More information required I'm a thinking !!!!!

John- The Bird

 

[harry eales]

Hi Harry

I've read your comments, but I can assure you these were definately butterflies. I'm used to seeing day flying moths, and these little winged creatures were butterflies.

Also isn't geographical variation can be classed the same as melanism, for example if you take the lady bird - the more common variety of seven spotted lady bird is the one we are all familiar with - red back ground and black spots, however, with higher altitudes and the further north you go the seven spot lady bird with black background and red spots become more common (bigger proportion of the population). Also the size decreases the further north you go.

This is why I thought there might have been a variation in whatever butterfly sp. this was.


More information required I'm a thinking !!!!!

John- The Bird

Hello John,
The only smallish brown or dark coloured butterflies you will find in scotland are:-

Small Heath.
Large Heath.
Mountain Ringlet.
Female Common Blue.
Brown Argus
Small Blue
Dingy Skipper
Chequered Skipper
Purple Hairstreak

Larger Brown or mainly brown Scottish butterflies are:-

Meadow Brown,
Ringlet,
Grayling,
Small Pearl-bordered Fritillary,
Pearl-bordered Fritillary,
Dark Green Fritillary,
Marsh Fritillary,
Speckled Wood.
Scotch Argus.

Of this latter group only a very freshly emerged Ringlet looks black from a few yards away.

It would help if you could describe the habitat, the altitude and give the date they were seen. This could help eliminate several species.

Scottish Small & Large Heath are lighter than their English counterparts.

The Small Mountain Ringlet differs little from the English form, and is seldom found below 500m, but it's a possibility in Glen Lyon.

Small Blue is confined mainly to the coastal areas.

There are no records for the Dingy Skipper in that area,

It is vaguely possible that Checkered Skipper is present in Glen Lyon it's certainly in the general area of Fort William.

Brown Argus is only to be found in eastern Scotland.

Purple Hairstreak is seldom seen away from the upper branches of Oak and is very unlikely to be seen in grasses at a river side, and when in flight it looks silvery grey rather than dark.

So it boils down to possibly Small Mountain Ringlet or female Common Blue as possible contenders.

If what you saw was Common Blue sized then this alone, would eliminate the entire second group.

Geographical variation and melanism are two entirely different things and what may apply to Ladybirds may not necessarily apply to Butterflies indeed it can even be the reverse. E.G. The darkest and most heavily marked Large Heath butterflies are to be found in the south of their range and the lightest and most lightly marked at the very north of their range.

Harry

 

[the bird]

Thanks for your input -

I can tell you what I remember -


The area was by a medium / fast flowing river.

There were silver birches and other lightly foliaged trees in the surrounding area.

The area where they were feeding was covered in wild pea sp. and clovers.

It was very hot and sunny day.

They flew close to the ground and it was, if I remember rightly lunchtime to very early afternoon - so me thinks Purple Hairstreak it was not, anyway I have seen hairstreaks and these definately weren't them.

And Harry this really is where I get confused - if the little winged creatures were female common blues - they'd be very dark and also where were the males???


Harry I must tell you I was probably as close as a few centimetres away from these little things. I do remember several very small white spots on underwing - not like Ringlet spots.

Altitude wasn't particularly high we were in the valley bottom, I can probably find out more if you need it. Glen Lyon is based near Killin and Pitlochrie - central / north scotland.

Time - Late June

It was definately common blue sizeish - a bit smaller if be truth be told. However, that maybe just because they were black and black does give the impression of being smaller.

I hope this will help a little bit.


John

 

[CornishExile]

Firstly, apologises that I have no photos - they did not come out. Also I can't remember any details of the butterfly I was just asking in a general kind of way.

Whilee I was in Scotland - Glen Lyon to be more precise, me and my girlfriend were sunning our selves by a river I noticed a couple of very small dark brown (if not black) butterflies. I remember thinking at the time are they melanic common blues because of some of the slight markings (designs) on their wings. I also thought they were possibly melanic blues of some variety, since size is affected by melanism.


Am I off my head thinking this or is melanism quite common in butterflies at high altitudes and colder areas.

Or is it not melanism at all (I definately couldn't find them in my trusty David Attenborough butterflies & moths field guide).

If anybody has got any inforation or any ideas it would be greatly appreciated!!!

The Bird - John :eek!:

Completely as an aside from the identification aspect of this thread (I bow to Harry's undoubted expertise), I think I'm right in suggesting that melanism in butterflies is largely stimulated by seasonal environmental extremes, particularly high temperatures during the pupal stage of the life cycle. I seem to recall a higher than usual amount of melanistic variations occured during the hot summer of 1976 for example. It's possible (though with a high attached mortality rate) to induce this when breeding butterflies at home, particularly straightforward with Small Tortoiseshells - I'd have to dig out my notes from when I was working with this many years ago to find precise details of the temperatures, timing, and degrees of exposure involved, if anyone's interested.

Jon

 

[the bird]

Completely as an aside from the identification aspect of this thread (I bow to Harry's undoubted expertise), I think I'm right in suggesting that melanism in butterflies is largely stimulated by seasonal environmental extremes, particularly high temperatures during the pupal stage of the life cycle. I seem to recall a higher than usual amount of melanistic variations occured during the hot summer of 1976 for example. It's possible (though with a high attached mortality rate) to induce this when breeding butterflies at home, particularly straightforward with Small Tortoiseshells - I'd have to dig out my notes from when I was working with this many years ago to find precise details of the temperatures, timing, and degrees of exposure involved, if anyone's interested.

Jon

Hiya Jon


As you have read the thread I am currently very confused with a butterfly sp. I saw while on holiday a couple of years ago. And since I studied melanism in lady birds of the UK and the causes and reasons of melanism in other species such as crows etc, I was just wondering about butterflies since this would explain what I saw down to a tee.

John - The Bird

If you could forward me any info you have on melanism that you have made I would love to read it.

e-mail - [email protected]

greatly appreciated

 

[harry eales]

Thanks for your input -

I can tell you what I remember -


The area was by a medium / fast flowing river.

There were silver birches and other lightly foliaged trees in the surrounding area.
The area where they were feeding was covered in wild pea sp. and clovers.
It was very hot and sunny day.

They flew close to the ground and it was, if I remember rightly lunchtime to very early afternoon - so me thinks Purple Hairstreak it was not, anyway I have seen hairstreaks and these definately weren't them.

And Harry this really is where I get confused - if the little winged creatures were female common blues - they'd be very dark and also where were the males???

Harry I must tell you I was probably as close as a few centimetres away from these little things. I do remember several very small white spots on underwing - not like Ringlet spots.

Altitude wasn't particularly high we were in the valley bottom, I can probably find out more if you need it. Glen Lyon is based near Killin and Pitlochrie - central / north scotland.

Time - Late June

It was definately common blue sizeish - a bit smaller if be truth be told. However, that maybe just because they were black and black does give the impression of being smaller.

I hope this will help a little bit.
John

Hello John,

I have to admit I'm getting a bit 'stumped' here. We seem to have eliminated just about every possibility, either by known distribution or size. If they had been female Common Blue's, you are correct, there should have been males about, and they're a lot more visible than the females. In addition Scottish female Common Blues to tend to have more blue on their upperwing surfaces than English specimens, so this really puts this species out of the frame as well.

That particular area of Scotland had been well worked by entomologists for the best part of 150 years so the chances of you having discovered a previously unknown species of butterfly are extreamly slim. The habitat you describe doesn't offer many additional clues either.

Which brings me back to the Chimney-sweeper moth I suggested in my first reply to your post. It does fly in that area, the time of year is correct for it to be on the wing, the size is right, the larval foodplants are common in that area, and it likes to fly in bright sunshine. Lastly it looks very butterfly like.
See:-
http://www.cornwallwildlifetrust.org.uk/images/photoalbums/moths/moth0009_jpg.htm

I have not been able to find a photo of the underside, nor a description of the underside in any of my moth books, or do I have immediate access to a specimen to examine the underside to see what it looks like.

(Can any BF member help out here?)

Looking at Jon's post ref. temperature effecting colour, especially in darkening to colour of specimens. It is true, that in very hot years, a good many varieties of butterfly are produced where their scale colours are altered the pupae being exposed to higher temperatures or extreams of sunlight.

The well known 'Merrifield Experiments' on inducing colour change by treating newly formed pupae to artificial temperature changes for short periods, prove
that vary dark specimens of a number of butterfly species can be produced.

This effect, when it takes place naturally in 'The Wild' in years when temperatures are much higher than usual is known as 'phenetic' (the s`pecimens being the result of the environmental conditions pertaining at the time).

In the Laboratory it is mainly the Vanessid butterflies that have been used as experimental material, although several amateur experimenters have gone on to other butterfly families. Such experiments are very time consuming and the temperatures involved can be critical and short lived if the pupae is to survive. The so called 'Blind Peacock' butterflies can be produced using these heat treatment methods.

If my memory serves me correctly, in 1993, the year you saw these butterflies in Scotland, was not unusual for high temperatures, so it is unlikely that what you saw, were variations of a species that were subject to unusually high temperature conditions.

Unless someone else can come up with a viable alternative as to what species of lepidoptera you saw, it looks like your going to have to back again this year to the same place for your holidays, and get some good pictures.

Sorry, but I don't think I can be of more help.

Harry

 

[CornishExile]

Which brings me back to the Chimney-sweeper moth I suggested in my first reply to your post. It does fly in that area, the time of year is correct for it to be on the wing, the size is right, the larval foodplants are common in that area, and it likes to fly in bright sunshine. Lastly it looks very butterfly like.
See:-
http://www.cornwallwildlifetrust.org.uk/images/photoalbums/moths/moth0009_jpg.htm

I have not been able to find a photo of the underside, nor a description of the underside in any of my moth books, or do I have immediate access to a specimen to examine the underside to see what it looks like.

(Can any BF member help out here?)

Harry

This is the best I can find at short notice. Not much help I suspect.

Underside of chimney-sweeper

Jon

 

[the bird]

Hello John,

I have to admit I'm getting a bit 'stumped' here. We seem to have eliminated just about every possibility, either by known distribution or size. If they had been female Common Blue's, you are correct, there should have been males about, and they're a lot more visible than the females. In addition Scottish female Common Blues to tend to have more blue on their upperwing surfaces than English specimens, so this really puts this species out of the frame as well.

That particular area of Scotland had been well worked by entomologists for the best part of 150 years so the chances of you having discovered a previously unknown species of butterfly are extreamly slim. The habitat you describe doesn't offer many additional clues either.

Which brings me back to the Chimney-sweeper moth I suggested in my first reply to your post. It does fly in that area, the time of year is correct for it to be on the wing, the size is right, the larval foodplants are common in that area, and it likes to fly in bright sunshine. Lastly it looks very butterfly like.
See:-
http://www.cornwallwildlifetrust.org.uk/images/photoalbums/moths/moth0009_jpg.htm

I have not been able to find a photo of the underside, nor a description of the underside in any of my moth books, or do I have immediate access to a specimen to examine the underside to see what it looks like.

(Can any BF member help out here?)

Looking at Jon's post ref. temperature effecting colour, especially in darkening to colour of specimens. It is true, that in very hot years, a good many varieties of butterfly are produced where their scale colours are altered the pupae being exposed to higher temperatures or extreams of sunlight.

The well known 'Merrifield Experiments' on inducing colour change by treating newly formed pupae to artificial temperature changes for short periods, prove
that vary dark specimens of a number of butterfly species can be produced.

This effect, when it takes place naturally in 'The Wild' in years when temperatures are much higher than usual is known as 'phenetic' (the s`pecimens being the result of the environmental conditions pertaining at the time).

In the Laboratory it is mainly the Vanessid butterflies that have been used as experimental material, although several amateur experimenters have gone on to other butterfly families. Such experiments are very time consuming and the temperatures involved can be critical and short lived if the pupae is to survive. The so called 'Blind Peacock' butterflies can be produced using these heat treatment methods.

If my memory serves me correctly, in 1993, the year you saw these butterflies in Scotland, was not unusual for high temperatures, so it is unlikely that what you saw, were variations of a species that were subject to unusually high temperature conditions.

Unless someone else can come up with a viable alternative as to what species of lepidoptera you saw, it looks like your going to have to back again this year to the same place for your holidays, and get some good pictures.

Sorry, but I don't think I can be of more help.

Harry

Harry


Looked at your link to cornwall wildlife and at the picture this does resemble the little odd jobie. The white edging is definate!!!! I think you might well have hit the nail on the head.... had search on the net can't find any more pictures....... do you know where I can see more so I can definately put my mind to rest!!!!

I know your on to something here .... coz I'm getting really excited and I'm typing like a beast!!!


John - The Bird

 

[harry eales]

Harry

Looked at your link to cornwall wildlife and at the picture this does resemble the little odd jobie. The white edging is definate!!!! I think you might well have hit the nail on the head.... had search on the net can't find any more pictures....... do you know where I can see more so I can definately put my mind to rest!!!!

I know your on to something here .... coz I'm getting really excited and I'm typing like a beast!!!

John - The Bird

Hello John,
I'm glad were getting somewhere at last. lol. The Chimney-sweeper is a common moth with a very wide distribution, but it is local. It likes damp field edges, country lanes, I have even seen it along forest rides through pine plantations. Searching for the foodplants will also help you find it.

Your easiest way of locating it, near to your home, would be to get in touch with your County Recorder for Moths. He/She will no doubt, have a large number of localities you could look at, and, as it is not an endangered or a rare species, I very much doubt if the info would be refused. It flies in June and July and is most easily seen on a hot sunny day.

It really is sooty black when freshly emerged, but this does fade to a dark brown after a few days. Good Hunting.

Harry.

 

[the bird]

Hello John,
I'm glad were getting somewhere at last. lol. The Chimney-sweeper is a common moth with a very wide distribution, but it is local. It likes damp field edges, country lanes, I have even seen it along forest rides through pine plantations. Searching for the foodplants will also help you find it.

Your easiest way of locating it, near to your home, would be to get in touch with your County Recorder for Moths. He/She will no doubt, have a large number of localities you could look at, and, as it is not an endangered or a rare species, I very much doubt if the info would be refused. It flies in June and July and is most easily seen on a hot sunny day.

It really is sooty black when freshly emerged, but this does fade to a dark brown after a few days. Good Hunting.

Harry.

Cheers Harry you are not only a life saver you are also a mind saver!!!! :clap:

Its been niggling me since I saw them!!!!!! o

I LOVE YOU :flowers:

John - The Bird B

 

[harry eales]

This is the best I can find at short notice. Not much help I suspect.

Underside of chimney-sweeper

Jon

Hello Jon,

Unfortunately your underside picture didn't help, I even tried running it through Photoshop7 and lightening it, but no markings showed up. Thanks for trying though.

Harry

 

[Gary75]

Firstly, apologises that I have no photos - they did not come out. Also I can't remember any details of the butterfly I was just asking in a general kind of way.

Whilee I was in Scotland - Glen Lyon to be more precise, me and my girlfriend were sunning our selves by a river I noticed a couple of very small dark brown (if not black) butterflies. I remember thinking at the time are they melanic common blues because of some of the slight markings (designs) on their wings. I also thought they were possibly melanic blues of some variety, since size is affected by melanism.


Am I off my head thinking this or is melanism quite common in butterflies at high altitudes and colder areas.

Or is it not melanism at all (I definately couldn't find them in my trusty David Attenborough butterflies & moths field guide).

If anybody has got any inforation or any ideas it would be greatly appreciated!!!

The Bird - John :eek!:

I've just seen this, twenty years late, but found it interesting. My initial reaction was, like the first respondent, that the insects were Chimney Sweeper moths, which do have flight characteristics not unlike a butterfly's. However, the mention of white spots on the underside brought an alternative ID to mind. The Northern Brown Argus butterfly (Aricia, artaxerxes, which I've seen in Perthshire) takes the place of southern England's Brown Argus (Aricia agestis). Both species are almost the size of a Common Blue, and fly like one. The upperside is a dark chocolate colour. The underside of the latter hass white spots, pupilled with black dots. In the Scottish artaxerxes, the central dots are absent, leaving...white spots! QED, I think?