From Aberduna, Denbighshire this morning - f. conversaria of Mottled Beauty. I've sen lots of Mottled Beauty, but never this form. Does anyone have any idea how frequently it occurs?
Mottled Beauty f. conversaria
Re: Mottled Beauty f. conversaria
Hi Clive
I'm fairly sure I've had that form myself in Wales. Not a form I see that often in Cheshire, although I do have this photo of one from my garden back in 2009. Suspect it's more common in Wales than here in Cheshire. Suggest you ask the Denbighshire CMR.
Regards
Steve
I'm fairly sure I've had that form myself in Wales. Not a form I see that often in Cheshire, although I do have this photo of one from my garden back in 2009. Suspect it's more common in Wales than here in Cheshire. Suggest you ask the Denbighshire CMR.
Regards
Steve
Re: Mottled Beauty f. conversaria
Hi Steve
Thanks for the info on this. I’ll certainly email Justin Williams at some point, although I doubt if much data is available as I wonder how many recorders note the different forms of polymorphic species (as with the two versions of Riband Wave).
In relation to Riband Wave, I’m sure I’ve read something about the two forms occurring in different habitats, but I haven’t been able to track back to that. I did, however, find some stuff on the Mottled Beauty. In the Michael Majerus New Naturalist volume on moths he cites this species as an example of heterozygous advantage (where individuals carrying two different alleles of a gene (heterozygotes) are fitter (survive better) than those carrying two copies of the same allele (homozygotes). This is the same mechanism which has been cited to account for the persistence of Sickle-Cell disease (heterozygotes having better resistance to malaria) and Cystic Fibriosis (resistance to cholera) in human populations. Apparently in Mottled Beauty heterozygotes between the normal and conversaria alleles are more common than the frequencies of the homozygote forms would suggest.
Going back to E B Ford’s New Nats ‘Moths’ (pub 1955) I found that he stated that in “ Eastern Britain” the normal repandata form alone is found, but that the species is dimorphic between repandata and conversaria, which fits in with your observation.
Furthermore he said that it is possible to distinguish between individuals homozygous for conversaria, which have a white ground colour, and heterozygotes, which have a grey or brown ground colour. (On this basis mine from the other morning would appear to be a heterozygote.)
He described a study by Cockayne in Ross (NW Scotland) which found 480 repandata, 141 heterozygotes and only 5 homozygote conversaria.
He went on to suggest that collectors (as I guess all moth-ers were back then) could have a valuable role in collecting data about polymorphisms in different parts of the country – something which presumably remains true even today. Perhaps there are some PhD projects out there somewhere casting more light on this.
Cheers
Clive
Thanks for the info on this. I’ll certainly email Justin Williams at some point, although I doubt if much data is available as I wonder how many recorders note the different forms of polymorphic species (as with the two versions of Riband Wave).
In relation to Riband Wave, I’m sure I’ve read something about the two forms occurring in different habitats, but I haven’t been able to track back to that. I did, however, find some stuff on the Mottled Beauty. In the Michael Majerus New Naturalist volume on moths he cites this species as an example of heterozygous advantage (where individuals carrying two different alleles of a gene (heterozygotes) are fitter (survive better) than those carrying two copies of the same allele (homozygotes). This is the same mechanism which has been cited to account for the persistence of Sickle-Cell disease (heterozygotes having better resistance to malaria) and Cystic Fibriosis (resistance to cholera) in human populations. Apparently in Mottled Beauty heterozygotes between the normal and conversaria alleles are more common than the frequencies of the homozygote forms would suggest.
Going back to E B Ford’s New Nats ‘Moths’ (pub 1955) I found that he stated that in “ Eastern Britain” the normal repandata form alone is found, but that the species is dimorphic between repandata and conversaria, which fits in with your observation.
Furthermore he said that it is possible to distinguish between individuals homozygous for conversaria, which have a white ground colour, and heterozygotes, which have a grey or brown ground colour. (On this basis mine from the other morning would appear to be a heterozygote.)
He described a study by Cockayne in Ross (NW Scotland) which found 480 repandata, 141 heterozygotes and only 5 homozygote conversaria.
He went on to suggest that collectors (as I guess all moth-ers were back then) could have a valuable role in collecting data about polymorphisms in different parts of the country – something which presumably remains true even today. Perhaps there are some PhD projects out there somewhere casting more light on this.
Cheers
Clive
Re: Mottled Beauty f. conversaria
As a footnote to this, another f. conversata a couple of nights ago makes me wonder if this form is adapted to resting on very fissured bark. This image hints at it, with the moth in a self-chosen resting position, having been un-potted onto a willow trunk.