stray Notes on the Variation and Distribution of 

 Boarmia repandata in Britain. 



By Robert Adkin, F.E.S. Read April Zth, 1909, 



There are few species that have a wider range of distribution in 

 Britain, or that show a greater tendency to variation, than Boarmia 

 repandata. It is a common species, and there is therefore no 

 great difficulty in obtaining material, but I fear that even the some- 

 what extensive series used to illustrate these notes, occupying as it 

 does the whole of two ordinary cabinet drawers, and consisting of 

 specimens obtained from localities representing the greater portion 

 of the British Islands, is yet hardly sufficient to fully exhibit the 

 vast range of variation that obtains in the species. 



The main features of its coloration are varying shades of grey and 

 brown, and it is to the predominance of the one or the other and 

 their arrangement as either bands, patches, or speckling, that the 

 variation is chiefly- due. 



The natural restijig-place of the moth is the trunks of trees, but in 

 some of the situations where it occurs tree-trunks are not available, 

 and it then has to find some other situation, as, for instance, rocks, 

 where it may assume its natural position of rest with outspread 

 wings. It has been suggested that in such cases its colour assimilates 

 with the object on which it rests, but although this suggestion appears 

 to hold good in regard to some of its more specialised forms, there 

 are others that can hardly be held to support it. 



Whether its range extends to our northernmost islands is a 

 question that is open to considerable doubt. Barrett (" Lep. Brit. 

 Islands," vol. vii, p. 214), distinctly refers to a form from Shetland, 

 and one is not inclined to treat the writings of so careful an observer 

 lightly ; but my inquiries of those who have worked these islands, 

 and probably know them as well or better than anybody else, elicit 

 the information that they have never met with the species either in 

 Shetland or Orkney, and they express the opinion that, at any rate 

 so far as the former is concerned, it is most unlikely that it occurs 

 there. But whether it occurs in these northern islands or not, it is 

 a common species in the western islands, where, in the Isle of Lewis, 

 Outer Hebrides, a very distinct form occurs. In it the brown tones 

 are practically absent, leaving a mottled-grey insect, in size somewhat 

 smaller than the average B. repandata, and of slighter build. It 

 was, I believe, first brought from Lewis by Harper, when he was 

 collecting for Meek in 1881, and was described and figured by 

 Jenner Weir under the name of ab. sodorensium (" Entomologist,'' 



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