M 34 British Columbia. 1922 



THE PTEBOPHOBID.E OF BRITISH COLUMBIA. 

 By E. H. Bi.ackmore, F.E.S. 



The recent publication of " The Pterophoridae of America, North of Mexico," by Drs. Barnes 

 and Lindsey (Cont. Lep. No. Amer., Vol. IV., No. 4, Aug. 1921) has so altered our conception 

 of many of the species, and also of some of the genera in this family, that I have thought it 

 advisable to write this short paper on the species occurring in British Columbia, and to bring 

 them up to date as regards correct determination and nomenclature. 



In the Check-list of British Columbia Lepidoptera published in 190G there are naturally a 

 number of misidentifications, many species to be eliminated, and there are also a considerable 

 number of additions. 



The species of this family are for the greater part very difficult to determine correctly, and 

 I wish to express my sincere thanks to Dr. A. W. Lindsey for his willing and kindly help in 

 determining a large number of specimens of doubtful and little-known species. I am also grateful 

 for his kind permission to make use of any part of the " Revision " that is applicable to our 

 British Columbia species. 



My thanks are also due to Messrs. Bryant, Cockle, Day, Hanham, and Ruhmann for the loan 

 of material, without which this paper would have been incomplete. 



The Pterophoridae can be distinguished primarily from any other family by the presence of 

 a series of black spine-like scales on the under-surface of the secondaries. 



In all the North American species, with one exception, the primaries are bifid and the 

 secondaries are trifid. The exception noted is Agdistis ameriuana B. & L., which has both fore 

 and hind wings entire. Two other exotic genera have the same characteristic, while another one 

 has the primaries quadrifid and a third has them trifid. 



The following general remarks on the family as a whole, taken from Genera Insectorum 

 Fasc, 100 (Pterophoridae by E. Meyrick), will prove of interest: — 



" Ovum more or less oval, smooth. Larva rather short, with more or less developed fascicles 

 of hairs ; usually feeding exposed on flowers or leaves, but sometimes internally in stems or 

 seed-vessels. Pupa sometimes hairy, attached by tail, or in a slight cocoon above ground. The 

 majority of those species whose food-plants are known are attached to the Composite?, which 

 are the most highly organized group of dicotyledonous plants, and this is especially true of the 

 two largest genera, Platyptilia and Pterophorus (Oidcetnatophorus) , where the association with 

 this order is very marked, probably nine-tenths of the species being attached to it. 



" The fore wings of the imago are very elongate, narrow, dilated posteriorly, and the legs arc 

 very long and unusually slender. The general structure seems adapted to secure extreme 

 lightness, thus enabling distribution to be effected by the wind without much effort on the 

 part of the insect; hence the species need and possess very little muscular power, ami are quite 

 unable to fly against even a moderate breeze. The method of distribution has been effective, 

 for the species have spread over the whole globe, including the principal oceanic islands; 

 though the wide distribution of some cosmopolitan species is due to artificial introduction with 

 the cultivated shrubs and trees on which the larva? feed. 



" Probably all the principal genera originated in Asia, which shows much the greatest 

 diversity of generic forms; the great specific development of Platyptilia and Pterophorus 

 (Oi,d<rmatophorus) in America would seem to be due to the large variety of abundant suitable 

 food-plants (Cornposita?) offered, whilst tbe relatively insignificant generic modification indicates 

 that the family did not find its way to America until long after its first origin. I infer, there- 

 fore, that it originated not only late in time, but at a period when Asia was comparatively isolated 

 from other regions by wide seas, and that on eventually gaining access to the other continents it 

 found them already well-stocked with a large leptdopterous fauna." 



In North America eleven genera are listed, embracing some 110 species, of which British 

 Columbia is represented by six genera with a total of 30 species, being slightly over 25 per cent. 

 of the whole. The synonyms of genera and species are not given in their entirety, but only 

 so far as they represent names previously given in former B.C. Check-lists. The descriptions of 

 genera are given with the venation omitted, but sufficient structural characters are given that 

 with the additional aid of the plate, no difficulty should be experienced in placing any specinlen 

 in its proper genus. The descriptions of species are not given in full detail, but all the essential 

 characters necessary for the identification of our British Columbia species are included. 



