
M 34 British CoLtuMBIA. | bw ; 1922 


THE PTEROPHORIDAS. OF BRITISH COLUMBIA. 
By DB. HW. Biackmonrg, F.E.S. 
q The recent publication of “ The Pterophoridre 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 haye 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 1906 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 weuld have been incomplete. 
The Pterophoridse 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 americana 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 (Pterophoridze 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 (Oidematophorus), 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 are 
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, and 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 laryre 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 
(Oidamatophorus) in America would seem to be due to the large variety of abundant suitable 
food-plants (Composite) offered, whilst the 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 lepidopterous fauna.” 
In North America eleyen genera are listed, embracing some 116 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 specimen 
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. 


