40 B. C. EXTOMOLOGK'AL SOCIETY 



Two rows of black currants in a block adjacent to heavily infested 

 English elm were treated with naphthalene compound (naphthalene and 

 wood ashes) just as the migrants were leaving the elms. The treated 

 rows kept entirely free from root infestations for two weeks. A few 

 migrants were found in the soil and an occasional root form, but always 

 dead and discolored. The untreated rows showed numbers of migrants, 

 and infection of the roots soon became general. Eventually, when the 

 effect of the light dose of naphthalene disappeared, the later migrants 

 infected the roots of the treated rows. 



From the result of these experiments it would appear that a heavier 

 dressing of crude naphthalene — six handfuls to each bush hoed in to a 

 depth of 2-3 inches — would be satisfactory. 



PRELIMINARY LIST OF APHIDIDAE OF BRITISH COLUMBIA 



1)Y K. Glendenning 



Callipternini (Tribe). 



Phyllaphis fagi (L.). On copper beech. Agassiz. The copiously floccu- 



lent lice are frequent all summer on the undersides of the leaves. 

 Chromaphis juglandicola (Kalt). On walnut. Agassiz. 



Therioaphis tiliae (L.). Common on lime and linden, Tilia sp. on Experi- 

 mental Farm, Agassiz. A very distinct species. Body with black 

 bars and wing veins heavily bordered with black. 



Euceraphis gillettei (D'son). A large free-flj-ing species, using Alnus 

 oregona as a primary host ; also found on Birch. 



Euceraphis betulae (Koch). A similar species frequent on Birch. 



Myzocallis querci (Kalt). A small green species on introduced oak — 

 Agassiz and Westminster. 



Drepanosiphum platanoides (Sdirank). A large active species very 

 common on Acer pseudo-platanus in the Lower Eraser Valley. Very 

 objectionable from copious excretion of honey dew, on which a black 

 fungus grows. 



Chaitophorus viminalis (Monell). Frequent on native cottonwood (P. 

 trichocarpa), rendering the leaves very sticky. 



Periphyllus americanus (Baker). A dark red species on Acer circinatum 



— dimorphic— .tiding over the dry weather thus. 

 Neothomasia populicola (Thomas). Frequent on petioles of cottonwood 



leaves. Apterae yellowish with a black Y on back. 

 Melanoxantherium populifoliae (Fitch). On twigs of Salix sps. 



