A RECENTLY INTRODUCED PEST 6 
NORTH AMERICAN DISTRIBUTION 
IN CANADA 
In July, 1920, J. D. Tothill found caterpillars of the satin moth 
defoliating poplar trees in New Westminster, British Columbia. 
Anxiety was felt by the Canadian authorities when this insect was 
discovered within their territory, its close relation to the gipsy moth 
(Porthetria dispar L.) and the brown-tail moth 2 (Nygmia phae- 
orrhoea Donovan) placing it in a group of notoriously injurious 
insects. 
K. Glendenning, of the entomological branch, Department of 
Agriculture, Dominion of Canada, has conducted investigations on 
this insect, the results of which have been published by the Dominion 
Department of Agriculture. 3 Lombardy poplar trees on the grounds 
of Columbia College, at New Westminster, were found to be heavily 
infested by the satin moth in July, 1920, and during the summer the 
insect spread to most of the white and Lombardy poplar trees in 
the city. A few moths were found in a village about 2 miles east 
of the city. The following year several infestations were located, 
the worst one being at Vancouver, British Columbia, which was so 
severe as to indicate that it was the original infestation and that the 
infestations at New Westminster and other places had originated 
from Vancouver. At the time of the preparation of the report the 
infested area included about 50 square miles on the mainland of 
British Columbia, with several infestations on Vancouver Island. 
In the summer of 1923 the senior author visited some of the in- 
fested area in New Westminster and noted partial to complete 
defoliation of poplar and willow trees. 
IN THE STATE OF WASHINGTON 
The first record of the satin moth in the State of Washington 4 
was made at Bellingham in 1922 by W. E. Longley. The insect was 
first seen on a nearly defoliated row of Lombardy poplars. Later in 
the season it was discovered in several other places. The specimens 
were identified at the Dominion Museum at Victoria, British 
Columbia. 
Since that time considerable scouting has been done throughout 
the western part of the State of Washington, under the direction of 
A. G. Webb, plant quarantine inspector of the Federal Horticultural 
Board, who has charge of the port of Seattle. The results of this 
work indicated that the insect had become established in many local- 
ities where poplar and willow trees are present, distributed through- 
out most of the counties from the international line south to Seattle. 
As a result of this work the Federal quarantine was extended in the 
2 In American publications the brown-tail moth has been known since its establishment 
in tbe United States as Euproctis chrysorrhoea L. It is regrettable that the use of a 
name which has been employed so long and is so well understood should have to be dis- 
continued. However, evidence has been presented to prove clearly that E. chrysorrhoea 
is the name of another common European insect. Barnes, W., and Benjamin, F. H. 
ON THE CORRECT NAME FOR THE BROWN-TAIL MOTH. Ent. SOC Wash. PrOC. 26 : 213. 
3 Glendenning, R. the satin moth in British Columbia. Canada Dept. Agr. 
Pamphlet 50, New Series, 14 pp., 1924. 
4 Acknowledgment is gladly made here of the kindness of E. R. Sasscer, of the Federal 
Horticultural Board, in allowing the writers to refer to a report by A. G. Webb, asso- 
ciate plant quarantine inspector, in regard to the satin-moth situation in the State of 
Washington. 
