22 BULLETIN" 1469, IT. S. DEPARTMENT. OF AGRICULTURE 
SUMMARY 
The satin moth, a common European insect, was first discovered in 
the United States near Boston, Mass., in June, 1920. In July of the 
same year it was found near Vancouver, British Columbia, and was 
reported in the State of Washington in 1922. 
Its principal food plants in Europe and on this continent have 
been the poplars and willows, although records have been made prov- 
ing that it can develop when fed for a part of the time on scrub oak. 
Spraying with arsenate of lead has. proved that when properly 
applied it will control this insect. Spraying in the spring is recom- 
mended, and the addition of fish oil or linseed oil to the spray mix- 
ture is strongly advised. 
Several of the beneficial insects which have been successfully estab- 
lished as enemies of the gipsy moth and the brown-tail moth, and 
some native parasites, have been recorded as attacking this recently 
introduced pest. The parasitism of the satin moth in New England 
by the imported parasite C ompsilura concinnata and by two native 
tachinids in British Columbia has been especially noticeable and has 
prevented many larvae from maturing. 
Long-distance spread of the satin moth is being prevented as a 
result of the enforcement of the quarantine regulations. 
Natural enemies are retarding to some extent the increase of this 
insect. 
Control work in the New England States is performed by indi- 
viduals or by the local authorities, and although many trees are 
sprayed annually with excellent results, there are heavily infested 
sections which receive no treatment at all. This has resulted in the 
rapid increase of the insect during the last five years and its contin- 
ued spread to uninfested towns and States. 
The States concerned and the local authorities in districts infested 
or threatened with infestation should take vigorous measures to con- 
trol this insect, and the Bureau of Entomology will cooperate as far 
as possible by furnishing the latest information concerning this pest 
and the proper methods of control. 
All citizens, and particularly visitors or tourists, can assist by 
refraining from transporting willows or poplars from the infested 
area. 
