SUMMARY 01-' II^SECT COXDITIOXS DURING 1921. 



47 



area the infestation can be considered as only slight. Very little 

 territory was added this jesii to that infested in 1920. Rock- 

 Jand township is the first township in Plymouth County to be in- 

 fested. Needham and Millis were added to the two towns already 

 infested in Norfolk County. HoUiston is added to the infested 

 towns in Middlesex County, and Rye is added to the towns infested in 

 Eockingham County, N. H. 

 Reports of this 



insect were re- 

 ceived through 

 the office of blister 

 rust control, Bu- 

 reau of Plant In- 

 dustry, from 

 Westminster, 

 British Colum- 

 bia, where the 

 moth was re- 

 ported as estab- 

 lished in a park 

 where it was 

 thought to have 

 been introduced 

 on soldiers' equip - 

 ment from the 

 Gallipoli Penin- 

 sula, as the sol- 

 diers were quar- 

 tered in this park 

 on their return 

 from the Darda- 

 nelles. It is reported that 80 per cent of the moths in Canada were 

 killed during the winter by a parasite. 



Arthur Gibson, Dominion entomologist, says : 



During the past summer the outbreak of this insect in British Columbia 

 extended to Vancouver Island. At the present time the insect is permanently- 

 established on the mainland adjacent to Vancouver and New Westminster and 

 on Vancouver Island at Duncans. 



This insect threatens poplars and possibly willows over the whole 

 area of its distribution. So far, however, only the poplars planted 

 for shade have suffered severely. The species has attacked Lom- 

 bardy, Carolina, and Balm of Gilead, and undoubtedly will attack 

 practically all of the species of poplar. The favored species usually 

 occur singly or in small plantings over the area infested by this in- 



FiG. 26. — Geographical distribution of the satin moth in the 

 United States : Solid-colored area, known to have been in- 

 fested in 1920 ; uncolored named towns, infested in 1921. 



