246 MAINE) AGRICUIvTURAI, e:XPE;RIMENT STATION, I9II. 



nijficant so far as the alder itself is concerned. However, as 

 the cultivated cut leaved maple as well as the native variety of 

 the same species (Acer saccharium L dasycarpum Ehrh) is in 

 Maine dependent for its infestation on the fall migrants from 

 the alder, treasured ornamental maples could be protected by 

 destroying the alder in the vicinity. The practibility of this 

 course would depend on the quantity of the neighboring alders. 

 In Minnesota (Washburn 1903) and elsewhere where the 

 infestation of alder clumps themselves is regretted, remedial 

 measures can often be applied directly to the alder. As the 

 alder is a permanent host of this species, one thorough treat- 

 ment should be sufificient for a year at least. The landscape 

 gardener would perhaps save himself trouble if he withheld 

 susceptible maples from the vicinity of native alders. 



