INJURIOUS INSECTS OF 1904. 



185 



in May from Redwood County. It feeds upon the foliage of willow 

 and poplar, and sometimes succeeds in almost defoliating these 

 trees in windbreaks. Spraying with Paris green or any other 

 arsenite will effectually stop their work. Fig. 167 illustrates the 

 great variations in the markings of this species. 



Fig. 167. — The Poplar Borer; variations from type. From Riley. 



GALL iAIAKERS ON THE BOX ELDER, SOFT MAPLE AND 



BASSWOOD. 



The accompanying illustration, Fig. 168, is from a photograph 

 of box elder leaves, which exhibit a gall made by a tiny two-winged 

 fly. For two years or more box elders, always attractive to many 



^^: 



Fig. 168. — Galls on leaves of Box Elder. A. G. Ruggles. 



