462 BULLETIN 388 



ECONOMIC IMPORTANCE 



The poplar and willow borer is of greater economic importance than 

 has generally been supposed. It is a serious pest of practically all species 

 of willows, and where the beetle is abundant the damage done is extensive. 

 This is especially true of all varieties of ornamental willows. Also the 

 production of basket willows is greatly reduced and in many cases stopped 

 by the work of this insect. To many species of poplars it is very injurious, 

 especially when the trees are young (figs, in and 112). In many nurseries 

 the production of poplar stock has been discontinued owing to the prev- 

 alence and injuriousness of the pest. 



The willows (Salix species) and the poplars (Populus species) are 

 regarded generally as of not much value. However, many willows are 

 used extensively in landscape work, not only for their quality of rapid 

 growth but also for their beauty. Species native to this country line the 

 streams and encroach on the boundaries of lakes and ponds, serving a 

 very useful purpose as holders of the soil. The Carolina poplar, though 

 not looked upon with much favor as a shade tree, has been and is being 

 planted rather extensively in recently developed areas. This is especially 

 true in the Middle West, where the trees soon become suitable for lumber. 

 Extensive plantings made from forty to fifty years ago in the Middle 

 West, and also the great areas of cotton wood in the lower Mississippi 

 Valley, are now being lumbered. The product finds a ready sale as lum- 

 ber and commands a good price for excelsior. The Carolina poplar is used 

 also on sandy areas to keep the soil from being washed away. 



The balm-of-Gilead poplar, which is used generally as a shade tree, 

 is severely attacked by the borer. The branches serve excellently for the 

 development of the insect, and in sections where it is prevalent scarcely 

 a sound tree can be found. The branches, weakened by the larval bur- 

 rows, are broken off by high winds and ice storms, rendering the trees 

 unsightly. 



In Europe the beetle has proved a pest to many species of willows, 

 poplars, and alders. Many accounts are given of its destructive work, 

 and there is no doubt that it is proving even a worse pest in America. 



DISTRIBUTION 



The beetle, recorded as having first appeared in America in 1882 (Juelich, 

 1887), has not spread very rapidly. It is at present known to occur from 

 Maine west to Ontario and North Dakota and south to the District of 

 Columbia. Throughout this area it is restricted to certain localities, and 

 once introduced it does not spread rapidly unless carried by some agency. 

 It is reported by Fletcher and Gibson (1909) as occurring at Dundurn, 



