i8 



tical to depend upon this means alone in combating this insect. 

 Usually the willows are too large before time for the third treatment 

 to spray to the best advantage and hence the machine should be 

 brought into use for a short time if necessary. On newly planted 

 fields, however, spraying will be found of special advantage in 

 keeping ofi" the insects while the willows are getting a start and 

 before they are high enough for the machines. 



IMPORTANCE OF A UNITED EFFORT OF THE WILLOW GROWERS. 



Insects which migrate as readilj' as the cottonwood leaf-beetle 

 will quickly spread over a community where their food plant is 

 extensively grown. The adults of this species fly readily and 

 probably for quite long distances. In the fields about Syracuse, 

 they literally swarm upon the willows, coming from all directions, 

 especially from neglected fields, which of late years are becoming 

 common in this community. A neglected field of willows means 

 that the beetles will breed there unmolested and as food becomes 

 short or as migratory instincts dictate, will seek other fields in the 

 vicinity. Several illustrations of this kind came to the writer's 

 notice at Liverpool. Willow growers whose fields were in the 

 vicinity of neglected fields suffered greater loss from injury to the 

 willows, or were put to greater expense in combating the insect 

 than were those whose neighbors united with them in an effort to 

 check the pest. 



