New York Agricultural Experiment Station. 337 



SHOULD SPRAYING ALONE BE DEPENDED UPON IN COMBATING THIS 



INSECT ? 



Although the results in the above experiments are very gratify- 

 ing in favor of spraying, in many seasons it will be found imprac- 

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

 Usually the willows are too large before time for the third treat- 

 ment 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 ad- 

 vantage in keeping off 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 readily 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. 



RECOMMENDATIONS. 



Begin spraying early in the season. Make the first application 

 before the beetles become numerous and follow it by one or two, 

 more a week or 10 days apart. 



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