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abstract. 



UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 480 



J^"-* Contribution from the Bureau of Entomology ^^!Lf\ 



J&&* < &*TU L. O. HOWARD, Chief f&Z^^&U 



Washington, D. C. 



June 30, 1917 



SOLID-STREAM SPRAYING AGAINST THE GIPSY 

 MOTH AND THE BROWN-TAIL MOTH IN NEW 

 ENGLAND. 



By L. H. Woethley, Agent in Charge of Scouting and Extermination Work, 

 Gipsy and Brown-Tail Moth Investigations. 



CONTENTS. 



Page. 



Introduction 1 



History 1 



Description of apparatus 3 



The engine 4 



The hose 4 



Nozzles 5 



Motor-truck sprayer 6 



Poison 7 



Mixing poison 8 



Agitation 8 



Amount of solution to be used. 8 



Pressures 9 



Experiment to determine the distribution of 



poison on foliage 10 



Shade-tree spraying ll 



Woodland spraying 12 



Winter care of spraying machines and equip- 

 ment 13 



Summary h 



INTRODUCTION. 



In nearly all parts of the United States damage is produced each 

 year by leaf-eating insects, and the application of arsenicals, in the 

 form of poison sprays, has been demonstrated to be the most efficient 

 method of suppression or control. In the work of suppressing and 

 preventing the spread of the gipsy moth and the brown-tail moth, 

 spraying with arsenate of lead on an extensive scale has proved a 

 very important factor. The magnitude of the insect problem which 

 the ravages of the gipsy moth has developed in the New England 

 States made it necessary to devise extensive improvements in insecti- 

 cides and spraying machinery. 



HISTORY. 



When the work against the gipsy moth was first undertaken by 

 the Commonwealth of Massachusetts, the problem was one of ex- 

 termination rather than repression, and spraying with arsenical 



63392°— Bull. 480—17 



