UNITED STATES DEPARTMENT OF AGRICULTURE 



Washington, D. C. 



PROFESSIONAL PAPER 



August, 1922 



EXPERIMENTS WITH SPRAY SOLUTIONS FOR 

 PREVENTING INSECT INJURY TO GREEN LOGS, 



By F. C. Craighead/ 



Specialist in Forest Entomology, Forest Insect Investigations, Bureau of 



Entomology. 



CONTENTS. 



Page. 



Pag«. 



Uses for repellent sprays against for- 





Requisites of a practical spray — Con. 



est and shade-tree insects 



1 



It must first prevent all insect in- 



Requisites of a practical spray 



3 



jury for from one to three 



It must be effective against sev- 





months at least 4 



eral types of insects 



3 



(Experiments with preventive sprays__ 4 



It must be effective on various 





Treatments and results 7 



species of wood 



4 



Remarks on poisons used 10 



It must not be leached off by rain 





Other experiments with insects of 



or other weather conditions 



4 



types 10 



It must not be expensive 



4 



Poisoning of ambrosia beetles 11 



USES FOR REPELLENT SPRAYS AGAINST FOREST AND SHADE- 



TREE INSECTS. 



During the past few years there has been an increasing demand for 

 a practical spray that will prevent insect attack to crude forest prod- 

 ucts such as green saw logs and timbers used in rustic construction. 

 Numerous requests for such a spray are received by the Bureau of 

 Entomology. These inquiries often number more than a hundred 

 through the summer months. 



Although many lumbering firms request a spray for this purpose, 

 it is doubtful whether it would be really practical under ordinary 

 conditions. During the flight period of those insects which cause the 

 injury it would be necessary to apply the spray immediately after 

 felling the trees. It is more practical to prevent insect injury in lum- 

 bering operations by some alteration in the methods of management, 

 as by more prompt handling between felling and sawing or by sub- 

 merging the logs in water, than by spraying. 



1 Resigned December 31, 1920. 

 102230 — 22 1 



