Washington, D. C. PROFESSIONAL PAPER August, 1922 
EXPERIMENTS WITH SPRAY SOLUTIONS FOR 
PREVENTING INSECT INJURY TO GREEN LOGS. 
By F..C. CratgHrEaD. 
Specialist in Forest Entomology, Forest Insect Investigations, Bureau of 
Entomology. 
CONTENTS. 
Page. Page. 
Uses for repellent sprays against for- Requisites of a practical spray—Con. 
est and shade-tree insects_________ ik It must first prevent all insect in- 
Requisites of a practical spray_______ 3 jury for from one to three 
It must be effective against sey- MONCH S 4b olCAS tae ee. 4 
eralehyDesObminSCCiS esas ee 3 | (Experiments with preventive sprays__ 4 
It must be effective on various Treatments and results______..__ {6 
SPECles! Of wWO00G === atts 2S + Remarks on poisons used_____-_ __ 10: 
It must not be leached off by rain Other experiments with insects of 
or other weather conditions_-—__ 4 LENA Genes po Ue ea Se 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. Itis 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 
