8 BULLETIN 1079, U. S. DEPARTMENT OF AGRICULTURE. 



Coal-tar emulsion {prepared Tyy Insecticide Boa/rd) ; 1 part emulsion to 10 

 parts water.— Vme. logs dipped and sprayed were attacked after 15 days by 

 insects of type 4 and later by those of all types. Final results wer^ no better 

 than in the case of the controls. 



Crude petroleum. — Pine logs sprayed and dipped with crude petroleum were 

 attacked by insects of type 4 after 15 days and later by those of all types. 

 Final results were no better than with the controls. 



Anthracene oil emulsion {prepared Jjy Insecticide Board); 1 part emul- 

 sion to 10 parts water and 1 part emulsion to 100 parts water. — Dipped pine 

 logs were attacked by insects of type 4 after 15 days and later by those of all 

 types. The final results were no better than with the controls. 



Crude solvent naphtha. — Pine logs dipped with this material were slightly 

 attacked by insects of type 4 after 15 days and later by all types. Final 

 results were but little better than with the controls. 



Six ounces of nitrobenzene in one gallon of kerosene. — Pine logs sprayed 

 and dipped were attacked after 15 days by a few insects of type 4 and later 

 by more of the same type. The final results were somewhat better than with 

 the controls. 



Fish oil. — Pine logs sprayed and dipped were immediately attacked by 

 insects of type 4 and later by all types. Final results were no better than 

 with the controls. 



Two parts fish oil, one part pine oil, and three parts kerosene. — Pine logs 

 sprayed and dipped were attacked after 15 days by insects of type 4 and later 

 by all types. The final results were no better than with the controls. 



Kerosene. — Pine logs sprayed and dipped were attacked after 15 days by 

 insects of type 4 and later by all types ; results were no better than with the 

 controls. 



Sulphite concentrate {furnished by a paper-pulp imll) ; full strength and 

 diluted icdth equal parts of water. — Pine logs dipped were attacked after one 

 week by insects of type 4 and later by all types. Final results were no better 

 than with the controls. 



Spent sulphite; full strength and equal parts spent sulphite and a commercial 

 miscihle oil. — The results in pine logs dipped and sprayed were the same as 

 with sulphite concentrate. 



Tree gum {furnished hy Gipsy Moth Laboratory) ; 1 pound of tree gum 

 dissolved in 1 quaj-t of turpentine. — Pine logs treated with a brush were at- 

 tacked by a few insects of type 4 after two months. The results were much 

 better than on the controls, but the material held moisture in the log and pro- 

 duced much bluing of sap when insects penetrated the bark. The sticky film 

 act«d as a mechanical barrier. 



One pound of melted paraffin tcith one gallon of gasoline added. — Pine, ash, 

 and juniper logs were sprayed and dipped and placed in a cage for experiment 

 against insects of type 4. This treatment prevented all attack on the more 

 absorbent bark of ash and juniper. A few insects attacked the pine. 



One-half pound of naphthalene dissolved in one gallon of gasoline. — Dipped 

 pine logs were attacked after 15 days by insects of type 4 and later by all. Final 

 results were but little better than with the controls. The naphthalene soon 

 evaporates and no odor is left. 



One pound of ^netted paraffin with one-haif pound of naphthalene and one 

 gallon of gasoline added. — Pine, ash, and juniper sprayed and dipped and 

 placed in a cage against type 4 were attacked by insects of this type after 30 

 days. 



