264 



Bulletin 38. 



young trees, and is now very widely distributed in the apple orch- 

 ards. It has two forms, one which lives on the branches of the 

 trees, the other upon the roots. The former, although naturally 

 the most conspicuous, is much the least harmful. 



Many experiments have been made for the destruction of the 

 woolly louse of the apple, and the results are well summarized by 

 Mr. C. L. Marlatt in Circular 20, Division of Entomology, U.S.D. A. 



Fig. 4. Woolly louse of the apple. — a, Agamic female; 6, young louse; c, 

 pupa; d. winged female, with antenna enlarged above. All greatly 

 enlarged, and with the waxy secretion removed. (Marlatt, Circular 

 20, 2nd Series, Div. Entomology, U. S. Dept. Agriculture). 



The form which occurs on the branches can be killed by a 

 spray of kerosene emulsion or soap wash, best applied warm. It 

 can also be destroyed by applying kerosene to the colonies by 

 means of a paint brush. This should be done, if possible, early in 

 the year. 



The root form is not so easily got rid of, but the following 

 remedies have succeeded : 



i. Hot water may be applied about the roots of the trees, 

 the surface soil having been first removed. 



2. Finely ground tobacco dust may be applied about the 

 base of the trees, first removing the soil to a depth of 4 to 6 inches. 



