318 RerreortT oF THE DEPARTMENT OF ENTOMOLOGY OF THB 
reliable results. The treating of a large number of trees was 
purposely avoided in order to give an opportunity of making the 
treatment thorough and accurate. 
OBJECTS OF THE EXPERIMENTS. 
The principal objects of these experiments were: To determine 
the effects of winter applications of kerosene oil (1) on healthy 
nursery trees and (2) on healthy bearing trees; (3) to determine 
the percentage of oil required to kill the scale during the winter; 
and (4) to determine the effects of summer applications upon 
healthy bearing trees. 
CONDITIONS. 
Unless otherwise stated only 150° fire test oil was used. In 
all cases the oil was applied in the form of a spray, the machine 
being frequently tested to ascertain whether the right propor- 
tions of oil and water were being maintained. Much care was 
also taken to make the applications even, each tree being wet to 
the same degree. 
PXPERIMENTS TO DETERMINE THE EFFECTS OF WINTER APPLICATIONS 
OF KEROSENE OIL ON HEALTHY NURSERY TREES. 
These experiments were divided into two series, the first receiv- 
ing one application and the second two applications.? 
Series I—Sprayed November 22; temperature 49°, high wind, 
cloudy. Weather during the week following alternately cloudy 
and bright, with average temperature of 27°. 
‘Unless otherwise stated, the trees in Series I and Il have received one 
and two applications of oil, respectively. 
