260 Report OF THE DEPARTMENT OF ENTOMOLOGY OF THE 
Weather during tests in Table IX.—Spring treatment. Trees 
sprayed April 19. Temperature 34°, cloudy with slight rain. 
Weather during the week following cloudy with frequent show- 
ers. Average temperature 48°. | 
TABLE IX.—SprRING SPRAYING IN ORCHARD III. 



Trees. Strength 
ee ee ae ee of 
Nutwber Re 
Kind. treated. Degree of infestation, cum. Results. 
Per ct. 
APPLE: 
Baldwin ..... 8 2 Hxtensively and 6 25 Seales not affected. 
moderately infested. Trees uninjured. 
Baldwin ..... 8 1 Extensively and 3 40 Scales dead, except on 
moderately infested. some of the small 
branches where 
many live ones were 
found. Trees wun- 
injured. 
SUMMARY FOR ORCHARD III. 
The results in this orchard show only partial success for the 
treatment. As with the other experiments the 25 per ct. 
emulsion had no noticeable effect on the insect. The lack of 
thorough work with the 40 per ct. emulsion appeared to be 
due to the difficulty of reaching every limb and twig on large 
trees. This seems evident because nearly all of the scales were 
dead, the live ones being found only on a few small branches 
that might easily have escaped thorough treatment. The 
serious injury to the eight trees sprayed during the winter with 
the 40 per ct. mixture was unexpected. As apples are not 
considered especially sensitive to treatment with crude petro- 
leum and similar insecticides and as the other apple trees in- 
cluded in the experiments were not seriously injured by similar 
treatment it seems probable that some other factor besides the 
petroleum must have had an important influence. ‘The apple 
trees that were uninjured by the winter treatment of 40 per 
ct. emulsion were not trimmed just before being sprayed as 
was the case with the injured trees, and as the pruning was 
unusually severe it may have weakened the trees sufficiently to 
cause them to succumb to the treatment. 
