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THE EUROPEAN ELM SCALE IN THE WEST. 15 
The results of these washing experiments have been previously re-— 
ported in considerable detail (7). 
SPRAYING EXPERIMENTS. 
Sprays consisting of distillate emulsion, kerosene emulsion, or 
erude-oil emulsion at strengths varying eae. 3 to 5 parts water to 
1 part emulsion proved entirely unsatisfactory for the control of the 
European elm scale, only 20 to 60 per cent of them being killed. A 
solution of 1 pound of fish-oi] soap and 7 gallons of w ater was used 
upon some molting females but was completely unsuccessful. <Al- 
though other experimenters have reported fair results from the use 
of lime- sulphur, the writer’s results with it were unsatisfactory, 
practically none of the insects being killed. This material can not 
be used in shade-tree work to any oreat extent because the sulphur 
in it combines with the paint on buildings and turns it black. 
Fic. 5.—Washing large elm trees with water from fire engine to remove the European 
elm scale. 
The best results were obtained from miscible-oil sprays. Those 
containing 28° Baumé oil were found to be very satisfactory, whereas 
those containing 33° gave very poor results. The former were 
efficient at the proportions of 1 part oil to 9 and 12 parts water, and 
certain brands of them at the greater dilution of 1 to 15 parts water. 
Miscible oil 28°, 1 part to 12 parts water, is the material to be re- 
commended. 
RECOMMENDATIONS FOR CONTROL. 
Kither of two materials is recommended for the control of this 
insect, a solid stream of water or a miscible oil spray. The garden 
hose and nozzle may be used to good advantage where a few small 
