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root containing about 5 percent rotenone is the suggested spray formula, 
and a dust should contain about 0.5 percent rotenone. 
Hot e none -b o ar irg sprays, when properly applied with adequate equip- 
ment, have proved highly effective in killing the pea aphid. The more 
recently developed rotencne-boaring lusts, as well as insecticides applied 
by moans of airplanes, while promising, have not yet been subjected to 
field tests sufficiently severe to bring out all their possicle limitations. 
Final judgment od these methods will have to be deferred until another 
season's work has hee-: completed. 
Field trials with derris, cube, timbo, and pyre thrum powders for 
control of cabbage worms indicated clearly that pyre thrum mixtures were 
more effective in circumstances where the cabbage looper (Au tographa 
brassicae Eiley) became the predominant species. Mixtures of comparable 
strength containing cv.be and pyrethrum powders wore not as effective as 
those containing pyrethrum powder clone. Spray mixtures were less 
effective than dust mixtures. 
Tests against the Mexican bean beetle were made with bordeaux mixture 
and rotenone-containing powders as a combination fungicide-insecticide spray 
for use on fall-grown lima beans. The results indicated tnat timbo powder 
in combination with bordeaux mixture was as effective as timbo powder alone 
as a spray. 
The United States Department of Agriculture, 3ureau of Entomology 
and Plant Quarantine (316), in 1936 published suggestions for the control of 
the pea aphid prepared by a committee of entomologists at the annual meeting 
of the American Association of Econoiiiic Entomologists at Indianapolis, 
Indiana, December 27, 1937. 
The following recommendations are based on observations and data 
accumulated from experimental work done east of tne Rooky Mountains. 
Satisfactory control of the pea aphid has been accomplished by 
several methods. These include, without suggestion of preference, (1) 
dusting, (2) use of nicotine vaporizer, and (3; spraying. Success in the 
use of exiy of these methods will depend entirely upon adequate and efficient 
equipment and properly timed, thorough application. (1) Dusting w ith 
De rr is or Cabe ; Field experiments with derris or cabe dust mixtures con- 
taining talc cr other suitable carriers, conditioned with a liquid spreading 
and wetting agont, have resulted in satisfactory control. Such dust should 
contain approximately 1 percent of rotenone. 
For information concerning spreading and wotting agents in sprays or 
dusts consult your Experiment Station Entomologist or the Bureau of Ento- 
mology and Plant Quarantine, U. S. Department of Agriculture. 
In applying these dusts the boom should be completely enclosed and a 
trailer 25 feet or more in length should be used. Dusts should be applied 
