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"The results rf its use against fleas on dogs and cats are 
probably most striking, very small amounts being sufficient to 
destroy all fleas present. 
"It appears to be effective for lice and fl^^as when reduced 
v/ith from one to ten' parts of a carrier to one part of derris." 
Brittain (l2) in 1922 reported that when derris (3 pounds to 100 
emperip.l gallons of water) was applied to cabbage plants (Copenhagen 
Market variety), 3S percent of the plants were destroyed by maggots. In 
another test 2 pounds of derris to 100 imperial gallons of water permitted 
about 29 percent of the plants (Early Jersey Wakefield variety) to be 
destroyed. Tests in which 3 pounds of derris to 100 imperial gallons were 
used permitted from 45 to 80 percent of the plants (Early Jersey Wakefield 
variety) to be destroyed by maggots. On radishes, derris (3 pounds to 
100 imperial gallons) allowed 71 percent of the plants to be infested v;ith 
cabbage maggots. Corrosive sublimate v/as the only treatment that gave 
satisfactory control. Only one material, derris, proved very ineffective. 
As it was from the same lot of material used the previous year with fair 
results, Brittain assumed that it had deteriorated in storage. About two- 
fifths pint of liquid and five-ninths ounce of dust was applied per plant. 
De Bussy (14) in 1922 reported the results of tests of various 
materials upon the larvae of Frodenia litura P. This lepidopterous insect 
is of great importance in relation to tobacco culture in Deli. The finely 
ground root of Derris elliptica (toeba) was used as a decoction in water 
up to 10 grams per 100 cc. yet in no case killed more than 2 out of 5 
half-grown caterpillars. ^ 
Gilmer (44) in the 1922 report of the Minnesota State Entomologist 
reported tests made with derris powder furnished by the American Tobacco 
By-Products and Chemical Corporation, of Louisville, Ky.; also with a 
derris extract said to contain 16 percent of active derris and 84 percent 
of inert substances, apparently pyridine. Both these products were manu- 
factured by a British company. The tests included the following mixtures: 
(l) derris powder 10 percent, tobacco dust 90 percent; (2) derris powder 
'7-1/2 Toercent, tobacco dust 92-l/2 percent; (3) derris powder 100 percent, 
tobacco dust percent; (4) derris powder 20 percent, tobacco dust 80 
percent; (5) derris powder 7-l/2 percent, tobacco dust 67-l/2 percent, 
powdered sulphur 25 percent. 
The experiments were of two general types, those performed with 
the derris powder as furnished, and those with the liquid derris extract. 
The tests were made on cats, dogs, white rats, and chickens; fleas, lice, 
chicken lice, and cockroaches. The fleas included the rat flea, Cerato - 
phyllus fasciatus Bos3., and the dog and cat fleas, Ctenocephalides canis 
Curt, and C. felis Bouche'. The chicken lice included both the body louse, 
Menopon biseriatum Piaget, and the head louse, Lipeurus heterographus 
Nitzsch. The rat louse, Polyp lax spinulosus Burm., was the common louse 
of these animals. The cockroaches included the American roach, Periplaneta 
aiTiericana L., and the croton bug, Blatella germanica L. 
