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A writer signing as G. E. 0. (222) in 1934 gave the following 
formula for warble control: Derris 1 pound, soft soap 1 pound, 
in v?ter 1 imperial gallon. 
Vogel (303) in 1934 reported that three derris extracts diluted 
1:50 caused 90.8, 56.8, and 58.1 percent^ respectively, of the 
war Dies in. the backs of ca tie to heal,. An extract diluted to 
contain 0.24 percent of rotenone. caused 95.6 percent to heal and gave 
the "best control of any material tested. Derrilavol, Derri-Tox, Derro- 
emulsion;, Deumos, Dasselfliegenbekampfungsmittel, Panderran I and II, 
an'd Cooper'^. Garble. Fly powder were other derris- products tested. 
Zunker { :35l ) in 1934 reported tests of proprietary; derris pro- 
■ ducts againat Hypoderna larvae in the backs of cattle.. Abdassol (also 
■called D8) killed 63 to 95 percent; D7 , 67 percent; B9, 90 uercent; and 
Polvo,plus soap;, 74 percent. • . 
An anonymous (5) Dutch writer in 1935, recorded results against 
.cattle grubs .'with two lots of .derris, one containing 2 percent of 
rot-enone and 8 percent of ether extract,, used at the- rate of 1 kg. to 
9 liters of water, plus 250 gm. of green soao in 1 liter of water; 
the r other containing. 8, percent. of rotenone and 21 percent of ether 
extract used at the rate. of 1 leg. to 40 liters of water. Soap is 
not; necessary; neither is soaking .the ponder, in water. Satisfactory 
control of the cattle grub was also obtained with rotenone, 10 gm. 
in 250 cc. of acetone added to 4 liters of water. 
DeBussy et al..-(49) in '1935 "rote th'-.t derris was an established 
remedy for the control of werble flies. 
• f Spoon ( 258 , 259 ) in 3935 "Tote that for use against Hypoderma , 
derris powder 'containing 2 percent of rotenone and 8 percent of 
ether extract was agitated in 10 parts of water for 24 hours, and 
to the mixture was. added 0.25 -pert of green soap in 1 part of water. 
The suspension was rubbed into the back of the animal .with a small 
brush, an average 250 cc. being used for each animal, ^hen derris 
powder containing 8 percent of rotenone and 21 percent of ether 
extract was used, 1 part of derris w?s suspended in 40 parts of water. 
The addition of soap was found to be unnecessary. Satisfactory con- 
trol was also" obtained 'by suspending 1 part of derris (8 percent 
rotenone, 21 percent ether extract) in 10 parts of water, and apply- 
ing the suspension immediately. It was not known whether lower con- 
centrations would be effective without a longer period of extraction. 
Later that year Suoon reported on theuse of derris powder iii Holland. 
In the Wieringermeer- district, 65 kg. of derris powder containing 8 
percent of rotenone was used for the treatment of 4,000 yearlings, 
2,000 of which received a second application. On the island of 
Ameland, 20 kg. of derris (same sample) was used "for the treatment 
of 1,635 cattle. The cost of derris ponder for a single treatment 
amounted to about 2 cents in American currency. The method, of ampli- 
cation was as follows: 400 gm. of derris oowder was suspended in 
