-63- 
hours, after., which 250 gm. of soft soep dissolved in 1 liter of w eter 
wasedded. .The extract ,a es prepared just prior to use. As a rule 
one application v 'f^ sufficient, but a. second made a" few days later 
ensured the death of all the larvae. The mixture was well brushed 
onto the backs of the animals, 5 to 14 fluid ounces "being reouired 
for each. An ointment of vaseline containing 2 percent of rotenone 
elso gave excellent results, the hair around the garble having been 
cut before- its application. Rotenone dissolved in the oil killed the 
larvae, but the resultant irritation makes it unsatisfactory in 
practice. Mixtures of rotenone with turpentine also caused irritation 
and were not so effective. 
G'Otze ( 123 ) in 1933 reported on the value of a number of pro- 
prietary derris products for the control of ox warbles. Products 
tested ^ere: Derrothan-emulsion, Ludwig Meyer's oily preparations 
Nos*. 2068 and 2069, end three rotenone or derris solutions sold by 
the Chemische Fabrik Marienfelde and designated Indis-sine-rotenone- 
•Lb'sung, India-rotenone-L'dsung, and India-gesemtextrakt-Losung. T<"0 
applications of a product containing 8 percent of rotenone diluted 
1:50 killed 96.4 percent of the marbles. 
Gusenol, a pronrietarv derris ointment, ,T, as recommended for the 
control of ox marbles by the Illinois Agricultural Experiment Station 
( 145 ) in,. 19 33. 
Peters ( 231 ) in 1933 reported on warble control in Germany. One 
kg. of fine derris ponder "'as soaked in 9 liters of cold • r, ater for 24 
hours. To this was added 2.5 kg. of soap in 1 liter of ^eter. Two 
applications of this mixture killed ell marbles in the becks of cattle. 
Remien ( 237 ) in 1933 reported on the value of some proprietary 
derris products, including Derrothan-emulsion,' Ind.ie-rotenone-Losung, 
India-cesamtextrakt-Lbsune, and Indie-sine-rotenone-Losune:, for 
controlling Hypoderma larvae in the backs of cattle. All warbles on 
animals w? shed twice with an aqueous solution of 0.68 percent of 
rotenone end 2.5 percent of soap were killed. 
Spoon ( 257 ) in 193? reported that rotenone 'was of great value 
in the control of cattle grubs. 
The United- States .Department of Agriculture, Bureau of Animal 
Industry (280) in 1933 recommended' the use of derris against cattle 
grubs, stating the t animals infested can be effectively and safely 
treated by the owner "'ith small medicated rods inserted, in the warble 
holes. This method appears to be the most effective, rapid, end safe 
so far devised for use by the cattle o^ner. Of a large number of 
formulas tested, the one that gave the best results ™es: Gum erebic 
6 drams, glue 2 drams, tannic acid powder 2 drams, derris powder 1 
ounce, and enough water to meke e stiff paste. This paste is then 
rolled into the form of rods, ^en properly used, the rods are 100- 
perfcent effective in killing grubs. The ingredients arc- harmless to 
cattle, and the preparation is easily standardized. There appears to 
-be little danger of spreading infection from one lesion or enimel to 
another, a thing which often occurs v, hen infected instruments ere u-ed. 
