-54- 
were applied when the outside temperature was as low as 20° F. , tut, 
although the cattle were exposed to cold, inclement <-eather, no injury 
n es detectable. 
The United States Department of Agriculture, 'Bureau of Entomology 
and Plant Quarantine -( 297 ) in 1941 celled attention to the presence of 
both the common and the northern cattle grubs in northern Colorado and 
across Wyoming, =nd to a demonstration of their control with cube -"ash 
at a ranch ne?r Parlcman, W yo . It was planned to treat about 15,000 head 
of range cattle for cattle-grub control. 
H yooderma sp . " - ■ ; 
In December 1916, Lemmens and Fryer applied for certain British ( 17? ) 
end -German (176, 177 ) patents covering the use as insecticides of powder 
and extract of Tephrosia , particularly mentioning T, vogelii . The 
patentees stated that the purpose of the invention tss to provide 
improved means for the destruction of insects, vermin, and similar para- 
sites of various animals and plants, such means being suitable for ready 
use as an insecticide powder or wash for spraying upon plants, trees, and 
other vegetable growth, and upon soil, and as a sheep. dip, a cattle 
dressing, or a wash for animals, whereby the parasitic pest could be 
destroyed without injury to the plant or eniraal life. In 1917 Lemmens 
and Fryer ( 174 , 175 ) applied for and were- granted United States patents 
covering the same invention. 
Bishopp, Laake, end Fells ( 30) in 1922 stated that a single appli- 
cation of derris in soapy water applied with a brush to the backs of 
infested animals killed almost 100 percent of. Hypoderm e larvae. 
Wells, Bishopp, and Laake (312) in 1922 reported that an ointment 
consisting of 1 part o^ derris to 2 parts of vaseline, applied to 
warble holes in the backs of cattle, was as effective as anv other 
material used in this ^ay. Five days after-treatment all grubs were 
found to have been killed r.n* the condition of the cvsts -"?s very satis- 
factory. A -ash consisting of 1 pound of derris, 4 ounces of soap, and 
1 gallon of ^ater, applied once 'ith'8 brush to the backs of infested 
cattle, killed practically all. grubs. 
Hadwen( l30 ) in 1933 referred toj the. killing of Hypoderw e larvae 
by the application of derris to the warble boles . 
Bishopp, Laake, and Wells (31) in 1929 reported that for the con- 
trol of cattle 1 frubs in the backs of cattle an ointment consisting of 
powdered derris root, 1 part, and petroleum, 10 parts, pave excellent 
results. Fine derris ponder ^s very effective. As a '-ash, derris 
powder 1 pound, *at«r 1 gallon^ and -soap 2 ounces briskly rubbed in 
with a brush gave a lOO^-pcrcent kill in many cases. A pound of derris 
powder is sufficient for a general application to the backs of 20 to 
25 heed of cattle. 
