-97- 
In September 1943 the rotenone was reduced in dusts for cattle 
grub treatments. The rotenone dusts mixed with tripoli earth or 
with pyrophyllite are more efficient than those made with talc or 
sulfur, because the former penetrate the hair better and also be- 
cause twice as many animals or more can be treated with the same 
amount of derris. Two dust formulas were recommended: (l) Ground 
cube or derris (5 percent of rotenone) 1 part by weight, and tripoli 
earth (No, 200 sieve fineness) 3 parts by weight; and (2) cube or 
derris, the same as in (l), and pyrophyllite (No. 325 sieve fine- 
ness) 4 parts by weight.— U. S. Bureau of Entomology and Plant Quaran- 
tine (629) ♦ 
Nearly 800 cattle were treated in Colorado, New Mexico, and 
Texas in 1943 for cattle grubs. Indications are that dipping cattle 
in a suspension prepared by adding cube powder (5 percent of rote- 
none) at the rate of 10 pounds per 100 gallons of water is as ef- 
fective, in many cases, as the use of washes and dusts containing 
cube or other rotenone-containing substances. In some instances dip- 
ping is more effective than the latter methods.— U. S. Bureau of Ani- 
mal Industry (614 , p. 86). 
Rotenone to treat cattle for cattle grubs costs less than 10 
cents per animal per season. It would be possible to kill every cattle 
grub in Idaho during one season if all cattle producers and feed- 
ers would cooperate in the control program.-- Shull (539) . 
In Kansas a State campaign was conducted against cattle grubs 
in 1944. In 1943, 116,000 cattle were treated, and in 1944 it was 
planned to treat 1,000,000. In a demonstration for county agents 
and farmers, four methods were shown: (l) The old method of squeez- 
ing the grubs from the backs of animals, (2) the wash method of ap- 
plying the cube-wettable sulfur, (3) the dust method of applying the 
cube-tripoli earth, and (4) the spray method of applying the rotenone 
preparation with a sprayer»~Kelly (340) . 
The effectiveness of the following dusts was found to be in the 
order in which they are given below: 
Parts by weight 
Ground cube or derris (5 percent of rotenone)— 1 
Double-ground or earn tripoli earth ————«-— 2 
or 
Ground cube or derris (5 percent of rotenone)— 1 
Volcanic ash (micronized)— — — — — — — — 2 
or 
