- 10 - 
Pure dermis powder and a 1 to 1 tnixture .of derris arid flour, applied 
with a shaker, about 1 o\ince per animal, killed all sucking -lice, Linognathus 
vituli L. , on calves. Mixtures of derris with flour, 1 to 5, 1 to 10, -and 1 
to 20, killed all "but a few of the lice. A mixture of equal parts of derris 
and.sodium fluoride killed all lice, L. vituli , and their eggs. 
Calves infested with Solenoptes capillatu s End. were dusted with mix- 
tures of derris with flour, 1 to 1, 1 to 5, 1 to 10, and 1 to 20. The 1-to-l 
mixture, 1-3/4 ounces per anim9,l, killed ''all lice, "but the weaker mixtures 
were not 100 percent effective. 
All sucking lice, Linognathus piliferu s Burm., and their eggs on a 
dog were killed "by 2 grams of a mixture of 1 part derris and 3 parts corn 
starch; also with a 1-to-l mixture of derris and flour. 
An ointment consisting of 1 part of derris to 2 parts of vaseline 
applied to the holes of war"bles in the "backs of cattle proved as effective as 
any other material used in this way. Five days after treatment all grubs 
were found to have been killed and the condition of the cysts was very 
satisfactory. A wash consisting of 1 pound of derris, 4 ounces of soap, 
and 1 gallon of water applied once with a brush to the backs of infested 
cattle killed practically all grubs. 
A series of tests with several breeds of dogs indicated that the 
'minimum dosage necessary to destroy all flease completely was 0.87 gram of 
a mixture of equal parts derris and corn starch per animal. When the 
quantity of derris was reduced to 0.2 gram 100 percent kill was not realized. 
Following these preliminary experiments, a mixture of derris and corn 
starch, in the proportion of 1 to 3, was applied to all the animals in the 
hospital at the time — 48 dogs and 9 cats. The material was put on along 
the bf'ck and neck of each animal with the thumb and finger. 'An average 
of slightly less than 2 grams per animal was applied. These animals were 
treated on December 4, and subsequent examinations up to December 10 showed 
no living fleas. Both dog and cat fleas — Ctenocephalides canis and C^. 
f elis — were present. 
In one test puppies rather heavily infested with the sticktight 
flea, Echidnophaga gallinacea , as well as the dog and cat fleas, were 
each treated with one gram of undiluted derris. In a few hours dead dog 
and cat fleas began dropping off the hosts and thefollowing day all 
specimens were dead,, though many sticktights remained attached. 
The authors concluded: 
"Derris powder is satisfactory as a" destroyer of Mallophaga 
on chickens and cattle, but apparently not quite as effective on 
the latter as sodiiim fluoride. 
"It is very effective against Anoplura on cattle and dogs, 
one treatment accomplishing the destruction of all stages. 
