24 INSECTS INJURIOUS IN 1902. 
turned to fish oil. Fish oil costs in Minneapolis 45 cents per gallon 
in barrel lots; 48 cents by the half barrel and 60 cents for a single 
gallon. This vile smelling oil was used alone, being sprayed on 
the steer and was not very effective compared with the solution 
we prepared by adding one part kerosene to three parts fish oil. 
One man can spray an animal with this in two or three minutes 
provided the animal is held to prevent its moving about. An ex- 
amination of a steer two days after treatment with this mixture 
(1 part kerosene, 3 parts fish oil), showed it to be absolutely free 
from flies, while other cattle not treated all about it were suffer- 
ing. 
If I were keeping two, three or four family cows I should not 
hesitate to use the kerosene and lard mixture mentioned above. 

Fig. 22.—Blow fly (S. carnaria). Lugger. 
A large herd could be better treated, of course, with the spray 
pump and the more disagreeable fish oil and kerosene mixture. 
The lard used in these experiments was rancid, perfectly good for 
the purpose but not saleable for culinary use. Not only Horn 
Flies but the Stable Fly, Stomoxys calcitrans, Linn., and the com- 
mon Green Bottle, Lucilia cornicina, Fab., and Flesh flies, Sar- 
cophaga carnaria, Linn., were effectually kept at a distance by the 
treatment referred to above as the best. 
