30 PEELIMINAEY EEPOET ON ALFALFA WEEVIL. 
high in front, and adjustable in the rear. The top was of hght sheet 
iron bolted to the frame. 
Oil was pumped from a barrel in the conveyance to which this 
machine was attached and forced through a rubber hose into a supply 
pipe which fed the nozzles and burners underneath. The oil under 
pressure came forth from the burners as a mist of fire blowing into the 
stubble and against the ground. 
The sheet-iron cover served to hold the heat down while this oven 
passed slowly over the surface. In its unperfected state the machine 
did effective work and offered ideas of value, warranting the construc- 
tion of more efficient burners. 
In fields where there was a clean stand of alfalfa stubble this 
machine did very weU in burning vegetation and destroying aU insect 
fife above the surface of the ground. Where many weeds, especially 
dandefions, were present, the insects found protection under the green 
leaves. Where parts of fields were burned over, the unburned area 
showed no growth for several weeks on account of the continued 
weevil attack. The burned area turned green within a very much 
shorter time. 
REDUCTION IN QUALITY OF HAY CAUSED BY THE ALFALFA 
WEEVIL. 
Wliile studying the alfalfa weevil on various farms in the Salt Lake 
YaUey during the month of Aprfi, 1911, it was found that many farm- 
ers, through a shortage of forage, were feeding the weevfi-mjured 
hay of the first crop to their horses. This hay contained so many 
old cocoons and was so dusty from larval excrement and dead bodies 
of weevil larvae as to render it unfit as feed for horses. On several 
occasions horses were observed coughing from the effect of this dust. 
In fact, many farmers consider the first crop from severely infested 
fields ahnost valueless as horse feed. 
On June 12, 1911, at Alpine, Utah, when the new hay from the first 
crop was fed to work horses these began coughing almost immediately 
after starting to feed upon this injured hay. The hay contained 
large numbers of dead weevil larvae, some stiff .on the skeletonized 
leaves and some in the freshly spun cocoons. On September 13 hay 
from the first crop, in stack, was examined at Lay ton, Utah, and 
found to be very dusty, containing many dead weevil larvae and also 
pupae. 
NATURAL ENEMIES. 
The natural enemies of the alfalfa weevil consist of vertebrates and 
invertebrates. The former have been studied by assistants of the 
Bureau of Biological Survey, and a fist of species observed to attack 
the weevff is given herewith. 
