428 ALFALFA FARMING IN AMERICA. 
heavier than air, sinks downward and comes to fill every cham- 
ber and gallery, destroying all the occupants. 
It must be remembered that carbon bisulphide is as explosive 
as gasoline and must be used with equal care. 
Conclusions.—The conclusions of Prof. Headlee as 
to the proper way to combat these insect enemies of 
alfalfa are as follows: 
When we call to mind that the grasshopper passes the winter 
in the soil in the egg stage, the web worm, army worm and cut- , 
worms remain in the soil over winter as larvae, the fall army- 
worm as a pupa, that the blister-beetles are dependent upon a 
supply of grasshopper eggs for food during one necessary stage, it 
is plain that thoroughly stirring the soil with a disk-harrow 
(preferably the spike-tooth kind) just after the frost is out of the 
ground and before the plants begin to grow, or, better still, in the 
late fall just before the ground freezes, if such a proceeding 
would not injure the plants, will go far toward controlling the in- 
sects enumerated. During the summer, when these insects are 
in the field or when the alfalfa is attacked by clover hay worms, 
leaf-hoppers, mound-building prairie ants or packet gophers, the 
grower must resort to measures especially fitted to destroy the 
enemy in question. ‘ 
To this I would add that in the eastern states 
insect enemies are much less in evidence in alfalfa 
fields, owing probably to the cold, wet winters, and 
the pocket gopher has not yet been introduced, 
though he is probably on his way. Woodchucks or 
groundhogs are a pest in eastern meadows; they are 
readily destroyed by use of bisulphide of carbon. 
The way to use it is to saturate a rag with a table- 
spoonful or more, throw it down the burrow as far 
as you can and immediately stop the hole tight. A 
sod may be laid over it first, then earth heaped on it. 
All holes should be treated as they may communicate 
with each other. 
