ANIMAL PESTS AND DISEASES. 42% 
stems. The dozer is filled with water and coated 
with a film of kerosene. It is used in the warm part 
of the day because then the hoppers are decidedly 
most active. 
When it is drawn forward through the infested 
field, the hoppers spring to get out of its way and 
most of them may land in the water and be de- 
stroyed by contact with the kerosene. If enough 
turkeys and guineas are kept hoppers will be much 
reduced in numbers. 
Ants—Webworms, army worms, fall army 
worms, cutworms and blister beetles all occasionally 
injure alfalfa more or less. Mound-building ants are 
troublesome in western fields. The ants are readily 
destroyed by use of bisulphide of carbon. Taking 
note that the ants are canny and carefully guard 
their homes, Prof. Headlee thus comments: 
On the approach of a storm a large force is employed and the 
gateways are closed in haste, but when it has passed they are re: 
opened and the ants return to their work. 
The ant colonies are too few to decrease the yield seriously, 
although occasionally they will destroy the alfalfa on from one 
to two per cent of the total area of a badly infested field. Their 
claim to rank as alfalfa pests lies principally in the increased 
difficulty of harvesting the crop when they are present. 
Extended experiments have shown that the ants can most 
easily and efficiently be controlled by fumigating the nest with 
carbon bisulphide as follows: Set fumigation only when gateways 
are open; invert a galvanized iron vessel, such a common wash- 
tub, over one or more of the openings, covering as much of the 
mound as possible; firmly pack soil over such holes as the tub 
will not reach; introduce under the tub and near the holes a 
shallow dish containing from one to three ounces (depending on 
the size of the nest) of carbon bisulphide; set the tub down and 
quickly pack soil about the rim, making it as nearly air-tight as 
possible; allow to stand for five hours. The forming vapor, being 
