CONTROL OF ARGENTINE ANT IN CALIFORNIA. 
15 
of ants but their effectiveness was lost upon exposure to the 
weather. Once wet these insecticides are valueless. These powders, 
especially the pyre thrum, singly or in combination with the sodium 
fluorid, are decidedly repellent to ants and quickly cause death 
once they come well in contact with their bodies. The fact 
that their strength is soon lost on exposure to air restricts their 
usefulness. 
The following experiments demonstrate the comparative efficiency 
of these substances used singly or in combination. Breeding cages 
containing a large amount of mealybug-infested lemons and potato 
sprouts were heavily attended by ants which entered in steady 
streams along the legs. The legs were set in tops of fruit jars contain- 
ing a small amount of sodium fluorid powder. Ants continued to 
cross in limited num- 
bers for about one 
hour before the trails 
were completely bro- 
ken up. No dead 
ants were found. 
Pyrethrum powder 
was sprinkled about 
the legs of one cage, 
stopping the trails 
almost immediately. 
Dead ants began to 
pile up in the powder 
and on the floor about 
the powder. 
A mixture contain- 
ing pyrethrum 1 part, 
sodium fluorid 7 parts, and plaster of Paris 2 parts, was dusted 
about the legs of a breeding cage attended by ants with effects 
about as satisfactory as with pyrethrum alone. 
Corrosive Sublimate Ant Bands 
Corrosive sublimate has long been known to possess merit as a 
repellent to ants and this fact has been utilized in protecting materials 
from these pests. A common method is to soak narrow strips of 
cloth in a saturated solution of this chemical and use these as barriers. 
The saturated solution is best prepared by heating about 1^ ounces 
of corrosive sublimate in an ounce of water until the maximum 
amount is dissolved. The solution is then allowed to cool, is filtered, 
and the cotton band or tape is soaked in it for several hours. The 
tape is then removed, allowed to dry, and is ready for use. This 
amount of solution is sufficient for from 10 to 12 yards of f-inch tape. 
Fig. 6. — Repellent ant powders: a, Pyrethrum: b, pyrethrum 30 per 
cent, sodium fluorid 70 per cent. Shaker and blower for applying. 
