THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 71 
to which must be added an additional $0.08 for transportation and 
setting up, making a net cost of $0.31 each. The covers were made 
and delivered for $0.75 each. On this basis the first cost of traps 
and covers per acre would be about as follows : 
25 traps, at $0.31 each $7. 75 
3 covers, at $0.75 each 2. 25 
Net cost of traps and covers per acre 10. 00 
A crew of three have in practice fumigated 400 traps in 1^ eight- 
hour days, their services, at the rate of $1.25 per day each, costing 
$5.62. The carbon disulphid at that time cost $10.75 per hundred 
pounds. On this basis the cost of fumigating per acre of 100 trees 
per time would be about as follows : 
Cost of labor fumigating 25 traps, at $0.014 $0. 35 
Cost of fumigant, 25 traps, at $0.013 . 325 
Net cost of fumigation per acre . 675 
SUMMARY AND CONCLUSIONS. 
Most of the orange groves of southern Louisiana, with the excep- 
tion of well- tended groves and seedling orchards, have been de- 
clining in the last seven or eight years. As a rule, maximum pro- 
ductiveness is reached at from 7 to 10 years of age, after which it 
diminishes, the actual crop loss up to 1914 being approximately 37 
per cent of the known possible production. The principal cause of 
this decline of trees and loss of crop, which has been largely blamed 
upon the Argentine ant, is cultural neglect. 
The part played by the ant in causing this condition has been 
exaggerated. The only direct injury done by the ant is to destroy a 
negligible number of orange blossoms. The ants do not attend the 
armored scales of citrus or secure honey dew from them, nor do 
they disseminate the living scales. They do, however, disturb the 
predatory enemies of these scales, preventing the destruction of as 
large a proportion of them as would otherwise occur. Nevertheless, 
the natural enemies of the armored scales do not prevent heavy in- 
festation even in orchards free from ants. The ant can not prevent 
the control of the armored scales in Louisiana by spraying nor will 
it increase the cost of spraying. Destruction of the ants will not 
control these scales, and they must be controlled if orange growing in 
that State is to be made profitable. 
Under present conditions the Argentine ant does not cause excep- 
tionally severe infestations in the orange groves of Louisiana, even 
of those soft scales to which it is most favorable. The mealybugs 
have not been of importance as an orange pest in ant-invaded or- 
chards during the years 1913 to 1915, partly due to the effective- 
