THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 57 
DEMONSTRATION IN IMPROVEMENT OF ANT-INVADED GROVES 
IN LOUISIANA. 
If preventing the Argentine ant from getting into the orange trees 
would effect the practical commercial control of the chief armored 
roales and the white fly in Louisiana, as it does that of the citrus 
mealybugs in Los Angeles County, CaL, the problem of controlling 
these insects would be simply one of getting rid of the ants. The 
natural enemies of the principal pests of Louisiana, however, are 
unable, even in the absence of ants, to prevent severe infestation. 
On the other hand, if thorough measures of control were practiced 
against these insects, there should be no reason to worry about the 
ants. If the citrus mealybugs in California orange groves were as 
thoroughly controlled by the regular fumigations as are the armored 
and black scales, the ants could do only a negligible amount of harm 
through these insects. 
DESCRIPTION OF DEMONSTRATION ORCHARD. 
The orchard reclamation work about to be described was conducted 
on a grove at Ollie, La., practically abandoned, except for the har- 
vesting of the crop. The grove consisted of about 1,055 sweet, naval, 
mandarin, tangerine, and Jaffa trees, a block of 603 of which were 
treated, the remaining 452 being left as checks. All the trees were 
Aery thinly foliaged, with small tops, and many of them with mul- 
tiple trunks. Many of the leaves Avere yellow and a moderate num- 
ber of branches were dead. The trees were poorly shaped, and 
branches were much tangled as a result of bad pruning. Many 
of the trees were suffering badly with gummosis, 1 some being almost 
completely girdled about the base of the trunk and larger roots by 
this disease. (See PI. III.) 
The ant infestation was as heavy as has ever been seen in any orchard. 
All the trees were very badly infested with chaff, purple, and long 
scales, the first named being exceptionally numerous. Almost all the 
fruit had been very badly discolored by the rust mite every year, and, 
in some years, infestations of the citrus white fly were also severe. 
The largest crop ever produced by the full orchard of 1,055 trees 
was 1,400 boxes, occurring in the year 1911. The crop of the 1914 
season had been only 400 boxes; or, in other words, the orchard had 
suffered a crop reduction of 71.4 per cent in three years. 
TREATMENT OF THE ORCHARD. 
The demonstration work of improving this grove was started in 
February, 1915, and continued until interrupted by the hurricane of 
1 Also called " sore shin " disease. 
