56 BULLETIN 647, IT. S. DEPARTMENT OF AGRICULTURE. 
CULTURAL CONDITIONS IN ANT-INVADED VS. ANT-FREE 
ORANGE GROVES IN LOUISIANA.* 
As already stated, the Argentine ant infests only slightly more 
than 26 per cent of the orange groves of Louisiana as yet. It was 
found that 40.7 per cent of the groves that had never had the ants 
in them were in " poor " condition, while about the same proportion 
(43.9 per cent) of those, that were infested with ants were in good 
condition. In other words, about 15.4 per cent more of the ant- 
invaded groves were in " poor '■ condition than of the noninvaded 
groves, but this is probably in large part clue to the greater neglect 
of the ant-infested trees because of that infestation, many of the 
owners becoming discouraged as soon as they found the ants present. 
A considerable number of groyes had been abandoned completely 
because the ants had gotten into them. A slightly greater reduction 
in crop had occurred in the groves infested by ants, this reduction 
being, however, only about 0.22 box per tree greater than in those 
free from ants. Both the maximum and the last (1914) crops were 
far below what they should be in both ant-invaded and ant-free 
orange groves for trees of their age, being in each case less than 
1 packed box per tree. In Cameron Parish the large sweet seedling 
orange trees, in which the Argentine ant does not occur, helped to 
raise the production average for the groves free from ants, as these 
trees produce from 5 to 15 boxes each. 
Thus it is seen that there is practically no difference between those 
groves in Louisiana where the ants are present and those where they 
are not, either in the condition of the trees or in the amount of fruit 
produced. It is undoubtedly true, however, that where the scale, 
white-fly, and rust-mite infestations are heavy and no attempt is 
made to control them the crop will be reduced considerably. The 
effect of these insects also will be unusually pronounced on trees that 
are weakened by too close planting, poor drainage, and cultural 
neglect. The ants appear to have no effect on the rust mite. 
That groves completely overrun Avith the ants and in a badly run- 
down condition from neglect can be revived and brought back to 
their normal bearing condition without treating the ants or keeping 
them from the trees has been demonstrated. The principal features 
of this work will be related here briefly. 
1 The data on conditions affecting the culture of orange trees in Louisiana were obtained 
partly by means of questions submitted to the orange growers, partly by personal inspec- 
tion of the groves, and are complete on about 96 per cent of the groves of the State. * 
Those groves with a large percentage of trees fairly large for their age, symmetrical, 
with moderately dense foliage, of good color, and bearing an average-sized crop according 
to local standards, were classed as " good." Those showing a large percentage of under- 
sized trees, with thin foliage, many dead and dying branches, poor color, lack of growth, 
and poor crop were classed as " poor." 
