CONTROL OF ARGENTINE ANT IN ORANGE GROVES. 7 



THE ANT AND SOFT SCALES IN LOUISIANA. 



Mealybugs. The ant has not had any such decided effect in in- 

 creasing the severity of mealybug infestation in the orange groves 

 of Louisiana as in those of California. The mealybugs usually start 

 to increase rapidly in some groves of Louisiana in the spring and 

 early summer and threaten to infest certain of them severely. But 

 at ><>me time between June 15 and August 1 they are brought under 

 control by their natural enemies, regardless of the presence of the 

 ants. The common mealybug 1 is at present held in check in the 

 Louisiana orange groves partly by its natural enemies, partly by the 

 overcrowding of the trees with armored scales and white flies, and 

 partly by the poor condition of the trees. The insect does not cause 

 the slightest damage to the orange trees, nor does it blemish the 

 fruit, under present conditions in Louisiana. 



Fluted scale. The fluted scale never yet has been found in the 

 orange groves of Louisiana, except in small and isolated plantings 

 on the Metairie Ridge. It therefore may be dismissed with the 

 citrus mealybugs as of no present importance as a cause of injury 

 to orange trees in Louisana. 



Black scale. Although the black scale occurs in parts of Xew 

 Orleans where the ants are most numerous, the ant has not yet caused 

 any great increase of infestation there, and this scale has not come to 

 the front as a pest, even of the ornamentals on which it occurs. It 

 does not appear to be present in the orange groves proper of 

 Louisiana. 



Soft brown scale. In the Louisiana orange groves the soft brown 

 scale appears and disappears, being kept in check mainly by its in- 

 ternal parasites, against which the ants are relatively ineffective. 

 The scales form in larger groups on occasional branches of an orange 

 tree when attended by the ants than in cases where there are no ants. 

 Occasionally trees are found having one or more small branches 

 heavily infested, but even where the ants are most numerous the trees 

 are not infested to a seriously injurious extent. The largest groups 

 of soft brown scales occur on food plants other than orange trees in 

 Louisiana. 



From the foregoing it must be recognized that under present con- 

 ditions very little damage is done to the orange industry of Louisiana 

 by the Argentine ant through its relations with the unarmored, or 

 soft, scales. Only four of the six principal kinds of orange-infest- 

 ing soft scales occurring in this State have been found in the orange 

 groves proper. At least two of these four, namely, the Florida wax 

 scale 2 and the barnacle scale, 3 although attended by the ants, show 



1 Pseudococcus citrl (Risso). 



2 Ceroplastes floridenis Comst. 



8 Ceroplastes cirripedifurmis Comst. 



