632 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



The poison used to protect trees from these ants in the Cali- 

 fornia orange groves has been described in the discussion of the 

 mealy-bugs. An interesting account of methods of trapping and 

 of poisoning to rid orange groves in Louisiana of the ants will be 

 found in the publication by Mr. Horton to which reference has 

 been made. 



There seems to be little doubt that, serious as this insect is, it 

 can be controlled in orange groves and in dwellings, but that it is 

 almost necessarily a problem for community action, if permanent 



FIG. 543. The Argentine Ant. Left, worker; Right, wingless queen. 

 After Newell. Jour. EC. Ent. 



results are to be secured. Space here will not permit further 

 discussion of the very interesting problems arising from the 

 study of the control of this ant. 



Other Citrus Insects. 



Some of the most important citrus-fruit insects do not yet 

 occur in this country and large sums of money are spent annually 

 to keep them out by maintaining rigid quarantines. They are, 

 therefore, a source of expense to the industry, even though they 

 are not actually present. 



Among these there should be mentioned the Mexican Orange 

 Maggot ^(Trypeta ludens Loew.) and the Mediterranean Fruit 



