THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 73 



phor and bottle trees (Sterculia diver si folia) and some other plants 

 in sections of Pasadena where the ants occur than in sections where 

 they do not. 



There is reason to believe that the Argentine ant may be an active 

 agent in the spread of diseases through its habit of visiting various 

 parts of the tree, and particularly freshly made wounds, for the pur- 

 pose of feeding. It appears to introduce gummosis and wood-rotting 

 fungi in this way more rapidly than could otherwise be the case. It 

 ma.j act as a conveyor of diseases of bacterial origin, such as the 

 citrus canker, by carrying the causal organisms about on its legs 

 and body. 



The control of the Argentine ant in Louisiana by the trapping 

 method described in preceding pages is entirely practicable at a 

 moderate cost. If ants are deterred by barrier ditches from entering 

 the grove rapidly, five or six fumigations about a month apart should 

 so reduce the worst infestations that annoyance from ants will cease. 

 Thereafter fumigation of a few of the traps once in every three to 

 six months will suffice to prevent further molestation. The esti- 

 mated cost of reducing the ants from most extreme numbers to the 

 few remaining where there is effective control would be about $6.03 

 per acre x for labor and fumigant, or not to exceed $16.03, including 

 the first cost of traps and covers. It is believed that large sections 

 of territory where the annual rainfall is heavy could be effectively 

 and economically freed from ants by this method if all the members 

 of the community would cooperate in the undertaking. Although 

 the labor of ant destruction might be somewhat prolonged in cities 

 because of the numerous buildings and other suitable nesting places, 

 this method, it is believed, might be advantageously adapted to city 

 use. 



Destruction of the ants in Louisiana orange groves will not effec- 

 tively control the armored scales, or the white flies and the rust mite, 

 and would not pay for itself in actual crop increase. Eegardless 

 of the ants> many run-down orange groves in Louisiana can be so 

 improved by one season's thorough spraying and cultural treat- 

 ment as almost to double their production. The success of certain 

 orchards in southern Louisiana demonstrates that oranges can be 

 profitably grown there if the trees are carefully selected and planted 

 and the best-known cultural practices and methods of insect con- 

 trol followed. The growing of citrus is a business which is in- 

 creasingly requiring thoroughgoing business methods, and this 

 applies in Louisiana as elsewhere. 



1 The term acre as used in southern Louisiana means an acre along the river front 

 by 40 acres deep, and should not he confused with the present use of the term, signify- 

 ing 160 square rods. 



