8 BULLETIN 647, U. S. DEPARTMENT OF AGRICULTURE. 



fruits of the State are produced in these three parishes, so the above 

 figures give an accurate idea of the proportion of the orange groves 

 that come under the influence of the ants. The ant has not yet 

 gained an entrance into any of the seedling orange groves of Cam- 

 eron Parish. 



CALIFORNIA. 



In California the ants are present in a considerable number of 

 the groves at Riverside, Corona, Uplands, Duarte, Monrovia, Sierra 

 Madre, Alhambra, San Marino, South Pasadena, Pasadena, and 

 Altadena. They have gained a foothold in one spot in the town of 

 Pomona, but have not yet been reported in any of the orange groves. 

 When they do arrive there, however, they undoubtedly will bring the 

 mealybug into great prominence, as a minor outbreak occurred dur- 

 ing the summer of 1916, and conditions are the same there as at 

 Alhambra. They are distributed pretty thoroughly throughout 

 parts of the cities of Los Angeles and Pasadena. In Ventura County 

 they infest some of the groves at Santa Paula and occur in several 

 groves in one block at Fillmore. They have every appearance of 

 having been introduced into this section within the last three or four 

 years. In San Diego County they have not yet gained a foothold in 

 any of the orange groves, but they have been introduced into the 

 fair grounds, in the city of San Diego, where they overrun many of 

 the ornamental plants both out of doors and in the conservatories. 



FEEDING HABITS OF THE ANT. 



The damage to orange trees by the Argentine ant must be either 

 direct, through habits of feeding upon plant parts and tunneling 

 and nesting about the roots, or indirect, through its relations with 

 harmful insects and as a carrier of citrus diseases, or both. Not 

 only were the nature and amount of the injury inflicted by the ant 

 learned through a study of its foraging and nesting habits, but a 

 successful method of controlling it as well. 



It is not the intention here to specify all the foods which the ant 

 has been observed to utilize, or to describe its well-known ravages 

 into household supplies, but rather to describe its feeding habits in 

 the orange groves and particularly in their bearing upon the orange 

 trees. The ant is omnivorous, and though much of its food is de- 

 rived from plant sources, it exhibits a distinct need for animal food 

 and utilizes not only the flesh but also the excreta and other effluvia 

 of animals as well. Its need for flesh food is so marked that in the 

 artificial formicary, when flesh food is not furnished, it almost al- 

 ways will feed to some extent upon its own young. 



