THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 9 



foods of the ant derived from plant sources. 



Method of the Ant in Obtaining Plant Nectab. 



The floral, and occasionally extra-floral, nectar of many kinds of 

 plants forms the most dependable food of the ants from a direct 

 plant source. The flowers of citrus and many other cultivated and 

 wild plants are visited habitually for their nectar, which is lapped 

 up from the area around the base of the stamens and petals, this 

 area being evidently the location of the principal nectar-producing 

 glands, at least in citrus. 



With the aid of a hand lens the tube-shaped tongue of the feeding 

 ant may be seen moving rapidly and continuously, in conjunction 

 with the labial palpi, over the surface of the floral organs, while the 

 food apparently is being pushed back by a thin, elbowed member that 

 moves constantly within the tube. The ant often continues lapping 

 up the liquid until a full crop is indicated by the distended semi- 

 transparent gaster, this requiring from 15 to 30 minutes. It then 

 usually rests for a period in the flower, or it may at once start its 

 descent toward the nest. On their way down the tree forage-laden 

 ants frequently rest in any sheltered location serving to exclude 

 light and breezes, and almost invariably a group of ants resting 

 motionless may be discovered in such places along the trails. 



Ants Poisoned by Floral Nectar. 



Occasionally the ants are poisoned by the nectar from loquat 

 blossoms. On one occasion attention was attracted to a certain group 

 of blossoms by the fact that most of the ants in that neighborhood 

 were assisting sick comrades, carrying dead ants, or standing slug- 

 gishly about. Close observation of many of the last mentioned 

 showed them to have the mandibles wide open — rather an unusual 

 attitude. Under a hand lens one was seen finally to open the mouth 

 so wide that the mandibles extended at right angles to the sides of 

 the head and to regurgitate a drop of yellowish fluid. Obviously 

 it was a sick ant. It did not attempt again to feed. The loquat 

 blossom has a heavy, sweet odor peculiarly its own, but suggesting 

 that of the peach or almond, and it seems probable that at times the 

 nectar may contain traces of prussic acid. In addition to obtaining 

 the nectar from the flowers, the ant gets a good proportion of its 

 flesh food there, as will be shown later. 



Utilization of Plant Sap and Fruit Juices as Food. 



The ant also utilizes the unmodified plant sap from orange and 

 some other trees whenever it is able to obtain it. It habitually feeds 

 upon the sap from wounds in the bark and often has been observed 

 working in considerable numbers on every freshly made cut of the 



