Feb. '08] JOURNAL OF ECONOMIC ENTOMOLOGY ^ 



It is in its relationship to the cane growing industry that /, humilis 

 promises to be of most importance. "Wherever this ant has become 

 exceedingly abundant in the cane fields a mealy-bug locally known as- 

 the " poo-a-pouche " increases with great rapidity. This latter insect 

 has been identified by Mr. J. G. Sanders of the Bureau of Entomology 

 as Pseudococcus calceolariae (Mask). Not only does the poo-a-pouche 

 heavily infest the growing cane, finding lodgment between the leaf 

 and the cane itself and drawing heavily upon the sap, but in the 

 spring of the year it is apparently colonized upon cane underground 

 by Iridomyrmex humilis, and there it proceeds to destroy the germ- 

 inating buds of the "plant cane." By way of parenthesis I should 

 perhaps explain that one of the methods of propagating sugar cane is 

 to plant the previous year's canes in rows during the winter and the 

 bud at each joint develops the following spring, sending up a rapidly 

 growing shoot. By the destruction of these developing buds below the 

 surface of the ground in spring, the prospective cane crop is as com- 

 pletely destroyed as would be a crop of corn were some insect to de- 

 vour all of the seed planted. 



Mr. J. B. Garrett, of the Louisiana Experiment Stations, who has 

 recently been making a study of this poo-a-pouche, finds that its dis- 

 tribution is by no means co-extensive with that of the ant, and that it 

 occurs only in a small part of the territory now occupied by the latter. 

 The poo-a-pouche occurs in destructive numbers on the plantations 

 from New Orleans to the mouth of the Mississippi River, a distance of 

 ninety miles. The fact remains, however, that this is the territory in 

 which the ant is most numerous and most firmly established. 



Mr. Garrett also expresses doubt as to the ant actually colonizing 

 the poo-a-pouche upon the cane, and suggests at the same time that 

 the unusual increase of the poo-a-pouche may be due to protection 

 from its natural enemies, afforded by the ants. It happens that the 

 varieties of cane most susceptible to this injury are among the best 

 ones at present grown in the South. Unless some unforeseen factor 

 injects itself into this problem, the entire sugar industry of the South 

 will be threatened by this poo-a-pouche and the attending Argentine 

 ant, which seems to be responsible for its rapid increase. 



An interesting food habit of this species has become apparent to 

 truck growers. The workers are very fond of lettuce seed and while 

 we are not as yet certain that the lettuce seed are harvested from the 

 mature plants, it is well established that the workers industriously 

 dig up and carry to their nests freshly planted seed from the gar- 

 dener's beds. In the infested territory some expedient has to be 

 resorted to to protect the lettuce seed until they germinate, by which 

 time they are safe from the attacks of this ant. The workers are fond 



