METHODS OF REPRESSION. 93 



rapidly, as did the Lecaniiims, which were constantly attended by 

 the ants. The owner sprayed mdustriously with whale-oil soap, but 

 without apparent effect. During 1911 many of the trees died, and 

 at the present time (March, 1912) the orchard is practically ruined 

 and the owner has abandoned hope of saving enough trees to make the 

 orchard profitable. The condition of dying trees is well illustrated 

 by Plate VI, which shows a Louisiana Sweet orange tree that has been 

 exposed to ant infestation for three seasons. This tree stood near the 

 levee, outside the barrier ditches described below, and was exposed to 

 the work of the ants. 



Another orange orchard which we have had under close observation 

 has been mfested for 7 years, and during this time no measures have 

 been taken to control the ants. In this orchard fully 60 per cent of 

 the trees are dead and the remammg trees are heavily incrusted \^dth 

 both the chaff scale and the purple scale (Lepidosaplies heckii Newm.). 

 So abundant are the ants here that a bit of earth disturbed by one's 

 foot at any point in the orchard will reveal a seething mass of ants. 

 A recent crop from this orchard consisted of but 250 boxes of inferior 

 quality. Other orchards, of approximately the same sixe but not yet 

 infested by the ant, produced in the neighborhood of 3,000 boxes. 

 At Soccola Canal there is a small tract of land on which four orange 

 orchards have been planted m succession, all of which have died before 

 reaching bearmg age. The entii'e neighborhood is heavily mfested, 

 and Mr. S. M. O'Brien, of Nairn, La., states that to his knowledge the 

 ants have been abundant at Soccola for at least 17 years. The plat 

 has now been entii'ely abandoned as an orange grove, the last of the 

 dead orchards having been removed during 1911 and the land devoted 

 to the growmg of truck crops. 



METHOD OF DISSEMINATION IN THE ORANGE SECTION. 



As already indicated, the most probable sources of original infesta- 

 tions in the orange section were drifting logs in the river, these logs 

 carrymg living colonies of the Argentine ant. In times of flood these 

 logs are thrown up on the batture (the space between the river bank 

 and the levee) and remain there in large numbers. It is the history 

 of practically all infestations in this section that the ants first appeared 

 on the batture, then along the levee, and from the latter worked their 

 way back from the river. At all the infested points the levee is found 

 to be teemhig with the ants and the batture itself is a constant breed- 

 mg place. A portion of the infested batture, covered with a thick 

 growth of willows, is shown in Plate IX. Here the ant colonies are 

 found under eveiy particle of driftwood and trash, and during almost 

 the entire year they are in attendance upon Coccidse and Aphididse 

 on the willows. For a number of weeks each year this batture is 

 covered with several feet of water from the river, but the infestation 



