THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 65 



EFFECT OF CORROSIVE SUBLIMATE. 



A poisonous emanation appears to be given off by the mercuric 

 hellac band which is very injurious to the ants, as one example of 

 lie behavior of ants which have crossed it will illustrate. An ant 

 ttempting to cross one of these bands suddenly stopped when part 

 7&y across and began to stroke the antennae with the first pair of 

 3gs. It remained on the band about 1^ minutes, turning slowly 

 bout, stroking the antennae, and drawing the legs between the 

 landibles. It then slowly retraced its steps off the band and moved 

 imlessly about for a time, often getting in the way of other ants. 

 Joon one of these stopped and took hold of one of its antennae. 

 ?his made it active long enough to disengage itself, when it again 

 ecame sluggish and wandered aimlessly. This continued as long 

 s it was watched — about 10 minutes. Other ants, some of which 

 rare themselves *sick, were trying to drag their dizzy fellows to a 

 tielter. Most of the sick ants finally became very sluggish and many 

 f them fell from the tree. 



TRAPPING THE ARGENTINE ANT IN LOUISIANA. 



By far the best and the only practical means of destroying the 

 Lrgentine ant in the orange groves of Louisiana is by trapping, 

 ^he discovery that the ants would collect in large numbers in boxes 

 f decaying vegetation in winter was first made by Messrs. Newell 

 nd Barber, who described a method of destroying them based on 

 his fact. 1 The method of trapping about to be described differs 

 n several important respects, however, from that recommended by 

 hese gentlemen. It is based mainly upon the fact that a very slight 

 ain at any season of the year will cause the ant colonies to come out 

 f the ground, where most of them nest, and seek dry, sheltered 

 •laces. 



Effect of Rains Upon the Ants. 



The favorite rainy-weather nesting places of the ants are under 

 oose boards, piles of lumber, boxes, logs, sacks, and pieces of cloth, 

 >iles of bricks, piles of dead weeds, under and in the sides of build- 

 rigs, etc. They also preferably seek high ground, and, other condi- 

 ions being equal, the largest colonies will be found on the ditch 

 ianks and the high ground at the base of the trees. Just as foraging 

 workers often complete a partial natural shelter found upon a tree 

 ir elsewhere by making walls of bits of trash, the ants often build 

 daborate structures of soil particles and trash under the loose boards 

 md other shelters found on or near the ground. 



The idea of using the traps about to be described was first sug- 

 gested by the behavior of the ant colonies in an orange orchard in 



*Op. cit., p. 95-96. 



