18 



FARMERS' BULLETIN 928. 



borders of ornamental plants are left accessible to the ants is too slow 

 and uncertain to be of practical value. Under such circumstances 

 only a small proportion of the ants will be attracted from the natural 

 sources of focd in the trees and weeds, as they soon learn the in- 

 jurious nature of the poison and ignore it, while continuing to feed at 

 the usual near-by sources of supply. 



It is absolutely necessary, therefore, if satisfactory results are to 

 be obtained by this method, that all sources of food other than the 

 poisoned bait be eliminated so far as possible. This involves clean 

 cultivation and the banding of all trees, orange and ornamental, with 

 a mixture that will keep the ants out, Tree-banding alone in some 

 cases will cause a large proportion of the ants to migrate to another 



I 



FIG. 5. Bridges which the Argentine ants can not cross. (Newell and Barber.) 



locality in search of food and, as long as maintained, will have the 

 desired effect of preventing injury to the trees from the ants. 



Although the employment of poisoned baits in accordance with the 

 instructions given below often may prove practicable and effective 

 in ridding yards where there are comparatively f ew trees infested by 

 ants, this method can not be recommended for general orchard use in 

 Louisiana as a substitute for the trapping method. 



In preparation for the poisoning work, the premises should be 

 first freed of weeds, long grass, vines, and other plants that can not 

 be banded to keep out ants and that harbor aphids and scale insects. 

 Then all the trees should be banded in accordance with the direc- 

 tions on page 19. The ant poison then should be distributed liberally 



