79 



Mr. Marlatt said that this work was very interesting to him 

 Ijeeaiise of the care with which the experiments had been carried on. 

 His own course had- been to try to alkiy midue enthusiasm regarding 

 the San Jose scale coccinellid. Its introduction was an experiment 

 that seemed at first promising. In many sections the experiment 

 failed, but frequently this was due to the starvation of the coccinellid, 

 l)ecaiise sulphur-lime wash was used at the same time and destroyed 

 inost of the scales. Predaceous insects of general feeding habits 

 should be introduced with care. They may destroy beneficial as Avell 

 as injurious species. Mantis, for instance, seemed to take a special 

 delight in destroying the aphid-eating coccinellid. ' 



The following paper was presented : 



REPORT ON THE "NEW ORLEANS" ANT (IRIDOMYRMEX HUMILIS 



Mayr). 



By E. S. G. Titus, Washmgton, D. C. 



In July of 1904 the Bureau of Entomology of the Department of 

 Agriculture received a letter from Prof. H. A. Morgan, of Louisi- 

 ana, inclosing a letter from Mr. E. Baker, superintendent of Audubon 

 Park, New Orleans. La. Mr. Baker's letter gave an account of an 

 ant that occurred in enormous numbers in that city and was causing 

 serious trouble. 



Lender instructions from the Entomologist, Dr. L. O. Howard, I 

 reached New Orleans from New Iberia, La., October 15. and pro- 

 ceeded to the sugar experiment station in Audubon Park. Mr. II. E. 

 Blouin, vice-director of the station, and Mr. E. Baker gave me such 

 information regarding the presence, distribution, manner of spread- 

 ing, and ravages of the ant as they had collected during the past 

 few years. 



]Mr. Baker first noticed the ants in 189(5, at which time he moved 

 into Carrollton, near the Southport docks. They then extended over 

 but a small area, reaching approximately from Southport docks to 

 Carrollton avenue and from the river back to Poplar street. At that 

 date the residents in that section had been troubled with them but 

 a short time. I could find no one who could positively remember 

 noticing them before 1895. 



In 1899 the ants were first noticed in Audubon Park, and by the 

 next summer had become quite numerous. They are now practicall}'^ 

 all over the park, the nests more common!}^ occurring at the bases of 

 trees. On the experiment-station grounds the ants' nests are very 

 common around and beneath buildings, in flower beds and cultivated 

 fields, beneath sidewalks, and even on the lawns. In wet weather, 

 Mr. Baker stated, the ants deserted their ground nests and carried 

 pupse, larvas, and eggs into the trees. Here they constructed nests by 



