RELATIONS WITH OTHER ARTHROPODA. 69 
tion of the plants by the " cotton louse," Aphis gossypii Glov., 
throughout the entire growing season. 
Were the jaws of the Argentine ant powerful enough to pierce the 
cotton squares so that they could remove the boll-weevil larvae, and 
were they so inclined, they might be of substantial service in destroy- 
ing this pest. However, repeated experiments made by the senior 
author proved conclusively that the ants would not do this. The 
following experiment will serve as an illustration of those carried out: 
On July 10, 1908, three weevil-infested squares were placed on the 
food table of an Argentine-ant colony in the insectary at Baton Rouge. 
The workers crawled over them constantly for three hours, but made 
no attempt to bite into them and evidently did not suspect the pres- 
ence of food inside of them. Afterwards the weevil larvae were re- 
moved from the squares and placed, alive and uninjured, on the food 
table. The ants attacked them, hesitatingly at first and then with 
avidity, and in the course of a minute one large weevil larva was 
dragged an inch across the food table, vertically another inch, and 
into the vestibule of the nest. Another lot of weevil-infested squares 
was placed on a board inside the insectary where the ants had been 
securing other food for several days. The squares were left here for 
five hours, during which time the ants crawled over them constantly, 
but made no effort to open them. The ends of the squares were then 
broken off so that the ants could enter them if they chose. None 
entered. Presently some of the weevil larvae wriggled themselves 
completely out of the squares and they were then attacked by the ants 
and dragged away. 
These and similar experiments lead one to the conclusion that the 
Argentine ant will never be of material value as an enemy of the boll 
weevil. In fact, in this respect it can not hope to appro acli in effi- 
ciency the common native fire ant, Solenopsis geminata Fab. 
BENEFICIAL ASPECTS OP THE ANT's ACTIVITIES. 
In some few cases the predatory habits of the ant take on a bene- 
ficial aspect. In the summer of 1908 Mr. R. C. Treherne was associ- 
ated with us in the investigation of the sorghum midge (Diplosis) 
Contarinia sorgJticoIa Coq. In the course of his work Mr. Treherne 
placed heads of sorghum, milo maize, etc., in cages for the purpose of 
rearing the adult midges. In a very short time he found that the 
Argentine ants were invading the cages and were carrying away the 
adult midges almost as fast as they emerged. (See Rg. 10, from draw- 
ing by Mr. Treherne.) To continue the observations it was necessary 
to isolate the cages over trays of water or oil. For the purpose of 
more closely observing the capture of the midges by the ants, about 
200 of the former were placed inside a large glass bell jar. The jar was 
raised a trifle at its lower edge by the insertion of a match. In the 
