264 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



on itself and runs toward coxa II. Female genital aperture not quite reach- 

 ing the camerostome, and behind hardly extending to coxa IV. Male genital 

 aperture one and one-fourth times longer than broad, and still farther from 

 the camerostome. Legs of moderate length; the tarsi quite slender, I with 

 many bristles hear tip, one of them as long as the tarsus, other tarsi with 

 short spines, the hind tarsus fully as long as space between hind coxae. 

 Length 1. mm. 



"Baton Rouge, La.; associated with the Argentine ant." 



For the purpose of determining the habits of these mites and the 

 part played by them in the economy of the ant colonies, several hun- 

 dred were placed in a colony of the Argentine ants, confined in a 

 modified Janet cage, cast of plaster of Paris and containing five 

 chambers, four of Avhich connect with each other by means of small 

 tunnels, the fifth chamber being for the reception of water to main- 

 tain humidity in the nest. In a cage of this character one chamber, 

 usually the one furthest from the entrance, is invariably "set aside" 

 by the ants as a cemetery, in which all dead individuals, refuse matter 

 from the nest, etc., is deposited from time to time. It has been our 

 custom to leave the chamber nearest the entrance covered only with 

 glass, to form a sort of "vestibule" to the nest proper. 



Fine trash, containing eggs, larva and pupa? of the Argentine ant 

 as well as hundreds of the two species of mite were placed in the 

 vestibule of one of these cages on March 11th. The workers imme- 

 diately selected all ant larva?, eggs, and pupae from the trash and car- 

 ried them into the nest proper, paying no attention to the Uropodas 

 and neither attempted to destroy them nor carry them into the nest. 

 The vestibule, or outer cham])er. was by far the dryest compartment 

 and during the two following days the Uropodas which failed to find 

 their way through the small tunnel into the nest proper perished, 

 either of starvation or lack of moisture. On the third day following 

 their introduction, some of the living mites were in the nest with the 

 workers and young, but the great majority had found their way 

 through the two living chambers and three tunnels to the back cham- 

 ber or "cemetery," where they were feeding upon the refuse matter 

 placed there by the ants. Since that date, a period of about 100 days, 

 the mites have continued to thrive in this colony. The mites never 

 attack the immature stages of the ant nor do they seem to cause any 

 annoyance or inconvenience to the latter. The ants, for their part, 

 seem to be entirely indifferent as to the welfare of the mites. They 

 never attempt to remove them or care for them, but appear to regard 

 them with a spirit of kindly toleration. Observations made upon 

 these mites in other colonies but served to verify these conclusions. 

 In the case of one Janet cage the solvent action of the water, which 



