BEHAVIOR OF ANTS 419 



the wasps and bumble-bees, but more indirectly and obscurely 

 in the honey-bees, ants, and termites. The disappearance of the 

 worker phases in certain small and permanently parasitic ants 

 like Anergates atratiilus is explained as the result of overfeeding 

 of all the female larvas, coupled with their small size, and not 

 as due to the uselessness of the worker caste. 



Jacobson °' describes the habits of a well-known Indomalayan 

 ant, Pheidologeton diversus, and of a singular flly, Bengalia latro, 

 which deprives it of its food. The Pheidologeton has highly 

 polymoiphic workers, varying from small individuals with small 

 heads to huge soldiers with large heads and mandibles. The 

 species is omnivorous, eating both insects and seeds. It forages 

 in long files which construct beaten roads from the crater nest, 

 or even covered galleries 2-2.5 cm. broad and sometimes 50 m. 

 long. The large soldiers rarely accompany the files of workers, 

 but will defend the nest w^hen it is broken open. They also 

 probably husk the seeds which are carried into the nest by the 

 small workers. The Bengalia stations itself near a file of forag- 

 ing ants and pounces on the workers as they return laden with 

 food, wresting it from them with great skill and celerity and 

 devouring it, if it is of animal nature, but rejecting it if it is 

 vegetable. According to Jacobson the fly can see a food-laden 

 ant at a distance of at least 15 cm. The Bengalia and two other 

 Diptera (Idia luteigaster and /. discolor), which hang about the 

 Pheidologeton nests, but without revealing their intentions, are 

 described in a separate paper by de Meijere -\ 



Kneissl ""', after giving an interpretation of the synonymy of 

 the peculiar myrmecophilous mite Uropolyaspis hamuliferus, 

 records several observations on its behavior. As a nymph it is 

 invariably attached to the basal edge of the tibia of one of the 

 middle or hind feet of Lasius niger by means of an anal secretion, 

 in such a position that the anterior end is always turned out- 

 ward and slightly upward with respect to its host. Here it 

 sheds its skin and becomes an imago. In this stage its food 

 is unknown but probably consists of offal; during its nymphal 

 stage, however, it is licked and fed by the ants. Its transforma- 

 tion, according to Kneissl, depends on the frequency with which 

 it is licked. The imago is regarded as a synoekete, the nymph 

 as a " pseud osymphilic ectoparasite." Attention is called to 

 a singular organ situated between the anus and fourth pair of 



