Formica omnivora
Synonymy.—The identity of this form is unknown. There are no species of Formica on Ceylon. There was another Formica omnivora described from tropical America, whose identity is also unknown (W. L. Brown, personal communication, 1956).
Natural prey.—Cockroaches, Ceylon (Kirby and Spence, 1822).
Iridomyrmex humilis Mayr
Common name.—Argentine ant.
Natural prey.—Cockroaches, injured individuals only (Ealand, 1915).
Lasius alienus (Förster)
Natural prey.—Ectobius pallidus, U.S.A., Massachusetts (Roth and Willis, 1957).
Pheidole megacephala (Fabricius)
Common name.—Big-headed ant.