The species described as new is placed in the genus Adelencyrtus, Ashmead, provisionally. The description is published at this time to provide a name, so that biological information concerning the species can be made a matter of record. The new species is most closely allied to Adelencyrtus. It differs from typical species of this genus with regard to the mandibles. In typical Adelencyrtus the mandibles are quadridentate, and the ventral margin is provided with a stout, cone-shaped seta. In the new species only the ventral tooth is distinct; the dorsal margin of the cutting edge appears as a wide truncation, which can scarcely be described as subdivided, and the ventral margin of the mandible lacks the stout conical seta. The most useful character for the identification of this species, and the one which reveals its relationship to Adelencyrtus most surely, is the distinctive male antennae. In this sex the antennal club is enormously cylindrically elongated, and the funicle is composed of two vestigial segments that are contained in a recess at the base of the club. Antennae of a similar kind have been described in the males of Habrolepis, Förster and Anabrolepis, Timberlake, two genera which are closely allied to Adelencyrtus. The males of Adelencyrtus have not been described.