Aenictus silvestrii

Jaitrong, Weeyawat & Yamane, Seiki, 2011, Synopsis of Aenictus species groups and revision of the A. curra x and A. laeviceps groups in the eastern Oriental, Indo-Australian, and Australasian regions (Hymenoptera: Formicidae: Aenictinae), Zootaxa 3128, pp. 1-46 : 10

Aenictus silvestrii group

Diagnosis. Antenna thick, consisting of only 8 or 9 segments; scape somewhat flattened, broadened apically and strongly grooved below. Anterior clypeal margin roundly convex in the middle, without denticles. Mandible triangular, with very dense small punctures; its masticatory margin with inconspicuous denticles in addition to the sharp apical tooth. Frontal carinae fused at the level of antennal base to form a single carina; parafrontal ridge absent. Occipital margin forming a narrow collar. Declivity of propodeum concave, encircled with a rim; subpetiolar process weakly to well developed. Legs relatively short, with apical half of tibia weakly broadened and apical half of femur strongly broadened and somewhat flattened.

Head entirely sculptured but in one species smooth. Gastral segment I entirely smooth and shiny except the base of tergite I and sternite I which has dense small punctures; the punctured area usually dark colored. Head and mesosoma yellowish, reddish or dark brown; gaster paler, usually yellow; typhlatta spot absent.

Remarks. This is a unique group, which has the antenna with less than 10 segments. The groove on the ventral face of the scape, which is strongly flattened, and the enlarged femora of the legs are also useful for recognizing this group.

Distribution. Thailand, Malay Peninsula (W. Malaysia), Sumatra, Borneo (Sabah, Sarawak, and Brunei), and W. Java.

Currently valid names for the Oriental, Indo-Australian, and Australasian forms. A. glabratus Jaitrong et Nur-Zati, 2010 ; A. jarujini Jaitrong et Yamane, 2010 ; A. latifemoratus Terayama et Yamane, 1989 ; A. silvestrii Wheeler, 1929 .