Simopone Forel, 1891

Eguchi, Katsuyuki, Viet, Bui Tuan & Yamane, Seiki, 2014, Generic Synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part II — Cerapachyinae, Aenictinae, Dorylinae, Leptanillinae, Amblyoponinae, Ponerinae, Ectatomminae and Proceratiinae, Zootaxa 3860 (1), pp. 1-46 : 19-20

Simopone Forel, 1891

Taxonomy. The genus Simopone is assigned to the tribe Cerapachyini together with Cerapachys and Sphinctomyrmex ( Bolton 2003) . Definition of the genus was revised by Bolton and Fisher (2012).

Morphology. Although no Vietnamese specimens of this genus were examined in the present study, according to Radchenko (1993b) and Bolton & Fisher (2012), workers of a known Vietnamese species of this genus ( S. oculata Radchenko ) may show the following features:

Head in full-face view elongate, with sides almost parallel, without a differentiated vertical posterior surface above occipital foramen (instead vertex slopes evently down to upper margin of occipital foramen); preoccipital carina distinct; frontal lobe not vertically raised, in full-face view concealing at least inner margins of antennal sockets; the lobes relatively widely separated from each other by posteromedian portion of clypeus; frontal carina reaching dorsal margin of eye; parafrontal ridge almost reaching anterior margin of eye; mandible subtriangular, armed with minute teeth on masticatory margin; antenna 11-segmented; scape clavate, short; segment II to apical segment short and gradually incrassate; eye large; ocelli present but minute; mesosoma elongate with its dorsolateral borders right-angled; pronotum marginate anteriorly; promesonotal suture represented by transverse trace dorsally but distinct laterally; metanotal groove poorly visible dorsally but distinct laterally; mesotibia without spurs (at most a setiform vestige may remain that cannot be distinguished by light microscopy from other setae at tibial apex); metatibia with a single pectinate spur; metabasitarsus ventrally with a longitudinal glandular groove that occupies at least basal half of tarsomere length; pretarsal claws of all legs with a single preapical tooth on inner margin; propodeum unarmed, but posterior face margined dorsally and laterally with a distinct ridge; petiole in lateral view elongate and compressed dorsoventrally, with a transverse anterior carina.

Differentiation. The worker of Simopone is similar to that of Cerapachys , but in the latter the frontal lobes are very narrowly separated from each other by a longitudinal strip of the median portion of clypeus, the antennal socket is in full-face view almost completely exposed, and one or two tibial spurs are present on middle legs.

Vietnamese species (1 sp.).

Simopone oculata Radchenko, 1993 . Type locality: Kondor Island [Con Son I., Ba Ria-Vung Tau Prov.].

Bionomics. Radchenko (1993b) mentioned that the holotype (worker) of S. oculata was collected under a stump in a secondary tropical forest, but the life history of the species is unknown.