Tetramorium Mayr

Eguchi, K., Viet, B. T. & Yamane, S., 2011, Generic synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part I - Myrmicinae and Pseudomyrmicinae., Zootaxa 2878, pp. 1-61 : 30

Tetramorium Mayr , 1855

Taxonomy. The genus Tetramorium is assigned to the tribe Tetramoriini (for a complete taxonomic history see Bolton 2003). The Oriental species were revised by Bolton (1976, 1977). Workers of Vietnamese species have the following features.

Worker monomorphic; head in full-face view subrectangular, with rounded posterior corners; frontal carina usually (but not always) long and distinct; antennal scrobe weak or absent; anteromedian margin of clypeus weakly convex, often with a weak emargination at midpoint, lacking any denticles or teeth; an isolated median seta absent; posteromedian portion of clypeus very broadly inserted between frontal lobes; lateral portion of clypeus modified into a distinct ridge or wall in front of antennal insertion; mandible triangular; masticatory margin with apical and 1 or 2 larger preapical teeth followed by some smaller teeth or minute denticles; palp formula 4,3; antennae 11- or 12-segmented, with 3-segmented club; basal rim of shaft of antennal scape often forming an enlarged lobe expanding ventrad; eye medium to large in size; mesosoma in lateral view weakly convex dorsad; promesonotal suture absent dorsally; metanotal groove absent; anterior part of mesopleuron forming a flange projecting over basal part of fore coxa; propodeal spine present, varying in size and shape; propodeal lobe well developed usually as a triangular lamella or spinose projection but sometimes as a subrectangular or round lamella; petiole pedunculate, with distinct node; a tiny denticle or process present on the anteriormost part of ventral face of peduncle (it is often concealed by mesopleuron and or hind coxa in lateral view); gastral shoulder distinct to absent; apex of sting with a small lamellate appendage; head and mesosoma usually strongly reticulate or rugoso-reticulate.

The worker of Tetramorium is similar to those of Rhoptromyrmex and Myrmica (for distingusihing characters see under the latter genera)

Vietnamese species. Four species have been described from Vietnam: indosinense Wheeler [= sp. eg-13] (Type locality: Ha Noi; other locality: Ba Vi); infraspinosum Karaviev (type locality: Cau Da); kieti Roncin (type locality: Vietnam); secure Roncin (type locality: Vietnam). An additional 21 species have recognized by us from Vietnam: flavipes Emery [= sp. eg-4; = sp. 39 of SKY: Yamane et al., 2003] (Ba Vi, Chua Yen Tu, Cuc Phuong, Nam Cat Tien, Phu Quoc, Pu Mat, Tay Yen Tu, Van Ban); kheperra (Bolton) [= sp. eg-9] (Ba Vi, Phu Quoc, Tay Ye n T u); lanuginosum Mayr [= sp. eg-17] (Ba Vi, Bac Kan, Tam Dao); nipponense Wheeler [= sp. eg-5] (Ba Be, Ba Vi, Cuc Phuong, Sa Pa, My Yen, Pu Mat, Tay Yen Tu, Van Ban); sp. eg-1 (Sa Pa); sp. eg-2 [= kraepelini Forel : Eguchi et al., 2005] (Ba Vi, Nam Cat Tien, Phu Quoc, Pu Mat, Tay Yen Tu); sp. eg-3 [= sp. 32 of SKY: Eguchi et al., 2005] (Ba Vi, Chua Yen Tu, Tam Dao, Tay Yen Tu, Van Ban); sp. eg-6 [cf. pacificum Mayr ] (Sa Pa, Pu Mat); sp. eg-7 (Sa Pa); sp. eg-8 (Ba Be); sp. eg-10 (Tay Yen Tu); sp. eg-12 (Ba Vi, Pu Mat); sp. eg-14 (Binh Chau-Phuoc Buu); sp. eg-15 [= bicarinatum (Nylander): Eguchi et al., 2005] (Tam Dao); sp. eg-16 [= smithi Mayr : Eguchi et al., 2005] (Ba Vi); sp. eg-18 [= walshi (Forel): Yamane et al., 2003] (Cuc Phuong, My Yen, Pu Mat); sp. eg-19 (Ba Be); sp. eg-21 (Cuc Phuong); sp. eg-22 (Nam Cat Tien); sp. eg-23 (Nam Cat Tien, Nui Chua); sp. eg-24 (Nam Cat Tien).

Bionomics. Tetramorium species inhabit various habitats such as open lands, grasslands, forest edges and well-developed forests. Their nests are usually found in rotting logs, twigs, wood fragments, under stones and in soil. Workers forage mainly on the ground.