Tetramorium tortuosum species group

The Tetramorium tortuosum group is widely distributed in the New and Old World with its main diversity centered in the Malagasy, Oriental and Indo-Australian regions.

Diagnosis Eleven-segmented antennae; anterior clypeal margin medially impressed; frontal carinae well-developed and usually running to posterior head margin; anterior face of mesosoma weakly developed; margination between lateral and dorsal mesosoma generally well-developed; propodeal spines always long to extremely long, spinose, and acute (PSLI 28–72); propodeal lobes usually well-developed, triangular to elongate-triangular, generally short and acute, rarely strongly reduced to almost absent; petiolar node rectangular nodiform, anterodorsal and posterodorsal margins usually well-defined, anterior and posterior faces often parallel, node longer than wide in most species, broader than long in few species; postpetiole usually globular to subglobular; mandibles strongly sculptured in most species; head and mesosoma with distinct and predominantly longitudinally rugose sculpture; waist segments with distinctly rugose, rarely rugulose, sculpture; gaster unsculptured, smooth and shiny in many species, but sculpture present on the first gastral tergite in several species; in most species all dorsal surfaces of head, mesosoma, waist segments and gaster with abundant, long, standing hairs; sting appendage spatulate. (Hita Garcia and Fisher 2012)

This group can be arranged into the following species complexes:

Tetramorium andrei species complex

 * Tetramorium ala
 * Tetramorium andohahela
 * Tetramorium andrei
 * Tetramorium electrum
 * Tetramorium elf
 * Tetramorium isectum
 * Tetramorium isoelectrum
 * Tetramorium nify
 * Tetramorium voasary

Tetramorium capillosum species complex

 * Tetramorium capillosum
 * Tetramorium hecate
 * Tetramorium tabarum

As defined by Hita Garcia and Fisher (2013).

Afrotropical. A moderately restricted distribution range, all 3 species are known from Equatorial rainforests in the Central African countries of Gabon, Cameroon, Democratic Republic of Congo, Central African Republic, and Uganda.

Diagnosis

Eleven-segmented antennae; antennal scape short to moderately long (SI 73 - 86); anterior clypeal margin usually entire without median notch; frontal carinae very well developed and usually reaching posterior head margin; antennal scrobe present, weakly to very well developed; propodeal spines medium-sized to long, elongate-triangular to spinose; propodeal lobes short, triangular to elongate-triangular; petiolar node in profile nodiform, in profile as high as long to 1.3 times higher than long (LPeI 78 - 100), in dorsal view always longer than wide (DPeI 80 - 93); postpetiole sub-globular to moderately anteroposteriorly compressed; mandibular sculpture variable; cephalic sculpturation distinct, between frontal carinae longitudinally rugose to reticulate-rugose; mesosoma predominantly longitudinally rugose; petiolar node weakly to distinctly rugose, postpetiole ranging from unsculptured to longitudinally rugose; gaster unsculptured, smooth, and shiny; all dorsal surfaces of body with abundant, long, standing hairs; first gastral tergite without pubescence and pilosity never short, dense, and appressed; sting appendage spatulate.

Identification

In the Afrotropical region, members of the T. tortuosum group are unlikely to be misidentified with species from the other three groups having 11-segmented antennae. The 26 species of the T. weitzeckeri group all have a squamiform or high nodiform petiolar node, which is always significantly wider than long. This node shape strongly contrasts with the shape observed in the T. tortuosum group since all three members have a nodiform node which is much longer than wide. The second species group, the T. angulinode group, is morphologically closer to the T. tortuosum group since both groups share a nodiform petiolar node. However, they can be clearly separated by the pilosity/pubescence patterns on the first gastral tergite. In the T. tortuosum group pubescence is absent and pilosity is long and mainly erect, whereas in the T. angulinode group pubescence and pilosity are usually present, dense, appressed to decumbent, and often pointed towards a longitudinal midline of the tergite. The synonymisation of Triglyphothrix under Tetramorium (Bolton 1985) added an additional group, the T. ericae group, with few species that possess 11-segmented antennae. However, these species are all comparatively small and have branched pilosity on most of the body, thus not easily confused with the much larger T. tortuosum group species that all possess simple pilosity.

Tetramorium jedi species complex

 * Tetramorium avaratra
 * Tetramorium jedi
 * Tetramorium pleganon

Tetramorium noeli species complex

 * Tetramorium aherni
 * Tetramorium ambanizana
 * Tetramorium noeli
 * Tetramorium singletonae

Tetramorium smaug species complex

 * Tetramorium adamsi
 * Tetramorium marojejy
 * Tetramorium latreillei
 * Tetramorium nazgul
 * Tetramorium sabatra
 * Tetramorium smaug