Tetramorium caespitum species group

Diagnosis
Agavekar et al. (2017) - Twelve-segmented antennae; anterior clypeal margin complete and unspecialized; eyes of moderate size; antennal scapes of moderate length, not surpassing posterior head margin; antennal scrobes absent; frontal carinae very short to almost completely reduced; base of first gastral tergite not concave in dorsal view, without tubercles or teeth on each side; pilosity on dorsal surfaces of body erect to suberect with long and stout hairs; sting appendage dentiform.

Tetramorium ferox species complex
Based on Csösz and Schulz 2011.

Species

 * Tetramorium aegeum
 * Tetramorium densopilosum
 * Tetramorium diomedeum
 * Tetramorium ferox
 * Tetramorium feroxoides

Identification
Key to Tetramorium ferox species complex workers

Diagnosis
Species belonging to the T. ferox-complex within the caespitum-group can be defined by the combination of the following characters.

Workers
 * petiole and postpetiole relatively broad (CS/PEW > 2.31, CS/PPW > 1.93), in T. aegeum and T. diomedeum very broad.
 * head, mesosoma and waist moderately sculptured; dorsum of both petiolar node and postpetiole medially shiny.
 * first gastral tergite smooth (excluding T. aegeum, for which 1st gastral tergite is imbricate); several long, erect hairs always appear on first gastral tergite.
 * propodeum in profile flat, sloping down at an angle of approximately 45°.
 * propodeal teeth small, developed as triangular denticles, in contrast to a prominent propodeal lobe.

Queens
 * mandibles smooth and shiny.
 * petiole and postpetiole wide.
 * mesosoma low, with flattened dorsum (seen in profile); scutum (seen from above) somewhat narrowed anteriorly and does not completely cover the pronotum, so that humeri (i. e. anterolateral pronotal angles) are easily visible.
 * head, mesosoma and waist moderately sculptured or smooth.
 * petiole and postpetiole with some very long thin hairs, in contrast to the first gastral tergite which is generally without long erect hairs.

Males
 * head and mesosoma moderately sculptured.
 * sides of petiole and postpetiole angulate in dorsal view.
 * stipes of genitalia curved inwards at the tip, and with flattened apical plate (seen in caudal view)

Tetramorium caespitum species complex
Based on Wagner et al. 2017.

See details here.

Tetramorium chefketi species complex
Based on Csösz & Schulz 2007.

Species

 * Tetramorium alternans
 * Tetramorium anatolicum
 * Tetramorium annectens
 * Tetramorium chefketi
 * Tetramorium exile
 * Tetramorium forte
 * Tetramorium moravicum
 * Tetramorium rhodium
 * Tetramorium sanetrai
 * Tetramorium sulcinode
 * Tetramorium syriacum

Diagnosis
Workers

a) polygonal striae are continuous on 1st gastral tergite, and is sometimes microreticulate basally. Polygonal striation: interstices marked by feeble anastomosing striae (Fig. 8.), compare to microreticulation: interstices marked by very feeble elevated structures, like rugulae (Fig. 6, 7.);

b) head, alitrunk and waist coarsely sculptured, dorsum of petiolar node and postpetiole coarsely rugose and/or reticulate.

c) petiole and postpetiole relatively narrow (CS/PEW and CS/PPW, Table 1);

d) ground surface on the frons is usually coarsely microreticulate;

Gynes

e) alitrunk is low, dorsum is flattened in profile;

f) scutum in dorsal view is somewhat narrowed anteriorly and does not cover completely the pronotum, humeri are well visible;

g) head, alitrunk and waist are coarsely sculptured, and petiole and postpetiole dorsum coarsely rugose or/and reticulate;

h) polygonal striae disrupted on 1st first gastral tergite, sometimes microreticulate basally;

i) mandibles are longitudinally striate;

j) petiole and postpetiole are relatively narrow (WAIST, Table 2);

Males

k) head and alitrunk with usually coarsely sculpture, ground surface microreticulate;

l) sides of petiole and postpetiole not angulate as in the ferox species complex (in dorsal view);

m) first gastral tergite usually smooth and shiny, or feebly striate;

n) stipes of genitalia blunt, curved inwards at the top, with flattened apical plate (in caudal view)

Additional Resources

 * Tetramorium
 * Tetramorium species groups