Tetraponera hysterica (Forel)

Ward, Philip S., 2022, The ant genus Tetraponera (Hymenoptera: Formicidae) in the Afrotropical region: taxonomic review and key to species, Zootaxa 5102 (1), pp. 1-70 : 39-40

Tetraponera hysterica (Forel)

( Fig. 17 )

Sima hysterica Forel 1892: 258 . Syntypes, 3 workers, Village de Nosibé , Imerina, Madagascar (Sikora) ( MSNG, MHNG) [examined] . 2 syntype workers from MHNG imaged on AntWeb: CASENT0101635, CASENT0101941 . 1 syntype worker from MSNG imaged on AntWeb: CASENT0102034 .

Sima Sahlbergi var. inflata Emery 1899a: 273 . Syntypes, 4 workers, Baie d’Antongil , Madagascar (Mocquerys) ( MSNG, MHNG) [examined] . 1 syntype worker from MHNG imaged on AntWeb: CASENT0101575. Syn. nov .

Sima (Tetraponera) hysterica Forel ; Emery 1921: 27. Combination in Sima (Tetraponera) .

Tetraponera hysterica (Forel) ; Wheeler 1922c: 1015. Combination in Tetraponera .

Tetraponera hysterica (Forel) ; Chomicki et al. 2015: figure S1. Placement in molecular phylogeny.

Sima hysterica var. inflata Emery ; Forel 1904: 376. Variety of S. hysterica .

Sima (Tetraponera) hysterica var. inflata Emery ; Emery 1921: 27. Combination in Sima (Tetraponera) .

Tetraponera hysterica var. inflata (Emery) ; Wheeler 1922c: 1015. Combination in Tetraponera .

Tetraponera hysterica inflata (Emery) ; Ward 1990: 488. Subspecies of T. hysterica .

Worker measurements (n = 9). HW 0.73–0.89, HL 0.96–1.22, LHT 0.77–0.92, CI 0.71–0.76, FCI 0.14–0.17, REL 0.25–0.29, REL2 0.34–0.38, SI 0.60–0.67, SI3 1.63–1.93, FI 0.39–0.44, PLI 0.63–0.69, PWI 0.48–0.56, LHT/HW 0.96–1.06, CSC 0–4, MSC 7–14.

Worker diagnosis. Moderate-sized species, with somewhat elongate head and small eyes (see ocular indices); minimum distance between frontal carinae exceeding basal scape width (FCI 0.14–0.17); scape moderately long, notably more than one-half head width and about one-half head length (SI 0.61–0.64, SI2 0.45–0.51); median clypeal lobe crenulate, with a weak (or absent) median tooth, two slightly larger but blunt lateral teeth, and outer lateral teeth reduced to slight protrusions or absent ( Fig. 17a ); profemur moderately robust (FI 0.39–0.44); mesosoma with a differentiated, transverse metanotal plate, about one third the length of the mesonotum; metanotal plate with a weak median groove; dorsal face of propodeum laterally submarginate, longer than declivitous face and rounding insensibly into the latter; petiole moderately robust (see PLI and PWI values), with a differentiated anterior peduncle and anteroventral tooth, the node with steep anterodorsal face and shallower posterodorsal face ( Fig. 17b ); postpetiole longer than broad. Integument shiny to sublucid, with weak reticulation and scattered punctures, the punctures moderately coarse on the head, finer elsewhere. Standing pilosity sparse on head, with 0–2 (usually 1) supraocular pair of setae, more common on mesosoma (MSC 7–14) but absent from dorsal face of propodeum. Dark brownish-black, antennae and mandibles lighter.

Comments. The key features of Tetraponera hysterica workers are the relatively small eyes and elongate head (such that REL2 0.34–0.38 and CI 0.71–0.76), crenulate (as opposed to conspicuously toothed) median clypeal lobe, short metanotal plate with median furrow, and dark brownish-black coloration. Tetraponera hysterica is superficially similar to T. longula , another dark-colored rainforest species, but T. longula workers have conspicuous clypeal teeth, more closely contiguous frontal carinae (FCI 0.09–0.12) and a more slender petiole (PLI 0.46–0.57) without a well developed anteroventral tooth. T. hysterica is actually more closely related to a group of dry forest species that includes T. morondaviensis and T. perlonga ( Chomicki et al. 2015) , differing from them by its darker coloration, submarginate propodeum, medially furrowed metanotal plate, and details of pilosity, head shape and clypeal dentition.

Distribution and biology. T. hysterica is a rather uncommon rainforest species, known from scattered locations along the east coast of Madagascar, from 14°S to 25°S. It appears to be a generalist inhabitant of dead twigs.

Figures

FIGURES 16–18. Tetraponera allaborans group, workers, full-face (dorsal) view of head (a) and lateral profile of body (b). 16, T. tessmanni, Cameroon (CASENT0794354); 17, T. hysterica, Madagascar (CASENT0012842); 18, T. longula, Madagascar (CASENT0012843). Images from AntWeb (www.antweb.org); photographers Matthew Prebus (16), April Nobile (17, 18).