Temnothorax rufus Prebus

Prebus, Matthew, 2015, Palearctic elements in the old world tropics: a taxonomic revision of the ant genus Temnothorax Mayr (Hymenoptera, Formicidae) for the Afrotropical biogeographical region, ZooKeys 483, pp. 23-57 : 39

Taxon classification Animalia Hymenoptera Formicidae

Temnothorax rufus Prebus sp. n. Figs 2b and d, 4c, 12

Type material.

Holotype worker, KENYA, Kora National Park, "Salvadora pitfall", collection code no. 18, 1983 N.M. Collins & M. Ritchie (BMNH: CASENT0712675). Paratype, 1 worker with same data as holotype (HLMD: CASENT0733784).

Diagnosis.

Temnothorax rufus is easily distinguishable from the other Afrotropical species by the following character combination:

Antennal scapes surpassing the posterior margin of the head by the length of the first two funicular segments; postpetiole widest at the anterior 1/3 of the segment;posterior margin of head rounded; promesonotal suture shallowly impressed; compound eyes moderate in size; propodeal spines moderately long.

Worker measurements

(n = 2). EL 0.162-0.164 (0.163); FRS 0.191-0.196 (0.194); HL 0.654-0.664 (0.659); HW 0.517-0.527 (0.522); IOD 0.446-0.455 (0.451); IOcD N/A; MD 0.167-0.18 (0.174); PH 0.19-0.213 (0.202); PL 0.286-0.299 (0.293); PPH 0.21-0.222 (0.216); PPL 0.204-0.211 (0.208); PPW 0.257-0.278 (0.268); PTW 0.156-0.176 (0.166); PW 0.375-0.386 (0.381); SL 0.626-0.633 (0.63); SPST 0.169-0.177 (0.173); WL 0.863-0.868 (0.866).

Indices: CI 79.1-79.4 (79.2); DPeI 54.5-58.9 (56.7); DPpI 122-136 (129); LPeI 140-151 (145); LPpI 91.9-100.5 (96.2); OI 31.1-31.3 (31.2); PeNI 41.6-45.6 (43.6); PpNI 68.5-72 (70.3); PPI 158-165 (161); PSLI 25.8-26.7 (26.2); SI 94-96.8 (96).

Worker description.

Head longer than wide (CI 79.1-79.4); head sides parallel, but converging toward the mandibular insertions anteriorly beyond the level of the antennal insertions in full-face view; posterior head margin broadly convex and posterior corners of head broadly rounded. Anterior clypeal margin convex, with the median clypeal lobe projecting slightly beyond the lateral clypeal lobes. Frontal carinae developed: extending posteriorly to about midlength of the compound eye, after which they become indistinguishable from the ground rugulae of the head. Antennae 12-segmented,antennal scapes long, surpassing the posterior margin of the head by about the length of the first two funicular segments (SI 119-122). Eyes moderate in size (OI 31.1-31.3), 11 ommatidia in longest row.

Mesosoma relatively slender (WL 1.31-1.32 times HL); promesonotal suture not impressed. Metanotal groove shallowly impressed; visible as a broad, shallow concavity in lateral view. Propodeal spines acute and moderately long (PSLI 25.8-26.7); propodeal lobes small and rounded.

Petiole without a differentiated peduncle. In profile, petiole with a low carina running transversely from the petiolar spiracle to the posterior margin; the anterior face of node forming a shallow concavity anteriorly as it joins the anterior portion of the petiole. Petiolar node in profile relatively low, with anterior and posterior faces broadly rounded (LPeI 140-151). In dorsal view petiole elongate (DPeI 54.5-58.9). Postpetiole in profile globular, nearly equal in height to petiolar node and relatively elongate (LPpI 91.9-100.5); in dorsal view transversely elongate-oval, widest at 1/3 of the total postpetiole length from anterior margin (DPpI 122-136) and 1.6 times wider than petiole (PPI 158-165).

Mandibular sculpture: distinctly longitudinally striate along entire length. Clypeus smooth and shiny, bearing 9 longitudinal rugae, with median ruga strongly developed and running posteriorly from the anterior clypeal margin to the level of antennal insertions before weakening. Cephalic dorsum predominantly longitudinally rugose, with transverse rugae incompletely connecting longitudinal rugae. In profile, sides of head coarsely rugo-reticulate; coarse punctures visible between rugae, particularly postero-ventrally to the compound eye. Sculpture of mesosoma in dorsal view with predominately longitudinal rugae on pronotum and mesonotum, becoming increasingly reticulate on the propodeum. Space between propodeal spines with several fine transverse rugae, propodeal declivity finely punctate. In profile, mesosoma rugo-reticulate; longitudinal rugae stronger on pronotum, becoming increasingly reticulate on mesopleuron, and giving way to coarse punctation on metapleuron. Petiole and postpetiole finely punctate, with weak overlying rugosity. Gaster smooth and shining except for small, widely spaced piligerous punctures.

Head, including mandibles and ventral regions nearly uniformly covered in a fine, whitish pubescence. Dorsal surface of the head, including clypeus, frons, posterior margin of the head and occipital corners equipped with long, blunt-tipped setae. Anterior clypeal margin with two pairs of long setae flanking the median carina. Antennal scape pilosity abundant, sharp-tipped and subdecumbent. Pronotal “neck”, pronotal humeri, propleurae and upper half of procoxae with short, fine whitish pubescence. Dorsal surfaces of mesosoma, waist segments and gaster with uniformly erect, long, abundant, blunt-tipped whitish setae, their bases spaced from each other by the length of the setae or less. Bases of the setae on the posterior margin of first gastral tergite separated by less than the length of the setae. Ventral surfaces of the post-petiole and gaster with sparse pilosity like that of the propleuron.

Queen.

Unknown

Male.

Unknown

Color.

Worker: Overall yellowish-orange with extremities, including antennae, legs, coxae, mouthparts and gaster (exluding first tergite) yellowish-white.

Distribution and ecology.

Temnothorax rufus is known only from the type locality, Kora National Park, which includes acacia bushland and riverine forests. The type specimens were collected via pitfall traps; presumably this is a ground-nesting species.

Taxonomic notes.

The only known specimens of Temnothorax rufus exhibit coloration unique among the species of the Afrotropical region, having light orange head, mesosoma and gaster and pale extremities.