Temnothorax cenatus (Bolton, 1982)

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 : 29-32

Taxon classification Animalia Hymenoptera Formicidae

Temnothorax cenatus (Bolton, 1982) Figs 4b and d; 6

Leptothorax cenatus : Bolton 1982: 327.

Temnothorax cenatus : Bolton 2003: 271.

Type material.

Holotype worker, KENYA, Lake Nakuru National Park, leaf litter, 6.XI.1974 (V. Mahnert) (MHNG) [examined]. Paratype, 1 worker from KENYA, Nakuru, Lake Elmenteita, 1800 m, 7.XI.1977 (V. Mahnert & J.-L. Perret) (BMNH: CASENT0900308) [examined].

Diagnosis.

The following character combination distinguishes Temnothorax cenatus from the other Afrotropical genus members:

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

Worker measurements

(n = 1). EL 0.174; FRS 0.222; HL 0.698; HW 0.558; IOD 0.468; IOcD N/A; MD 0.184; PH 0.219; PL 0.29; PPH 0.211; PPL 0.209; PPW 0.281; PTW 0.172; PW 0.398; SL 0.584; SPST 0.195; WL 0.922.

Indices: CI 79.9; DPeI 59.3; DPpI 134; LPeI 132; LPpI 99.1; OI 31.2; PeNI 43.2; PpNI 70.6; PPI 163; PSLI 27.9; SI 83.7.

Worker description.

Head longer than wide (CI 79.9); 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 relatively long, surpassing the posterior margin of the head by about the length of the first funicular segment (SI 105). Eyes moderate in size (OI 31.2), with 11 ommatidia in longest row.

Mesosoma relatively slender (WL 1.32 times HL); promesonotal suture not impressed, barely visible as a darkened line in dorsal view, but not indicated by a break in the sculpture. Metanotal groove shallowly impressed; visible as a broad, shallow concavity in lateral view. Propodeal spines acute and moderately long (PSLI 27.9); 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 132). In dorsal view petiole elongate (DPeI 59.3). Postpetiole in profile globular, nearly equal in height to petiolar node and relatively elongate (LPpI 99.1); in dorsal view transversely elongate-oval, widest at 1/3 of the total postpetiole length from anterior margin (DPpI 134) and 1.6 times wider than petiole (PPI 163).

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.

Mandibles, lateral and ventral regions of the head nearly uniformly covered in a fine, yellowish pubescence. Dorsal surface of the head, including clypeus, frons and posterior margin of the head 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 decumbent.

Pronotal “neck” and pronotal humeri with short, fine yellowish pubescence. Propleurae and upper half of procoxae with long, flexous, sharp-tipped pilosity. Dorsal surfaces of mesosoma, waist segments and gaster with uniformly erect, moderately long, abundant and blunt-tipped setae, their bases spaced from each other by the length of the setae or less. Ventral surfaces of the post-petiole and gaster with sparse pilosity like that of the propleuron.

Queen.

Unknown

Male.

Unknown

Color.

Worker: Overall light reddish brown, with head and gaster slightly darker.

Distribution and ecology.

So far, Temnothorax cenatus is only known from few localities in Central Kenya, all of which are savannah.

The holotype was collected from leaf litter, suggesting that this may be a ground nesting species.