Carebara silvestrii

Individuals and nest series have been collected from the leaf-litter and the soil with Winkler sifting, pitfall traps, and hand collections.

Identification
Fischer et al. (2014) - Antennae with eleven segments. Major worker: Head nearly rectangular or subquadrate but distincly longer than wide, with parallel to weakly convex sides, rounded posterolateral corners and transverse carina present near posterior head margin, lateral portions of mesosoma usually extensively areolate, dorsal face of head smooth and shiny in larger major workers and with sculpture in medium major workers except for medially smooth and shiny frontal area, propodeum with a pair of short, acute, subtriangular spines, gaster covered with abundant decumbent hairs. Minor worker: Head suboval in full-face view, sides strongly convex, posterolateral corners subangulate, and posterior margin with convex emargination, frons smooth and shiny, remainder of face with longitudinal rugulae and reticulations, propodeal spines slightly elongate triangular to short spinose, gaster with several decumbent and moderately long hairs.

Carebara silvestrii may be confused with Carebara perpusilla, but lateropronotum and anepisternum are smooth and shiny in major workers of C. perpusilla while in C. silvestrii they are areolate. The frons is often smooth and shiny in minor workers of C. silvestrii and the remainder of the face usually coarsely rugoreticulate, while the entire head is smooth and shiny in C. perpusilla.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Central African Republic, Equatorial Guinea, Gabon, Ghana, Guinea, Ivory Coast, Kenya , Senegal, Uganda, Zimbabwe.

Habitat
Occurs mainly in rainforest. Carebara silvestrii has been collected at elevations ranging from 10–2250 m.

Nomenclature

 *  silvestrii. Aneleus silvestrii Santschi, 1914d: 357, fig. 20 (s.w.) GHANA. Bernard, 1953b: 239 (m.). Combination in Oligomyrmex: Ettershank, 1966: 124; in Carebara: Fischer, Azorsa & Fisher, 2014: 71. Senior synonym of punctatus: Fischer, Azorsa & Fisher, 2014: 94.
 * punctatus. Aneleus (Aneleus) punctatus Karavaiev, 1931d: 43, fig. 2 (w.) KENYA. Combination in Oligomyrmex: Ettershank, 1966: 124; in Carebara: Fernández, 2004a: 235. Junior synonym of silvestrii: Fischer, Azorsa & Fisher, 2014: 94.

Worker
Fischer et al. (2014) - Major (n=6): HW 0.64–0.99 (0.85), HL 0.79–1.15 (1.02), SL 0.34–0.45 (0.41), MDL 0.38–0.57 (0.49), EL 0.04–0.07 (0.05), WL 0.58–0.87 (0.75), PNH 0.24–0.46 (0.37), PNW 0.32–0.48 (0.42), MNH 0.39–0.62 (0.53), PDH 0.24–0.38 (0.31), PTL 0.20–0.36 (0.28), PPL 0.15–0.21 (0.18), PTH 0.17–0.27 (0.22), PPH 0.14–0.23 (0.18), PTW 0.13–0.18 (0.15), PPW 0.15–0.23 (0.20), PSL 0.09–0.15 (0.12), MFL 0.37–0.60 (0.50), MTL 0.31–0.52 (0.43), CI 76–87 (83), SI 45–53 (49), MDI 56–61 (58), EI 6–7 (6), FI 57–65 (59), PSLI 13–16 (14), LPpI 92–107 (99), DPpI 100–128 (112), PpWI 122–144 (133), PpLI 56–81 (66), PpHI 76–88 (83).

Head longer than wide (CI 76–87), in full-face view nearly rectangular to subquadrate. Posterior margin of head weakly concave to V-shaped medially, posterolateral corners roundly convex, sides of the head nearly straight to slightly convex. Mandibles triangular and masticatory margin with five teeth including the basal tooth. Frontal carinae short or inconspicuous. Anterior margin of clypeus concave medially, sides angulate. Antennae with eleven segments, scapes short and not surpassing cephalic midlength (SI 45–53). Eyes small and consisting of one ommatidium (EI 6-7).

In profile, promesonotum roundly convex and higher than propodeum. Promesonotal suture present or absent on dorsum, metanotal groove present and impressed. Dorsal face of propodeum straight in profile, or slightly concave and declining posteriorly, anterodorsal corner weakly angulate, propodeal spines stout and subtriangular, posterior declivity concave. Propodeal spiracle rounded, situated slightly above center of lateral propodeum.

Petiole with relatively long peduncle, ventrally weakly concave anteriorly and slightly convex posteriorly, sometimes nearly straight over the whole length, subpetiolar process present as a small, angulate, forward-directed tooth, petiole node relatively high, anteroposteriorly somewhat compressed, dorsally subangulate anteriorly and posteriorly in smaller major workers, rounded in larger majors. Postpetiole in profile roundly convex dorsally, about as high as long (LPpI 92–107), and lower than petiole (PpHI 76–88). In dorsal view petiole node small, wider than long, anteriorly and posteriorly flattened and nearly straight to weakly convex, sides subangulate, postpetiole slightly wider than long (DpPI 100–128), about 1.3 times wider than petiole (PpWI 122–144), anteriorly and posteriorly weakly convex, laterally roundly convex.

Mandibles, clypeus and frons medially, and in large majors most of face, smooth and shiny with scattered punctures. In small majors sides of face with irregular longitudinal reticulations, grading to transverse reticulations towards posterior head margin, and with a transverse carina near posterior margin. In large majors, posterior head margin with transverse carina and with short transverse reticulations anterior and posterior of transverse carina. In all majors gena and frontal lobes with well-defined longitudinal striations. Dorsum of promesonotum centrally smooth and shiny, weakly reticulate near its margins, remainder of mesosoma areolate to weakly areolate, sometimes locally effaced on lateropronotum and katepisternum. Petiole node and postpetiole dorsally smooth and shiny, lateroventrally finely areolate. Gaster smooth and shiny with scattered punctures.

Head and body with moderately long suberect to subdecumbent hairs and short decumbent pilosity, scapes and tibiae with mostly decumbent pilosity. Color reddish brown, legs and antennae yellowish.

Minor (n=4): HW 0.36–0.44 (0.40), HL 0.41–0.51 (0.46), SL 0.29–0.34 (0.32), MDL 0.23–0.29 (0.26), EL 0.02, WL 0.45–0.59 (0.53), PNH 0.17–0.22 (0.19), PNW 0.23–0.27 (0.25), MNH 0.25–0.31 (0.28), PDH 0.17–0.22 (0.19), PTL 0.15–0.18 (0.16), PPL 0.11–0.12 (0.11), PTH 0.09–0.11 (0.10), PPH 0.08–0.09 (0.08), PTW 0.07–0.08 (0.08), PPW 0.08–0.10 (0.09), PSL 0.07–0.08 (0.07), MFL 0.30–0.39 (0.34), MTL 0.26–0.32 (0.29), CI 86–88 (87), SI 76–91 (81), MDI 62–66 (65), EI 4–6 (5), FI 80–91 (84), PSLI 17–19 (18), LPpI 139–160 (147), DPpI 69–81 (75), PpWI 109–122 (115), PpLI 67–80 (71), PpHI 71–83 (77).

Head longer than wide (CI 86–88), in full-face view anteriorly and posteriorly narrowed, sides strongly convex, posterior margin of head sharply concave, posterolateral corners angulate. Mandibles triangular with five teeth. Anterior margin of clypeus concave, bicarinate and divergent forward, sides angulate. Frontal carinae not surpassing midlength of head. Antennae eleven-segmented, scapes not reaching posterior head margin (SI 76–91). Eyes consisting of one ommatidium (EI 4-6).

In profile, promesonotum weakly convex, posterodorsal corner roundly convex, metanotal groove rounded and deeply impressed, pronotum anterodorsally transversely carinate. Dorsum of propodeum in profile straight, declining posteriorly, anterodorsal corner rounded, propodeal spines subtriangular and upwardly directed, posterior declivity of propodeum concave, lamella extending from the spines to the lobes. Propodeal spiracle rounded and situated below the base of spines and close to posterior border of lateral propodeum.

Petiole with relatively long peduncle, ventrally weakly concave anteriorly and slightly convex posteriorly, sometimes nearly straight over whole length, subpetiolar process present as small, angulate, forward-directed tooth, petiole node relatively low, small, subtriangular, or subangulate anteriorly and posteriorly. Postpetiole roundly convex in profile, on average about 1.5 times longer than high (LPpI 139–160), and lower than petiole (PpHI 71–83). In dorsal view petiole node small, almost wider than long, anteriorly weakly convex, posteriorly almost straight, sides subangulate, postpetiole longer than wide (DpPI 69–81), slightly wider than petiole (PpWI 109–122), anteriorly tapering, almost pedunculate, sides and posterior face roundly convex.

Mandibles, clypeus and frons smooth and shiny with scattered punctures, remainder of face irregularly rugreticulate. Dorsum of promesonotum weakly reticulate except for smooth and shiny center, and central area of lateral pronotum with effaced sculpture. Remainder of lateropronotum, mesopleuron and propodeum areolate, except smooth and shiny posterior declivity. Gaster and dorsum of petiole node and postpetiole smooth and shiny, remainder weakly areolate to areolate-rugose.

Head and body with moderalely long suberect to subdecumbent hairs and short decumbent pilosity. Scapes and tibiae with decumbent pilosity. Color reddish brown, legs and antennae yellowish.

References based on Global Ant Biodiversity Informatics

 * Bernard F. 1953. La réserve naturelle intégrale du Mt Nimba. XI. Hyménoptères Formicidae. Mémoires de l'Institut Français d'Afrique Noire 19: 165-270.
 * Diame L., B. Taylor, R. Blatrix, J. F. Vayssieres, J. Y. Rey, I. Grechi, and K. Diarra. 2017. A preliminary checklist of the ant (Hymenoptera, Formicidae) fauna of Senegal. Journal of Insect Biodiversity 5(15): 1-16.
 * Fischer G., F. Azorsa, F. Fernandez, and B. L. Fisher. 2014. The ant genus Carebara Westwood (Hymenoptera, Formicidae): synonymisation of Pheidologeton Mayr under Carebara, establishment and revision of the C. polita species group. Zookeys doi: 10.3897/zookeys.@@.7922
 * IZIKO South Africa Museum Collection
 * Karavaiev V. 1931. Ameisen aus Englisch-Ostafrika. Zool. Anz. 95: 42-51.
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 * Medler J. T. 1980: Insects of Nigeria - Check list and bibliography. Mem. Amer. Ent. Inst. 30: i-vii, 1-919.
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 * Santschi F. 1914. Formicides de l'Afrique occidentale et australe du voyage de Mr. le Professeur F. Silvestri. Bollettino del Laboratorio di Zoologia Generale e Agraria della Reale Scuola Superiore d'Agricoltura. Portici 8: 309-385.
 * Taylor B. 1980. Ants of the Nigerian Forest Zone (Hymenoptera: Formicidae). IV. Myrmicinae (Myrmecinini to Tetramoriini). Cocoa Research Institute of Nigeria Research Bulletin 7: 1-63.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004
 * Yeo K., S. Konate, S. Tiho, and S. K. Camara. 2011. Impacts of land use types on ant communities in a tropical forest margin (Oumé - Cote d'Ivoire). African Journal of Agricultural Research 6(2): 260-274.
 * Yeo K., T. Delsinne, S. Komate, L. L. Alonso, D. Aidara, and C. Peeters. 2016. Diversity and distribution of ant assemblages above and below ground in a West African forest–savannah mosaic (Lamto, Cote d’Ivoire). Insectes Sociaux DOI 10.1007/s00040-016-0527-6