Carebara vazimba Azorsa & Fisher

Azorsa, Frank & Fisher, Brian L., 2018, Taxonomy of the ant genus Carebara Westwood (Formicidae, Myrmicinae) in the Malagasy Region, ZooKeys 767, pp. 1-149 : 1

Carebara vazimba Azorsa & Fisher sp. n.

Holotype.

(major worker), MADAGASCAR, Antsiranana , Ambondrobe, 41.1 km 175° Vohemar, -13.71533, 50.10167, 10 m, littoral rainforest, 29.xi.2004, (B.L. Fisher). Collection code BLF11100, (CASC: CASENT0055532). Paratypes: (13 major workers and 17 workers), with same data as holotype, 10 major workers (BMNH: CASENT0055521, CASC: CASENT0055650, CASENT0055647, CASENT0055641, CASENT0055652, CASENT0055525, CASENT0055527, MCZ: CASENT0055536, MHNG: CASENT0055531, NHMB: CASENT0055643), and 15 workers (BMNH: CASENT0055524, CASC: CASENT0055636, CASENT0055535, CASENT0055640, CASENT0055518, CASENT0055526, CASENT0055529, CASENT0055528, CASENT0055644, CASENT0055538, CASENT0055530, CASENT0055651, MCZ: CASENT0055519, MHNG: CASENT0055523, NHMB: CASENT0055638). 2 major workers and 2 workers with same data as holotype but collected by 30.xi.2004: BLF11107, 1 major worker and 1 worker (CASC: CASENT0110667), BLF11123, 1 major worker and 1 worker (CASC: CASENT0052827).

Diagnosis.

Antennae ten-segmented. Major: Head nearly subrectangular, longer than wide, lateral margins straight and parallel, posterolateral corners well developed, posterior margin of head deeply concave in the middle, head with longitudinal rugae directed to the posterior margin; dorsum of propodeum flat, and declining posteriorly, posterodorsal corner with a pair of small triangular teeth; gaster with short decumbent hairs, and dispersed and longer subdecumbent hairs. Minor: Head nearly subrectangular, slightly longer than wide, posterior margin of head nearly straight, weakly concave, lateral margins convex; dorsum of propodeum nearly flat, posterodorsal corner with a pair of small triangular teeth, combined outline of dorsal surface of peduncle and anterior face of node concave, and posterior face slightly convex; gaster with short decumbent hairs, and longer and dispersed subdecumbent hairs.

Description of major workers.

Measurements (n=6): HL 0.64-1.02 (1.01); HW 0.50-0.78 (0.75); SL 0.26-0.35 (0.34); ML 0.14-0.24 (0.24); EL 0.01-0.05 (0.05); EM 0.16-0.26 (0.25); HD 0.34-0.57 (0.56); WL 0.52-0.86 (0.81); PSL 0.05-0.10 (0.10); PW 0.31-0.54 (0.52); MFL 0.30-0.47 (0.46); MFW 0.07-0.11 (0.10); MTL 0.23-0.38 (0.36); PTL 0.18-0.36 (0.36); PNL 0.09-0.14 (0.14); PTH 0.15-0.25 (0.24); PTW 0.14-0.23 (0.23); PPL 0.12-0.20 (0.19); PPNL 0.10-0.18 (0.18); PPH 0.12-0.24 (0.22); PPW 0.17-0.28 (0.27); GL 0.41-0.97 (0.92); GW 0.40-0.86 (0.86); CI 74-78 (74); MI 22-25 (24); SI 34-42 (34); MLI 58-64 (61); PPLI 53-67 (53); PPI 117-129 (117); PSI 9-13 (13).

Head longer than wide (CI 74-78), in full-face view nearly subrectangular, about 1.3 times longer than wide, slightly narrowed posteriorly. Posterior margin of head deeply concave in the middle, posterolateral corners well developed and rounded, lateral margins straight and parallel. Mandibles with six teeth. Anterior margin of clypeus nearly straight, and laterally convex. Antennae with ten segments. Scapes short (HL 0.64-1.02, SL 0.26-0.35, SI 34-42). Ocelli present or absent. Eyes present, consisting of one to twenty ommatidia (EL 0.01-0.05). Supraclypeal area triangular and well defined.

In profile view, posterolateral corner of head with an angulate and triangular tooth resembling a horn. Promesonotum high and nearly rounded. Promesonotal suture present or absent on dorsum, mesonotum absent or present, metanotal groove deeply impressed. Propodeum lower than promesonotum, about 1.5 times higher than long, dorsal face of propodeum flat and declining posteriorly, anterodorsal corner rounded, posterodorsal corners each armed with a triangular tooth, declivity concave with thin lateral laminae. Propodeal lobes convex. Propodeal spiracle rounded and situated slightly above mid-height of sclerite, and beyond mid-length of sclerite by about half the diameter of the spiracle, distance from propodeal spiracle to posterodorsal corner of propodeum about twice the diameter of the spiracle (PSL 0.05-0.10), and distance to declivity about 1.3 times the diameter of the spiracle. In dorsal view, promesonotum about as long as wide, anterior margin and sides rounded, narrowed posteriorly; sides of propodeum straight.

Petiole longer than high (PTL 0.18-0.36, PTH 0.15-0.25) and with relatively long peduncle, ventral face slightly convex in the middle. Combined outline of dorsal surface of peduncle and anterior face of node concave at center, posterior face of node vertical and straight, anterodorsal corner convex, posterodorsal corner rounded, and dorsum nearly rounded. Subpetiolar process produced as a small denticle, almost same as the diameter of the propodeal spiracle. Postpetiolar node convex and lower than petiolar node. In dorsal view, petiolar node almost as wide as postpetiolar node (PTW 0.14-0.23, PPW 0.17-0.28) and petiolar node wider than long (PNL 0.09-0.14, PTW 0.14-0.23), anterior and posterior margins of petiole and postpetiole almost straight, sides of petiole and postpetiole rounded.

Dorsal surface of mandibles, clypeus and frons smooth and shiny with scattered piligerous punctae on head and mandibles. Head with longitudinal and parallel rugae directed to posterior margin of head. Mesosoma smooth and shiny, except for katepisternum and propodeum (areolate), metapleuron (finely areolate and with longitudinal rugae), and sides of pronotum (finely longitudinal rugulose). Petiole, ventral face and sides of postpetiole areolate. In dorsal view, median area of promesonotum smooth and shiny, as well as postpetiole and gaster. Propodeum and petiole weakly sculptured in smaller major workers and smooth and shiny in larger major workers.

Lateral margins of the head with short appressed hairs and long erect to suberect hairs, posterior margin with subdecumbent hairs. Scapes with appressed hairs. Outer margin of mandibles with sparse and short appressed hairs. Mesosoma with short and long erect and suberect hairs. Petiole and postpetiole with short decumbent hairs and long subdecumbent hairs. Tibia with appressed hairs. Gaster with short decumbent hairs and long suberect to subdecumbent hairs. Color yellowish ferruginous.

Description of minor workers.

Measurements (n=10): HL 0.33-0.39; HW 0.29-0.34; SL 0.20-0.24; ML 0.08-0.09; EL 0.01-0.02; EM 0.09-0.11; HD 0.19-0.23; WL 0.32-0.39; PSL 0.02-0.04; PW 0.18-0.21; MFL 0.20-0.25; MFW 0.05-0.06; MTL 0.14-0.18; PTL 0.12-0.14; PNL 0.06-0.07; PTH 0.09-0.11; PTW 0.07-0.09; PPL 0.07-0.10; PPNL 0.06-0.08; PPH 0.06-0.08; PPW 0.10-0.12; GL 0.27-0.39; GW 0.21-0.26; CI 86-89; MI 22-27; SI 59-62; MLI 68-74; PPLI 54-71; PPI 122-147; PSI 6-13.

Head longer than wide (CI 86-89), in full-face view nearly subrectangular, about 1.2 times longer than wide. Posterior margin of head nearly straight, weakly concave, posterolateral corners rounded, lateral margins convex. Mandibles with five teeth. Anterior margin of clypeus nearly straight, and laterally convex. Antennae with ten segments. Scape fails to reach posterior margin of head (HL 0.33-0.39, SL 0.20-0.24, SI 59-62). Eyes present, consisting of one ommatidium (EL 0.01-0.02). Supraclypeal area short and triangular.

In profile view, promesonotum weakly convex, nearly flat, metanotal groove present. Propodeum about 1.3 times higher than long, dorsal face of propodeum nearly flat and declining posteriorly, anterodorsal corner rounded, posterodorsal corners each armed with a small triangular tooth, declivity concave with thin lateral laminae. Propodeal lobes convex. Propodeal spiracle small, rounded, and situated above mid-height of sclerite, and beyond mid-length of sclerite by about half the diameter of the spiracle, distance from propodeal spiracle to posterodorsal corner of propodeum about 2.2 times the diameter of the spiracle (PSL 0.02-0.04), and distance to declivity same as the diameter of the spiracle. In dorsal view, promesonotum about 1.1 times longer than wide, anterior margin rounded, sides convex and narrowed posteriorly; sides of propodeum straight.

Petiole longer than high (PTL 0.12-0.14, PTH 0.09-0.11) and with relatively short peduncle, ventral face convex at center. Combined outline of dorsal surface of peduncle and anterior face of node concave, posterior face of node vertical and slightly convex, anterodorsal and posterodorsal corner convex, dorsum rounded. Subpetiolar process produced as a small denticle, almost as large as the diameter of the propodeal spiracle. Postpetiolar node convex and lower than petiolar node. In dorsal view, postpetiolar node wider than petiolar node (PTW 0.07-09, PPW 0.10-0.12), and petiolar node wider than long (PNL 0.06-0.07, PTW 0.07-0.09), anterior and posterior margins of petiole and postpetiole nearly straight, sides nearly rounded in petiole and postpetiole.

Dorsal surface of head, mandibles and clypeus smooth and shiny with scattered piligerous punctae on head and mandibles. Gena and frontal lobes with longitudinal rugae. Mesosoma smooth and shiny, except for katepisternum and propodeum (areolate), and metapleuron (longitudinally areolate-rugose). Petiole and ventral face of postpetiole areolate-rugose. In dorsal view, promesonotum, postpetiole and gaster smooth and shiny; propodeum and petiole areolate.

Lateral margins and posterior margin of head with short decumbent hairs. Scapes with appressed hairs. Outer margin of mandible with sparse appressed hairs. Mesosoma with short and long suberect hairs. Petiole and postpetiole with short appressed hairs and long subdecumbent hairs. Tibia with appressed hairs. Gaster with short decumbent to appressed hairs and long subdecumbent hairs. Color yellowish ferruginous.

Distribution and biology.

Carebara vazimba is known from the north of Madagascar (Figure 69). This species was found in littoral rainforest and rainforest at 10 m and 240 m, respectively. Individuals of C. vazimba were found in rotten logs, leaf mold, and rotten wood. Specimens were collected using maxi-Winkler traps.

Comments.

Carebara vazimba can be confused with C. kabosy but can be separated by the length of the propodeal tooth, which is shorter than propodeal spiracle diameter in C. vazimba and slightly longer in C. kabosy . C. vazimba is distributed in the north of Madagascar, while C. kabosy is distributed in the north, northeastern and nortwestern areas of Madagascar. Other five species were collected at the same localities: C. bara , C. berivelo , C. grandidieri , C. jajoby , and C. kabosy .

C. vazimba have three intermediates in the major worker subcaste (Figure 67). The posterolateral corner of head in intermediate 1 is slightly narrowed posteriorly, the posterior margin of the head is medially concave in all intermediates. Eyes are small and reduced to one ommatidium in intermediate 1 but intermediate 3 has eyes made up of one to twelve ommatidia. Ocelli are absent in intermediates 1 and 2, but present in intermediate 3 (one ocellus). Reduced flight sclerites are present in intermediate 3, and absent in intermediates 1 and 2. The promesonotum is nearly rounded in intermediates 1 and 2, and strongly convex in intermediate 3. The dorsum of the mesosoma is convex anteriorly and gradually slopes to the declivity in intermediate 3, while in intermediates 1 and 2 the dorsum of the mesosoma is convex anteriorly, propodeum below the promesonotum. There is no variation in the form of the petiole. The sculpture of the head of intermediate 3 is more striking than that of intermediates 1 and 2, where rugae on the head are more finely marked and the frontal area is smooth and shiny. Pilosity on the head and body follows the same pattern in all intermediates.

Additional material examined.

MADAGASCAR: Antsiranana : Antsiranana , Ambondrobe, 41.1 km 175° Vohemar, -13.71533, 50.10167, 10 m, littoral rainforest, 29.xi.2004, (B.L. Fisher); Antsiranana , Forêt Ambanitaza, 26.1 km 347° Antalaha, -14.67933, 50.18367, 240 m, rainforest, 26.xi.2004, (B.L. Fisher); Antsiranana : Forêt d’ Andavakoera, 21.4km 75° ENE Ambilobe; 4.6 km 356° N Betsiaka, -13.11833, 49.23, 425 m, rainforest, 15.xii.2003, (B.L. Fisher); Antsiranana , Forêt Ambato, 26.6 km 33° Ambanja, -13.4645, 48.55167, 150 m, rainforest, 8.xii.2004, (B.L. Fisher).