Camponotus robustus Roger

Rakotonirina, Jean Claude, Csosz, Sandor & Fisher, Brian L., 2016, Revision of the Malagasy Camponotusedmondi species group (Hymenoptera, Formicidae, Formicinae): integrating qualitative morphology and multivariate morphometric analysis, ZooKeys 572, pp. 81-154 : 128-129

Taxon classification Animalia Hymenoptera Formicidae

Camponotus robustus Roger Figures 7B, 29, 44

Camponotus robustus Roger, 1863: 135. Lectotype minor worker, present designation, Madagascar (Humblot), AntWeb CASENT0101390 (MHNG) [examined]. Paralectotypes of 5 workers: 2 in the same pin as lectotype; 2 workers with the same data but specimen coded as CASENT0104621 and CASENT0104622 (ZMHB) [examined]. Combination in Camponotus (Myrmentoma) : Forel 1912: 92; in Camponotus (Orthonotomyrmex) : Forel 1914: 273; Emery 1920: 258; Wheeler 1922: 1049; in Camponotus (Myrmisolepis) : Santschi 1921: 310; in Camponotus (Myrmepinotus) : Emery 1925: 127; Bolton 1995: 120, 131].

Additional material examined.

MADAGASCAR: Province Antsiranana: Forêt Ambanitaza, 26.1 km 347° Antalaha, -14.67933, 50.18367, 240 m, rainforest, (B.L. Fisher) (CASC); Forêt de Binara, 9.1 km 233° SW Daraina, -13.26333, 49.60333, 800 m, rainforest (B.L. Fisher et al.) (CASC); Makirovana forest, -14.10295, 50.01984, 90 m, rainforest (B.L. Fisher et al.) (CASC); Province Fianarantsoa: Réserve Forestière d’Agnalazaha, Mahabo, 42.9 km 215° Farafangana, -23.19383, 47.723, 20 m, littoral rainforest, (B.L. Fisher et al.) (CASC); Réserve Spéciale Manombo 24.5 km 228° Farafangana, -23.01583, 47.719, 30 m, rainforest, (B.L. Fisher et al.) (CASC); Province Toamasina: Ile Sainte Marie, Forêt Ambohidena, 22.8 km 44° Ambodifotatra, -16.82433, 49.96417, 20 m, littoral rainforest, (B.L. Fisher et al.) (CASC); Parc National Mananara-Nord, 7.1 km 261° Antanambe, -16.455, 49.7875, 225 m, rainforest, (B.L. Fisher et al.) (CASC); Station Forestière Tampolo, 10 km NNE Fenoarivo Atsinanana, -17.2825, 49.43, 10 m, littoral rainforest, (B.L. Fisher) (CASC); Sahafina Forest 11.4 km W Brickaville, -18.81445, 48.96205, 140 m, rainforest, (B.L. Fisher et al.) (CASC); Mahavelona (Foulpointe), -17.66667, 49.5, in sandy forest (A. Pauly) (CASC); Forêt d’Analava Mandrisy, 5.9 km 195 º Antanambe, -16.48567, 49.847, 10 m, littoral rainforest, (B.L. Fisher et al.) (CASC); Réserve Ambodiriana, 4.8 km 306° Manompana, along Manompana River, -16.67233, 49.70117, 125 m, rainforest, (B.L. Fisher et al.) (CASC); Parc National Masoala, 39.7 km 151° SSE Maroantsetra, -15.71333, 49.97167, 150 m, rainforest, (B.L. Fisher, H.J. Ratsirarson) (CASC); 11km SE Ampasimanolotra (= Brickaville), -18.9, 49.13333, 5 m, littoral rainforest (P.S. Ward) (PSWC).

Diagnosis.

Larger species (CS: 1.882-3.725; ML: 3.098-4.666) with uniformly black to dark brown body color; in profile anterior margin of petiolar node convex and posterior margin straight; level of propodeal dorsum not abruptly lower than level of promesonotal dorsum; pronotum covered with numerous erect hairs and pubescence.

Description.

Minor worker (Figs 7B, 29). In full-face view head rectangular and longer than broad (CWb/CL: 0.91-0.98); lateral margins nearly straight and slightly diverging posteriorly; posterior margin broadly convex. Eyes not breaking lateral outline of head, posterior level located at posterior fourth portion of head (PoOc/CL: 0.21-0.27). Anterior clypeal margin broadly triangular. Mandible triangular, apical margin armed with six teeth. More than apical third portion of antennal scape surpassing posterior cephalic margin. Anterodorsal corner of pronotum projecting anteriorly into narrow ridge; anterior margination strong near corner and weak towards the center; pronotal dorsum rounding to lateral portion. In dorsal view, mesonotum broader than long. In lateral view, mesonotal dorsum slightly inclined posteriorly as is the propodeal dorsum, which joins the declivity at a blunt angle; mesopleuron and propodeal surface together distinctly longer than lateral portion of pronotum; propodeal spiracle located on lateral portion of propodeum anterior to posterolateral margin. Maximum width of procoxa larger than width of meso-metapleuron. In profile anterior margin of petiolar node convex and posterior margin more or less straight. Constriction between abdominal segments III and IV absent.

Dorsum of head, mesosoma, and gaster finely and densely reticulate rugose. Lateral portion of head finely and densely reticulate punctate. Mandible imbricate superimposed with punctures. Whitish yellow erect hairs numerous on head, mesosoma, and gaster. Petiole with erect hairs from lateral margins to posterodorsal angle. Pubescence abundant. Head, mesosoma, antennal scape, and distal portion of flagellum, femur, tibia, and basitarsus black; trochanter and metatarsi as well as basal portion of flagellum brown.

Major worker. With characteristics of minor worker, except: head broader than long (CWb/CL: 0.98-1.02); sides slightly convex and strongly converging towards base of mandibles. Eyes located more anteriorly, their posterior level on posterior third of head (PoOc/CL: 0.26-0.3). Antennal scape barely extending beyond posterior cephalic margin. Anteromedian portion of pronotum without margination. Lateral portion of head smooth and shining with scattered small punctures from which short hairs arise. Mandible with longitudinal striation near apical margin apart from fine imbrication and piligerous punctures.

Distribution and biology.

Camponotus robustus occurs in the rainforests of eastern Madagascar, from Binara in the north to Ivohibe Forest in the south (Fig. 44). The species is both terrestrial and arboreal. Its workers forage individually on the forest floor, on lower vegetation, and in the canopy and nest in rotten logs, rotting tree stumps, or in dead branches above the ground.

Discussion.

Camponotus robustus is similar to Camponotus ethicus , but the latter has no erect hairs on the dorsum of the mesosoma and has a propodeal dorsum lower than the promesonotum. The remainder of the edmondi group can be distinguished from this species by their smaller size and yellow to brown legs.

Species delimitation of Camponotus robustus based on traditional qualitative taxonomy is congruent with the grouping generated by the morphometric dendrogram and the species was classified correctly at 100% by the confirmatory LDA.