Camponotus ethicus Forel

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 : 114-117

Taxon classification Animalia Hymenoptera Formicidae

Camponotus ethicus Forel Figures 6A, 7A, 24, 39

Camponotus ethicus Forel, 1897: 200. Lectotype minor worker, present designation, Madagascar, Antsiranana Province, Sakatia bay, Nosy Be (Voeltzkow), AntWeb CASENT0101389 (MHNG) [examined]. Paralectotypes: 2 workers and 2 males, of same data as lectotype, but worker and male respectively specimen coded as: CASENT0101388 and CASENT0101387 (MHNG); CASENT0101176 and CASENT0101177 (NHMB) [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].

Additional material examined.

MADAGASCAR: Province Antsiranana: Galoko chain, Mont Kalabenono, -13.64609, 48.67732, 937 m; -13.64179, 48.67282, 643 m; -13.63999, 48.67374, 498 m, rainforest, (B.L. Fisher et al.) (CASC); Réserve Spéciale d’Ambre, 3.5 km 235° SW Sakaramy, -12.46889, 49.24217, 325 m, tropical dry forest, (Fisher, Griswold et al.) (CASC); Province Mahajanga: Forêt d’Anabohazo, 21.6 km 247° WSW Maromandia, -14.30889, 47.91433, 120 m, tropical dry forest, (Fisher, Griswold et al.) (CASC).

Diagnosis.

Larger species (CS: 1.92-2.58; ML: 3.49-4.18) with uniformly black to dark brown body color; in profile anterior margin of petiolar node convex and posterior margin straight; level of the propodeal dorsum abruptly lower than level of the promesonotal dorsum; pronotal dorsum without numerous erect hairs; humeral angle extended anteriorly into a narrow ridge.

Description.

Minor worker (Figs 6A, 7A, 24). In full-face view head subquadrate (CWb/CL: 0.87-0.89), slightly diverging posteriorly; posterior margin more or less straight. Eyes not breaking lateral outline of head, their posterior level located at posterior fifth portion of head (PoOc/CL: 0.21-0.25). Anterior clypeal margin straight; posterior margin weakly notched medially. Mandible triangular, apical margin armed with six sharp teeth. Antennal scape long, apical half surpassing posterior cephalic margin. Pronotal dorsum flat, anterodorsal corner projecting anteriorly into narrow ridge; anterior margination present; pronotal dorsum and lateral portion anteriorly separated by sharp margination. In dorsal view, mesonotum as long as broad; in profile, mesonotal dorsum inclined posteriorly and propodeal dorsum nearly horizontal and distinctly situated at lower level than promesonotum; mesopleuron and propodeal surface together distinctly longer than lateral portion of pronotum; propodeal dorsum almost horizontal and declivitous surface nearly vertical; propodeal spiracle located anterior to posterolateral margin of propodeum. Width of procoxa larger than width of mesopleuron. In profile anterior margin of petiolar node convex and posterior margin more or less straight. Constriction between abdominal segments III and IV lacking.

Dorsum of head and mesosoma with fine and dense imbrication. Imbricate sculpture much finer and denser on gastral tergites. Mandible imbricate and superimposed with sparse large punctures. Erect hairs lacking on pronotum; one pair present on mesonotum, propodeum near junction of dorsum and declivity, and upper level of lateral margin of petiole. Few pairs of erect hairs on head dorsum from clypeus and edge of frontal lobe to posterior portion of head; several scattered pairs organized transversely on anterior and posterior portions of each gastral tergite; pubescence short and reduced in number. Body coloration black; appendages dark reddish black.

Major worker. With characteristics of minor worker, except: head much more square (CL/CWb: 1.008-1.08); lateral margins slightly convex. Eyes located more anteriorly, their posterior level on posterior fourth of head (PoOc/CL: 0.227-0.252). One third of apical portion of scape extending beyond posterior cephalic margin. Scattered piligerous punctures present laterally on head from the level of anterior margin of eyes to near base of mandible.

Distribution and biology.

Known from the dry forests of the Parc National Sahamalaza and the Reserve Spéciale Ambre, and the transitional rainforest of the Galoko Chain in the northwestern part of Madagascar (Fig. 39), Camponotus ethicus is arboreal, forages most often on lower vegetation, and nests in dead branches above the ground.

Discussion.

The lower level of the propodeal dorsum relative to the promesonotum and the larger body size combined with the dark color of the legs make Camponotus ethicus easy to separate from Camponotus robustus and the rest of the species in the edmondi group. The delimitation of Camponotus ethicus based on qualitative morphology-based taxonomy is congruent with the classification hypothesis provided by the NC-clustering algorithm, strengthening its status as a species.