Camponotus galoko Rakotonirina, Csosz & Fisher

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 : 117-119

Taxon classification Animalia Hymenoptera Formicidae

Camponotus galoko Rakotonirina, Csosz & Fisher sp. n. Figures 10B, 11B, 25, 40

Holotype worker.

Madagascar, Province Antsiranana, Forêt de Binara, 9.1 km 233° SW Daraina, -13.26333, 49.60333, 650-800 m, rainforest, ex rotten log, 5 Dec 2003 (B.L. Fisher et al.) collection code BLF09814, specimen code CASENT0178918 (CASC).

Paratypes.

8 workers same data as holotype but with the following specimen codes: CASENT0076246, CASENT0076247, CASENT0076248, CASENT0746972, CASENT0746973, CASENT0746974, CASENT0746975, CASENT0746976 (BMNH, MHNG, MSNG, CASC).

Additional material examined.

MADAGASCAR: Province Antsiranana: Forêt de Binara, 9.1 km 233° SW Daraina, -13.26333, 49.60333, 650-800 m, rainforest, (B.L. Fisher) (CASC), Galoko chain, Mont Galoko, -13.5888, 48.72864, 980 m, montane forest, (B.L. Fisher et al.) (CASC); Galoko chain, Mont Galoko, -13.59358, 48.73157, 1100 m, montane forest, (B.L. Fisher et al.) (CASC); Galoko chain, Mont Kalabenono, -13.64609, 48.67732, 937 m, rainforest, (B.L. Fisher et al.) (CASC).

Diagnosis.

In profile, anterior and posterior margins of petiolar node convex; in profile, propodeum strongly compressed anteroposteriorly, without clear distinction between dorsal margin and declivity; in dorsal view, mesonotum twice as broad as long; posterodorsal corner of mesonotum without extended shield.

Description.

Minor worker (Figs 10B, 11B, 25). In full-face view head slightly longer than broad (CWb/CL: 0.94-0.99), slightly diverging posteriorly; posterior margin broadly convex, lateral margins roughly straight. Eyes larger relative to size of head (EL/CS: 0.23-0.25), their posterior level located at about posterior fourth of head (PoOc/CL: 0.2-0.25). Anterior clypeal margin transverse; posterior margin medially notched. Mandible triangular, apical margin armed with six sharp teeth, which reduce in size towards basal angle of the mandible. Antennal scape short (SL/CS: 0.81-0.98), one fourth of the length surpassing posterior cephalic margin. Pronotum flat dorsally, anteriorly projecting into narrow ridge; dorsolateral portion longitudinally marginate. In dorsal view, mesonotum twice as broad as long, posterodorsal corner rounded, without extended lobe; lateral margin convex and strongly convergent posteriorly. Propodeum strongly compressed anteroposterioly, dorsal margin and declivity not distinctly separated; posterolateral portion extending laterally into sharp ridge. Propodeal spiracle on lower third of posterior face of propodeum. Maximum width of procoxa as large as the width of meso-metapleuron and propodeal surface together; femur of foreleg enlarged, twice as large as those of mid-leg and hind leg. Anterior and posterior margins of petiolar node convex. No constriction between abdominal segments III and IV.

Dorsum of head and mesosoma finely and densely reticulate punctate. Mandible finely and densely reticulate superimposed with scattered large punctures. Finer and denser reticulate punctures present on gastral tergites. Pronotum with a few pairs and mesonotum with one pair of whitish erect hairs; whitish hairs gathered at mid-height of posterior face of propodeum; whitish erect hairs present at mid-height of near lateral and on dorsal margins of posterior face of petiolar node; gastral segments with scattered and much shorter erect hairs; pubescence more abundant on gastral tergite than mesosomal dorsum. Integument shining black, antenna brown basally and darker apically; basal portion of mandible and leg dark brown, apical portion and trochanter light brown to yellowish-orange.

Major worker. Characteristics of minor worker, except: head in full-face view roughly as long as broad (CWb/CL: 0.96-1.03), lateral margins slightly convex and slightly converging near base of mandibles. Eyes smaller relative to head size (EL/CS: 0.19-0.22), their posterior level located roughly at posterior fourth of head (PoOc/CL: 0.27-0.31). Anterior margin of clypeus truncate and posterior. Antennal scape not extending beyond posterior cephalic margin. In dorsal view, metanotum visible between metanotal groove and propodeum. In lateral view, petiolar node more compressed anteroposteriorly. Lateral portion of head near base of mandible with sparse, large, piligerous punctures.

Distribution and biology.

This species is known only from the transitional humid forests of the Daraina and Galoko chain in the north of Madagascar (Fig. 40). The data indicate that individual workers forage on lower vegetation, while nests are mostly found in dead twigs above the ground and rarely in rotten logs.

Discussion.

Camponotus galoko is mostly similar to Camponotus echinoploides , but the posterodorsal corner of the mesonotum in the latter raises into a bluntly rounded shield. Camponotus galoko has a strongly anteroposteriorly flattened propodeum without a clear distinction between the propodeal dorsum and the declivity while the other species in the edmondi group have a propodeal dorsum and a declivitous surface separated by a blunt angle.

The taxonomic argument for Camponotus galoko is strengthened by the congruence between the results of traditional qualitative morphology and the NC-clustering technique. However, the classification success is only 90.91%, because its one minor worker is misclassified as Camponotus varatra by the confirmatory LDA with a low posterior probability of 0.76. This suggests that the entire range of minor worker forms of these species might not have been measured, and both species are closely related and have similar quantitative and qualitative morphology. Yet the two are distinguished by a morphological trait not easily incorporated into the morphometric approach. The dorsum of the head and mesosoma of Camponotus galoko are densely and finely reticulate whereas those of Camponotus varatra and Camponotus zavo are smooth, shining, and superimposed by imbrication.