Camponotus karaha

Specimens have been collected on the ground in rotten logs and on low vegetation.

Identification
Rasoamanana et al. (2007) - Workers of Camponotus karaha can be differentiated from the other three species of Madagascar Myrmopytia by the triangular form of the petiole in lateral view, and the protruding clypeus.

Workers of C. karaha exhibit morphological variability in qualitative traits such as sculpture, color of mesosoma, and profile of propodeum that differ between populations.

Populations from the north of its distribution range differ notably in shape of propodeal dorsum and petiolar node and further research on additional samples are needed to further evaluate species status of these populations. For now, we note the differences of the northern populations from the more typical karaha.

Variant 1. This variant is the typical C. karaha, and is fairly widespread throughout the eastern rainforest of Madagascar. It can be recognized by having a propodeum dorsum smoothly convex in lateral view, declivitous face of petiole distinctly flat with defined lateral margins, petiolar apex forms a right angle.

Variant 2. Workers are known from montane rainforest of Montagne d’Anjanaharibe and Parc National Masoala, Ambanizana, elevation 800–1100 m. It can be differentiated from the other morph by the propodeal dorsum almost flat in lateral view, declivitous face of petiole convex and not marginate laterally, petiolar apex acuminate.

Distribution
Known from localities along the eastern rainforest and montane rainforest of Madagascar at elevations ranging from 175 to 1325 m.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Mimicry
Within Madagascar, there are four species of Camponotus, Camponotus imitator, Camponotus jodina, Camponotus karaha and Camponotus longicollis, that mimic the general form and behavior of the Aphaenogaster swammerdami group, specifically Aphaenogaster bressleri, Aphaenogaster gonacantha, Aphaenogaster makay, Aphaenogaster sahafina and Aphaenogaster swammerdami. These Camponotus mimics are often seen foraging with workers of Aphaenogaster, but potential benefits for Camponotus have not been studied (Csosz et al., 2021).

Nomenclature

 * . Camponotus karaha Rasoamanana, et al. 2017: 141, figs. 4B, 5B, 6B, 7B, 8A, 13-15, 18 (s.w.) MADAGASCAR.

Worker
Minor Head longer than wide, anterior region of head elongated, caudate, sides of the head narrowed in front of eyes, CS 1.723 mm [1.35, 1.92] (n=47). Erect filiform setae on lateral margin of head and on gena. Eyes located anterior to the midlength of sides of head in full-face view, PoOC/CL 0.431 [0.404, 0.473]. Frontal carinae convex, FR/CS 0.238 [0.213, 0.267]. Scape distinctly surpassing posterior margin by almost half of its length, SL/CS 1.832 [1.651, 2.051]. Anterior margin of clypeus produced into an obtuse angle; in lateral view, clypeus protruding strongly, anterior portion may appear indented, masticatory margin with 6 teeth, palps long with respect to head size.

Pronotum weakly undulant. Mesonotum straight and elongate, distinctly compressed laterally anterior to mesothoracic spiracles, MPD/CS 1.401 [1.196, 1.595]. Erect setae absent, appressed pubescence sparsely distributed. Mesothoracic spiracles prominent; propodeal dorsum protuberant, noticeably convex. ML/CS 2.203 [1.989, 2.405].

Petiole conical, petiolar apex with an obtuse angle, posterior face of petiole flat to slightly convex, sides always distinct. PEW/CS 0.198 [0.169, 0.244].

Entire body generally black, pronotum may vary to brown, coxae a lighter color than mesosoma, basitarsus and up to 5 basal funiculi whitish. Mesonotum and propodeum smooth and glabrous to microsculptured with sparse appressed to subdecumbent setae.

Major Head subrectangular in full face view, occipital portion broad, sides of the head mostly parallel and weakly convex, CS 2.108 mm [1.92, 2.28] (n=9). Erect filiform setae present on entire head capsule. Eyes located at midlength of head capsule in full-face view. PrOc/CL 0.434 [0.417, 0.455]. Frontal carinae straight posterior to antennal insertion and curving smoothly toward the posterior margin of clypeus. FR/CS0.270 [0.255, 0.292]. Scape surpassing posterior margin by one fourth of its length. SL/ CS 0.971 [0.711, 1.331]. Anterior margin of clypeus projecting to an obtuse angle and, in lateral view, posterior portion of clypeus weakly produced dorsally masticatory margin of mandible with 6 teeth, palps long with respect to head size.

Pronotum weakly undulant. Anterior region of mesonotum (immediately posterior to the pro-mesonotal suture) in profile rising above pronotum. Dorsal outline of mesonotum and propodeum form a continuous straight line interrupted by a shallow metanotal groove. Erect setae present, appressed pubescence sparsely distributed. Mesothoracic spiracle feebly produced laterally. ML/CS 1.872 [1.800, 2.009].

In profile, petiole conical, node summit acute. PEW/CS 0.222 [0.211, 0.250].

Entire body black; femora and tibia dark brown, basitarsus of second and third legs light brown, funicular segments light brown, becoming dark apically. Pronotum and mesonotum microreticulate, sides of propodeum finely punctate, standing filiform setae present in all surfaces.

Type Material
Holotype worker: Madagascar, Province Antsiranana, Parc National de Marojejy, Manantenina River, 27.6 km 35° NE Andapa, 9.6 km 327° NNW Manantenina, -14.435 49.76, 16.xi.2003, 775 m, rainforest, ex rotten log. (B.L. Fisher et al.). Collection code: BLF08983 Unique specimen identifier: CASENT0487715.

Paratype workers: Six workers with the same data as holotype, Collection code: BLF08983, Unique specimen identifiers: CASENT0487711 (2w), CASENT0487712 (2w), CASENT0487713 (2w), (CASC).

Etymology
The Malagasy word “karaha” means similar, look-alike.