Camponotus marianensis

Identification
Dark, thick-headed Camponotus species are not uncommon, and this species does closely resemble Camponotus sachalinensis (Forel 1904), which is found in Japan. However, not only is that species overall black, including the appendages, but it also lives in mountainous regions of northern Japan, making it an unlikely candidate to colonize the Marianas. Also from Japan, Camponotus japonicus Mayr 1866 appears very similar, but its propodeal declivity is not as steep and it, like C. sachalinensis, is monochrome black. Camponotus marianensis does resemble some identified specimens from Indonesia, but it can be primarily distinguished by its coloration and secondarily by its squarish head shape, small eyes, wide mesosoma, and propodeal profile. (Clouse 2007)

Distribution based on Regional Taxon Lists
Indo-Australian Region: Marshall Islands, Micronesia (Federated States of), Northern Mariana Islands.

Nomenclature

 *  marianensis. Camponotus marianensis Clouse, 2007a: 7, pl. 2D-F, 3A (w.) MICRONESIA (Yap I.). [Also described as new by Clouse, 2007b: 201, 214.]

Worker
HOLOTYPE: TL 2.75, HL 1.32, HW 1.22, CI 92, SL 0.92, SI 75, PW 0.85, ML 0.35. Mandible outer margin strongly curving to a sharp apical tooth that points parallel to anterior clypeal margin. Anterior clypeus extending past mandibular insertions and very slightly convex across. Median clypeus curved slightly away from vertex, antennal insertions separated from clypeus by distance almost equal to the distance from nearest clypeal margin to clypeal midpoint. Head nearly square in front view. In frontal view, bottom margin of eyes located at halfway point of the head, their inner margins more than halfway from frontal lobes to sides of the head, their outer margins separated from sides of head by less than scape width. Antennae 12-segmented, last segment almost as long as preceding two. Scape extending beyond vertex by distance equal to first segment of the funiculus. Mesosoma in profile sloping gently from anterior pronotum to dorsal propodeum, then dropping severely, making concave posterior surface. Petiole three times taller than long, anterior and posterior faces mostly parallel although node slightly bulging dorsally. Color: Body generally mahogany to black. Gaster with grey stripes caused by a translucent strip at posterior of each tergite. Head warm, brownish black, antennae and mandibles completely orange. Legs mahogany, fading to orange at tarsi. Coxae mahogany proximally, switching to white halfway toward the femur. Pilosity: Body covered with scattered, thin, light-colored, standing hairs of various lengths, interspersed with silver recurved hairs. Pilosity predominantly on dorsal mesosoma, petiolar node, and all over head. Sculpturing: Head with fine punctures, becoming fingerprint-like whorls on mesosoma, legs, petiole, and gaster.

PARATYPES: TL 2.75–3.00, HL 1.05–1.27, HW 0.95–1.27, CI 90–101, SL 0.87-1.10, SI 74–105, PW 0.70–0.93, ML 0.37–0.47. Similar to holotype except heads more square in some and scapes extending beyond vertex by distance equal to the first two funicular segments in some.

Type Material
Type locality: The holotype worker was collected at Afetna Point on Saipan I., a member of the Commonwealth of the Northern Marianas Islands (CNMI). Paratype workers were collected on the islands of Tinian and Rota (also in CNMI).

Type series: Holotype worker and one paratype worker: Mariana Is.: Saipan I., Afetna Pt. (“No. 1026,” Townes, 1-VII-1946, NMNH). Other Paratypes (11): Mariana Is.: Rota I., Sabanna Monument (Bourquin, 2002); Tinian I. (“No. 493,” Townes, 6-VI-1946, NMNH)

Etymology
This species is named for the Mariana Islands, the only place where it has been collected to date.