Colobopsis sanguinifrons

A.J. McArthur and R. Eastwood collected an alate female at Leslie Dam, Eatonsville, New South Wales at 10 p.m. on 29 Nov. 1997. This suggests that nuptial flights of this species might occur near the last week in November.

Identification
A member of the Camponotus macrocephalus species-group. This group has the following characters:


 * Fore femurs swollen, much greater in diameter than middle and hind femurs, generally more swollen than in most other Camponotus species.
 * Spines or bristles on the lower surfaces of the tibiae lacking, or at most, only one or two (most Camponotus species possess two rows of 5 to 10 spines).
 * Major workers and queens with the anterior of the head is truncated and flattened (phragmotic).
 * Major and minor workers present, but not intermediate-sized workers (worker caste dimorphic).

Within this group, this species can be diangosed as follows:

Minor worker with a few long, erect setae on underside of head, few more on gaster and none elsewhere. Dorsal surface of propodeum about three times as long as declining surface. Major differs greatly from minor. In major worker, anterior regions of head clothed in plentiful short, clavate setae, particularly on and near truncation; absent from posterior regions; few long setae on underside of head, coxa and gaster.

In this species the major workers and queens possess plentiful distinctive short, clavate setae on the anterior head. Setae on the anterior head of minor workers are sparse, longer, uniform diameter and not clavate. (Clavate setae resemble a forest of miniature matches with enlarged extremities.) Such clavate setae are uncommon in Camponotus although Donisthorpe (1948) refers to similar clavate setae in Colobopsis excavata from Maffin, West Irian, Indonesia.

Distribution based on Regional Taxon Lists
Australasian Region: Australia. Indo-Australian Region: New Guinea.

Nomenclature

 *  sanguinifrons. Camponotus (Colobopsis) sanguinifrons Viehmeyer, 1925b: 143 (s.w.) AUSTRALIA. Combination in Colobopsis: Ward, et al., 2016: 350. See also: McArthur & Shattuck, 2001: 39.

Major worker
In lateral view. Head: Posterior dark brown, anterior red; posterior without pilosity, anterior with dense, fine, short, white, clavate setae (Fig. 2) especially on cheeks and clypeus; antennae red brown; underside of head with few long setae. Mesosoma and node: Dark brown without pilosity, glossy, finely striate. Pronotum: Anterior quarter straight, next quarter rounded, then flatly convex. Posterior half of pronotum, mesonotum, metanotum and dorsum of propodeum form uninterrupted gentle curve. Metanotum: Wide, marked by two transverse sutures. Propodeum: Angle about 150°; declivity mostly straight; ratio dorsum/declivity about 1.5. Node: Anterior face lower half straight, otherwise convex; summit rounded; posterior face straight, inclined forward. Limbs: Lighter coloured than mesosoma, fore femur swollen. Mid tibia: With short, sparse, flat-lying setae, without bristles inside. In dorsal view. Head: Sides straight, parallel; vertex mostly straight, scape with indistinct, flat, short, sparse setae; frontal carinae wide, short, straight, diverging behind; anterior head truncated, clypeus mandibles and cheeks forming flat circular area coarsely punctate with few coarse longitudinal striations and central keel; plentiful short, erect, stubble-like, clavate setae; clypeus lateral margins widest at centre of circular area; frontal area extended laterally at truncation. Clypeus: Anterior margin well posterior to mandible insertions, straight, short. In front or rear view. Node: Summit flat, wide.

Minor worker
In lateral view. Dark brown, limbs, anterior head and antennae a little lighter coloured. Head: Side glossy without pilosity, finely striate; vertex with a few long setae, underside of head without pilosity. Mesosoma: Without pilosity, finely striate, reticulate. Pronotum: Anterior half convex, posterior half straighter. Mesonotum: Anterior and posterior sixths inclined, centre flatly convex. Metanotum: Shallow trough, spiracle well below dorsum. Propodeum: Dorsum anterior quarter inclined upward, otherwise straight and sloping downward; angle rounded 135°; declivity upper half straight, lower half strongly concave; ratio dorsum/declivity approximately 3; spiracle situated well forward of declivity and midway between dorsum and coxa. Node: Without pilosity, anterior and posterior faces parallel, anterior face short, straight; summit sloping upward rounded; posterior face straight, longer than anterior. Caster: Finely striate, scattered upstanding setae without visible pubescence. Fore femur: Swollen. Mid tibia: Sparse, fine, flat-lying setae, without bristles inside. In dorsal view. Head: Sides straight, tapering slightly to front; vertex flat with rounded corners; scape with indistinct, sparse, fine, flat-lying setae; frontal carinae short, wide; frontal area indistinct; max HW near eye centre. Clypeus and cheeks: Finely reticulate with few setae; carina distinct posteriorly; anterior margin projecting, evenly convex, wide. in front or rear view. Node: Summit straight; without pilosity.

Measurements
PW 0.45 — 0.55 mm, HT 0.55 — 0.65 mm, EL 0.20- 0.22 mm, HW 0.75 - 1.10 mm, HL 0.85 — 1.40 mm, CAR W 0.4 mm, CLY W 0.38 mm, TL 0.72 -0.75 mm, NW 0.2 - 0.25 mm.

Worker Major. Similar to C. truncatus but likewise rufifrons at least belonging to the species of Mayr yet very different from the specimens in the Godeffroy Museum. Head somewhat shorter than truncatus without the quadratic surface, even a trace broader than long with the mandibles closed 4:3. Sides straight, posterior weakly tapering, posterior corners strongly rounded. Base rather circle shaped, concave, which through the sculpture seems finely curved as with truncatus. Clypeus twice as long as wide, with parallel sides, anterior and posterior equally wide, without a keel. Frontal area and frontal margin lacking. At the frontal area there is sometimes a somewhat stronger raised up lengthwise crease. Frontal ridges are widely separated, diverging towards the back and reaching to the height of the eye surrounds. The scape extends beyond the posterior margin of the head by almost double the thickness of the shaft; The shaft a little narrower than truncatus. The eyes taking up 1/4 of the length of the sides of the head, their posterior edge 1/2 quarter distant from the end of the head. Mandibles short and wide the outer edge weakly bent, the A border with 5 teeth, the inner third smooth. Thorax as long as the head, rather like truncatus, somewhat narrower; Promesonotal-Mesoepinotal suture distinct, sometimes weaker, sometimes more strongly impressed, Metanotum hardly at all or more less distinctly bordered; Epinotum angle quite rounded. The node of the petiole twice as wide as long scarcely higher than wide, in profile almost parallel sided, above rather elevated without an outer edge. The anterior head sculptured much finer and evenly as with truncatus: the mid part very thickly and finely wrinkled along, in between punctations; the sides and the mandibles with quite flat dimples, wrinkled almost netlike, each dimple or each punctation with one hair, the base overall being finely reticulate, completely matte. The front part of the head up to the middle of the head wrinkled lengthwise, the wrinkles combined with multiple reticulation, in addition to the hairs in the spots and the finely netted basic sculpture; posterior of the head only thickly netted with scattered spots, matte. All above finely netted and glossy. Upstanding covering of hair short and scattered, more plentiful on the head, lacking on the limbs, flat lying hair not visible, also on the limbs and scape only microscopic and sparse. Brownish black; anterior head and mandibles blood-red, scape, femurs and tarsi more or less brown, the joints always lighter, segments of the gaster whitish lined. Length 4.5-5.5 mm. Worker Minor Head rectangular, 1/5 longer than wide, sides very weakly curved slightly tapering, strongly rounded posterior corners. The head in profile is biconvex, in front not raised up. Clypeus weakly keeled, the anterior edge convex. Eyes still bigger than the.major worker. Scape extends over the posterior head by a good quarter. Mandibles with 3 visible teeth. Thorax much longer than the head with relatively long epinotum and distinctly narrower than truncatus, the epinotum laterally somewhat more compressed, but in length not so narrow as sommeri. The suture is distinct like the Major worker, the sloping surfaces of the epinotum very short. The petiole a little longer than the major worker. The whole body is finely reticulate, glossy, the mandibles almost smooth. Upstanding covering of hair quite distinct, also on the head and longer than with the major.worker; flat lying lacking. Blackish-brown, the mandibles and the narrow seam on the anterior border bright yellow, or reddish yellow, the first 2/3 of the scape and the tarsi more or less brownish yellow. Length 3.5--4 mm. Trial Bay, from burned wood from the forest. The minor.worker is quite different but certainly belongs to the Major worker. C rufifrons is quite different. The head is broader, the whole animal altogether sturdier. The head anterior and posterior equally broad,the sides weakly convex. Truncated surface oval crosswise. The clypeus wider, anterior tapering, the posterior reaching a little over the untruncated part of the head. Sculpture of the anterior head much coarser, no basic reticulation, between the forehead striations much less coarsely wrinkled. Thorax much stronger, Pronotum half as wide as the Mesonotum (with sanguinifrons only very slight), Mesonotum towards the back only slightly narrowed (strong with sanguinifrons) Metanotum very short, but on both sides very sharply restricted (with sanguinifrons not or indistinctly restricted and then much longer), Epinotum not much narrower than the anterior Mesonotum (with sanguinifrons almost 1/3 of the anterior Mesonotum), a distinctly blunter Epinotum angle, declivity somewhat longer than the basal surface. Petiole broader and longer. There is quite different coloring. Whether C.rufifrons Mayr really corresponds with F.Smith's type must remain open to question.

References based on Global Ant Biodiversity Informatics

 * Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
 * Klimes P., and A. McArthur. 2014. Diversity and ecology of arboricolous ant communities of Camponotus (Hymenoptera: Formicidae) in a New Guinea rainforest with descriptions of four new species. Myrmecological News 20: 141-158.