Camponotus spenceri

Identification
McArthur and Leys (2006) - Camponotus maculatus group species share the following distinguishing characters: 1. The most striking character is the distinct occipital carina in minor workers (see the dorsal head view of the minor worker in the caste images of Camponotus crozieri). This forms a ridge externally and probably serves to strengthen the anterior parts of the head (Snodgrass 1935), it is absent in major workers. 2. Strong dimorphism, i.e., workers encountered are mostly either major or minor, medium workers are non existent or very scarce. 3. The sides of the heads of major workers taper strongly to the front (Fig. 2) while in minor workers, the sides are mostly parallel and taper to the rear. 4. The vertex in major workers is concave or flat, in minor workers it is convex. 5. The scape and tibiae have plentiful short setae, raised up, more so in Australian than in African species. 6. Biology: (a) mostly nocturnal, (b) nests are at honey bait, (e) quickly scatter when disturbed by torch light.

Distribution based on Regional Taxon Lists
Australasian Region: Australia. Indo-Australian Region: Borneo, Indonesia, Malaysia. Palaearctic Region: China.

Nomenclature

 * reticulatus. Camponotus reticulatus Kirby, W.F. 1896: 204 (s.w.) AUSTRALIA (Northern Territory).
 * [Junior primary homonym of Camponotus reticulatus Roger, 1863a: 139.]
 * Replacement name: Camponotus (Tanaemyrmex) spenceri Clark, 1930c: 18.
 * . Camponotus (Tanaemyrmex) spenceri Clark, 1930c: 18.
 * [Misspelled as spenseri by McArthur, 2007a: 296.]
 * Replacement name for Camponotus reticulatus Kirby, W.F. 1896: 204. [Junior primary homonym of Camponotus reticulatus Roger, 1863a: 139.]
 * Status as species: Taylor & Brown, 1985: 119; Taylor, 1987a: 15; Bolton, 1995b: 124; McArthur, 2007a: 329; McArthur, 2010: 100; Pfeiffer, et al. 2011: 38 (error); Guénard & Dunn, 2012: 30 (error); McArthur, 2014: 94.
 * [Note: Pfeiffer, et al. 2011: 38, and Guénard & Dunn, 2012: 30, include spenceri Clark in error as a species of Borneo and China, respectively; spenceri is the replacement name for reticulatus Kirby, W.F. 1896 (Australia), not for reticulatus Roger, 1863a (Oriental region).]

Description
Length.-Major worker, 9 mm; smaller worker, 6 mm. Larger worker.-Dark pitchy-brown, inclining to rufotestaceous; mandibles ferruginous, antennae, tarsi, and under surface of legs reddish; abdomen with a white stripe on each side intersecting the white incisions; mandibles about twice as long as broad at the base, gradually curved, pointed at the tip, and armed with six large teeth, in addition to the long terminal tooth; clypeus carinated, about as broad as long, the sides subrotund, the upper and lower extremities concave. Outer antennal ridges slightly waved, but diverging above, and neither these nor the central one attain the summit of the vortex. Head very convex behind, thorax sloping, gradually narrowed behind; thorax and abdomen sparsely clothed with thick, raised hairs. Antennae and legs clothed with short hair; legs moderately long and slender, with a very strong, pale terminal spine on the tibia. Petiole large, conical, sloping slightly forward.The small workers are nearly black, with the scape of the antennae and the tarsi rufotestaceous, and the incisions of the abdomen pale. Paisley Bluff, burrow-nest under stones, many specimens; also Palm Creek and Finke Gorge. I cannot make this conspicuous species agree with any of the specimens or descriptions before me, though it somewhat resembles C. testaceipes, Smith. It is possibly a honey ant, but the carinated clypeus is alone sufficient to separate it from C. inflatus, Lubbock.

Camponotus (Tanaemyrmex) spenseri Clark, J. (1930) This appears to be a valid species, but Kirby's name having been preoccupied by Roger, 1863 (Berl. Ent. Zeitschr., vii, p. 139). I have substituted the name of the late Sir Baldwin Spencer, leader of the expedition, for the species. the major and minor workers are here more fully described as Camponotus (Tanaemyrmex) spenceri, nom. nov. Worker Major.-Length 8.5-9 mm. Reddish brown. Mandibles red. Funiculus, tarsi and apical margin of the segments of the gaster testaceous. Subopaque. Mandibles shining, very sparsely punctate. Head, thorax, node and first segment of the gaster finely and densely punctate-reticulate, the rest of the gaster microscopically punctate. Hair reddish, long and erect,moderately abundant throughout. Head very slightly longer than broad, much broader behind than in front, the occipital border straight, the sides convex. Frontal carinae diverging slightly behind, one fourth longer than their width at the middle; there is a strong carina between them. Clypeus convex above, strongly projecting at the middle in front, this portion of the clypeus as long as broad, strongly carinate, the anterior border concave. Eyes convex, placed at the posterior third of the sides. Scapes extending beyond the occipital border by one-fourth of their length; segments one to four of the funiculus almost equal in length, the others subequal. Mandibles large and triangular, armed with six strong sharp teeth. Thorax almost two and half times longer than broad. Pronotum one-third broader than long, strongly convex in front on the sides and above. Mesonotum circular, convex above. Epinotum narrow above, fully twice as long as broad. Node scale-like, convex in front, concave behind; in profile inclined forward, then anterior face strongly convex, posterior flat, bluntly pointed above. Gaster longer than broad. Legs long and slender. Worker minor. Length 6-7.3 mm. Color, sculpture and pilosity similar to the worker major. Head longer than broad, as broad in front as behind, the occipital border strongly, the sides feebly, convex. Scapes extending beyond the occipital border by half their length. the rest as in the major, but much more slender. Habitat.-Paisley Bluff, Palm Creek, Finke Gorge.

References based on Global Ant Biodiversity Informatics

 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * McArthur A. 2010. A guide to Camponotus ants of South Australia. Adelaide: South Australian Museum, IV + 121 pp.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
 * Yusah K. M., T. M. Fayle, G. Harris, and W. A. Foster. 2012. Optimizing diversity assesment protocols for high canopy ants in tropical rain forest. Biotropica 44(1): 73-81.