Camponotus mackayensis

Workers of this species have been found on trees as well as the ground in rainforests, mangrove and savannah woodland. All known nests have been found in dead twigs and branches.

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:

Dorsal surface of propodeum with shallow concavity. Sparse to plentiful erect, long setae on most surfaces, including scape.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 * . Camponotus reticulatus r. mackayensis Forel, 1902h: 506 (s.w.) AUSTRALIA (Queensland).
 * Combination in C. (Myrmamblys): Emery, 1925b: 139.
 * As unavailable (infrasubspecific) name: Forel, 1902h: 544.
 * Subspecies of reticulatus: Emery, 1925b: 139; Taylor & Brown, 1985: 118; Taylor, 1987a: 14; Bolton, 1995b: 109.
 * Status as species: McArthur & Shattuck, 2001: 36 (redescription); McArthur, 2007a: 302; McArthur, 2012: 102; McArthur, 2014: 48.

Major worker
In lateral view. Head: Red brown, anterior half coarsely punctate with plentiful short, whitish, sub-erect setae, posterior half smooth, glossy, with few shallow punctations; scape brown, funiculus lighter red brown; vertex with plentiful short setae, few shallow punctations; underside of head with short setae. Pronotum: Red brown, lighter than mesonotum, evenly convex, dorsum with few long and short setae. Mesonotum: Brown, evenly convex, dorsum with plentiful short setae. Metanotum: Distinct, wide, shallow groove. Propodeum: Brown, dorsum with few long setae, anterior dorsum marked by narrow ridge, otherwise straight; angle abrupt; declivity straight; ratio dorsum/declivity approximately 1; deeply striate near spiracle. Node: With few long setae, brown; anterior face lower half straight, upper convex; summit blunt; posterior face straight. Gaster: Brown, finely striate. Fore coxa: Mostly red brown with some yellow. Fore femur: Red brown, swollen. Fore tibia and tarsus: Red brown. Mid tibia: Outside with sparse flat-lying, short setae, without bristles inside. In dorsal view. Head: Sides straight tapering to front; vertex straight, slightly concave in some views; frontal area small, depressed and extended longitudinally; frontal carinae nearly parallel, anterior half diverging, posterior half wide; plentiful short, sub-erect setae on clypeus and cheeks. Clypeus: Oval shaped, widest at truncation, coarsely punctate, similar to cheeks; anterior margin projecting, convex, narrow, less than half head width at mandibles. Front or rear view. Node: Summit wide, straight, with few long setae.

Minor worker
In lateral view. Head: Red brown, side glossy with sparse short flat setae; scape red brown; funiculus lighter red brown; vertex with few long setae, underside of head without erect setae, with sparse, short, flat-lying setae. Pronotum: Red brown, lighter than mesonotum. Pronotum and mesonotum: Even convexity with few, very long setae. Metanotum: Distinct vee. Propodeum: Brown, dorsum with few scattered setae, anterior dorsum inclined upward to ridge, then shallow concavity to widely rounded angle; declivity mostly straight; ratio dorsum/declivity about 1.5; glossy, deeply striate near spiracle. Node: Brown with few long setae, without pubescence; anterior face mostly straight; summit rounded; posterior face straight. Gaster: Brown, glossy, finely striate. Fore coxa: Mostly red brown with some yellow. Fore femur: Swollen. Tarsus: Red brown. Mid tibia: Red brown with sparse, flat-lying setae, without bristles inside. In dorsal view. Head: Sides, anterior half tapering to front; vertex flatly convex between widely rounded corners; scape sometimes with few long setae; frontal carinae diverging wide; frontal area depressed; max HW posterior to eye centre; five coarse teeth visible. Clypeus: Glossy with few long and short, scattered flat-lying setae; carina indistinct; anterior margin convex, projecting. In front or rear view. Node: Summit wide, straight with few long setae.

Measurements
PW 0.80-1.05 mm, HT 0.7-1.15 mm, 14W 1.00- 1,15 mm, HL 1.00-1.70 mm, CAR W 0.8 mm, CLY W 0.4-0.45 mm, TL 0.8-1.0 nun.

Length 4-7 mm. Worker major. A close neighbor of yerburyi Forel of Ceylon, but head is distinctly narrower in front, shorter and wider behind; mandibles are bigger. The coarse pits at the front of the head are stronger, more abundant and extend to the eyes and on part of the front. Head is excavated behind, the scape, which scarcely reaches the occiput in yerburyi, exceeds it slightly in mackayensis. Mesonotum is not weakly bordered; it is followed by an intermediate segment in a the form of a transverse round swelling which is lacking in yerburyi. The basal face is wider and shorter and hollowed out into a saddle at least as much as in yerburyi. The segments of the gaster have a wide rim of brilliant golden yellow. Thorax is much more convex from front to back. Gaster silky (glistening), sculpture very fine and very dense (striate or wrinkled transversely) otherwise the sculpture is like yerburyi. Pilosity a little more sparse, no where on the tibias. Anterior half of the head,funicles and base of the scapes a testaceous light red; the rest is black, with limbs and the other half of the scapes brown. Worker minor. The head is wider behind than yerburyi; basal face of the metanotum(= propodeum) is wide, profoundly excavated in a saddle. Mesonotum with a margin. The anterior border of the basal face is raised up, which forms a slight meso-metanotal indentation which does not exist with yerburyi. Mandibles and front of the clypeus are the only reddish parts of the head. Otherwise like the major worker. Mackay, Queensland (Turner)

References based on Global Ant Biodiversity Informatics

 * Andersen A. N., M. Houadria, M. Berman, and M. van der Geest. Rainforest ants of the Tiwi Islands: a remarkable centr of endemism in Australia's monsoonal tropics. Insectes Sociaux 59: 433-441.
 * McArthur A.J., and S. O. Shattuck. 2001. A taxonomic revision of the Camponotus macrocephalus species group (Hymenoptera: Formicidae) in Australia. Trans. R. Soc. S. Aust. 125: 25-43.