Camponotus chloroticus

Identification
Clouse et al. (2016) - Camponotus chloroticus was originally described by Emery (1897) as a subspecies of Camponotus maculatus, as follows: "I bought from Godeffroy Museum [Hamburg, 1861 - 1885] specimens of this form from the Tonga Islands and New Britain, under the name Camponotus pallidus. … For the shape of the various parts of the body, for the pubescence, the very weak sculpture and the hairs, it is very close to the Camponotus kubaryi, particularly the oceanic specimens and those from New Guinea. … Maximum size is 8 mm; reddish-yellow, dirt-like color; head darker and more red, abdomenmore or less blackish in its rear."

We do not know which aspects of the pilosity Emery noticed as being similar to that of Camponotus kubaryi, but the presence of standing hairs on the proximal hind femur and on the propleuron in both species is one of the few readily discernable synapomorphies of an important clade of Camponotus in the Pacific and one of the key characters used to distinguish C. chloroticus from Camponotus micronesicus. Using this pilosity character, overall similarity in size, shape, and coloration, as well as our finding of only one such yellow Camponotus species in the same islands, we confirm here that the Tongan Syntypes of C. chloroticus match the species in a clade that extends from New Guinea to Polynesia.

Distribution based on Regional Taxon Lists
Australasian Region: Australia, New Caledonia. Indo-Australian Region: Cook Islands, Fiji, New Guinea, Niue, Samoa, Solomon Islands, Tokelau, Tonga, Vanuatu, Wallis and Futuna Islands.

Biology
The phylogeography of a group of Pacific Island Camponotus species, which included a number of species groups, was broadly examined by Clouse et al. (2015). They found Camponotus chloroticus is a member of a clade (Clade IV) that tenuously appears to have originated in the Australian wet tropics but has undoubtedly spread and speciated across the Pacific Islands.

Nomenclature

 *  chloroticus. Camponotus maculatus subsp. chloroticus Emery, 1897d: 574 (w.) NEW GUINEA. Emery, 1914f: 424 (m.). Combination in C. (Myrmoturba): Emery, 1914f: 424; in C. (Tanaemyrmex): Emery, 1925b: 94. Subspecies of irritans: Emery, 1920c: 7; Karavaiev, 1933a: 316. Raised to species, senior synonym of chlorogaster, sanctaecrucis and material of the unavailable name samoaensis referred here: Wilson & Taylor, 1967: 93.
 * sanctaecrucis. Camponotus (Myrmoturba) maculatus subsp. sanctaecrucis Mann, 1919: 369, fig. 42 (s.) SOLOMON IS. Combination in C. (Tanaemyrmex): Emery, 1925b: 94. Subspecies of irritans: Emery, 1920c: 7. Junior synonym of chloroticus: Wilson & Taylor, 1967: 93.
 * chlorogaster. Camponotus (Myrmoturba) irritans subsp. chlorogaster Emery, 1920c: 7 (s.w.) VANUATU. [First available use of Camponotus (Myrmoturba) maculatus subsp. chlorotica var. chlorogaster Emery, 1914f: 429; unavailable name.] Combination in C. (Tanaemyrmex): Emery, 1925b: 94. Junior synonym of chloroticus: Wilson & Taylor, 1967: 93.

Worker
Clouse et al. (2016) - Majors: EL 0.48 (range 0.40 - 0.51), EW 0.36 (0.25 - 0.40), FCL 1.14 (1.00 - 1.31), HL 2.22 (1.85 - 2.40), HW 2.00 (1.45 - 2.25), ML 2.69 (2.38 - 2.85), MTL 1.68 (1.44 - 2.10), PH 0.74 (0.59 - 0.81), PL 0.58 (0.43 - 0.75), SL 1.65 (1.44 - 1.85); CI 90 (78 - 95), SI 83 (73 - 124). Mesosoma light yellow, gaster same color as mesosoma or slightly darker, head color usually darker than mesosoma; head tapering, vertex usually slightly concave; hind femur and propleuron with standing hairs. Minors: EL 0.42 (0.38 - 0.55), EW 0.33 (0.30 - 0.40), FCL 1.04 (0.90 - 1.40), HL 1.66 (1.55 - 2.10), HW 1.28 (1.18 - 1.60), ML 2.39 (2.20 - 3.05), MTL 1.58 (1.31 - 1.95), PH 0.62 (0.50 - 0.75), PL 0.57 (0.50 - 0.70), SL 1.80 (1.45 - 2.45); CI 77 (74 - 82), SI 142 (123 - 154). Mesosoma usually light yellow, gaster and head usually same color as mesosoma or slightly darker; head tapering, vertex convex and occipital carina present; hind femur and propleuron with standing hairs.

Type Material
Clouse et al. (2016) - The Camponotus chloroticus syntype from Irupara, New Guinea, is not as clearly aligned with the Tongan syntypes or modern specimens from the Polynesian, Fijian, and Melanesian clade, partially due to its mounting, which limits our view of the important pilosity characters. However, the New Guinean syntype has distinctly shorter scapes than almost all C. micronesicus specimens measured, measuring just at the lower limit of the range, and producing a scape index for the New Guinea syntype that is smaller than all C. micronesicus specimens measured but within the range for C. chloroticus. The petiole length of the New Guinean syntype is also similar to that of C. chloroticus specimens, and altogether we have more support for it being C. chloroticus than C. micronesicus. Other options for the identity of the New Guinean syntype include an undescribed from, or, if it is truly missing the hind femur and propleuron standing hairs, an oddly concolorous Camponotus humilior (which tends to be bicolorous); Camponotus novaehollandiae is too large, also usually bicolorous, and, from our PCA analysis, slightly different in shape