Camponotus kaura

Known to nest in hollow twigs and dead stems.

Identification
Snelling and Torres (1998): Female castes. Head margins, in frontal view, subparallel and without standing setae between mandible base and dorsolateral angle; antennal scape without standing setae along shaft; free clypeal margin transverse, thin, and without median beveled area above margin; mandible with 6 teeth.

The material available is generally quite uniform in its features, the most obvious variation being in color. While the color is basically yellow or brownish yellow, the amount and intensity of infuscation of the head of the majors is quite variable. In some individuals, the lower two-thirds of the head may be blackish, but more usually the lower portions of the head are distinctly brown and the remainder is somewhat reddish.

One major worker, from the type nest sample, is unusual in that the head, the longest of any measured, is disproportionately slender for the major subcaste, with a CI of 123. This is the only major examined in which the CI exceeds 113.

This is by far the more common of the two species previously misidentified by Wheeler (1908) and all subsequent authors as Camponotus ustus. It is readily separated from Camponotus taino by the smooth malar area and lateral margins of the head, since both are devoid of erect setae. This species is separable from true C. ustus by the differences in head shape and clypeal structure as noted in the key and figures. In Puerto Rico, C. ustus is presently known only from Mona Island.

Distribution based on Regional Taxon Lists
Neotropical Region: Greater Antilles, Netherlands Antilles, Puerto Rico.

Known from Puerto Rico, Tortola and Guana Island, British Virgin Islands.

Nomenclature

 *  kaura. Camponotus kaura Snelling, R.R. & Torres, 1998: 5, figs. 7-12 (s.w.q.) PUERTO RICO.

Worker
Major worker, measurements (mm) (n=53): HW 1.88-2.16 (2.16); HL 2.10-2.48 (2.44); SL 1.45-1.66 (1.66); WL 2.5-2.9 (2.9); TL 7.5-10.5 (10.5). Ratios and indices: CI 105-123 (113); SI 67-72 (68); OI 20-22 (20); OMR 45-50 (50).

Head longer than wide in frontal view, sides straight or nearly so, weakly converging below, HW about 0.8 X UHW; dorsolateral lobes distinct and margin between them deeply concave. Eyes large and flat, their outer margins failing to attain lateral head margins by less than minimum diameter of antennal scape. Frontal lobes broad, greatest intercarinal distance about 0.4 X HW; upper intercarinal distance about 0.9 X greatest intercarinal distance. Clypeal midline subangular for most of its length; disc slightly depressed on either side above lower margin; free margin shallowly concave and with blunt median tooth; in profile, evenly sloping to ventral margin.

Antennal scape distinctly widened distad, extending to, or nearly to, level of dorsolateral lobe. Mandible with 6 teeth.

Front of head slightly to moderately shiny, surfaces finely tessellate; entire front of head sparsely and minutely punctate, clypeus least obviously punctate; mandible moderately shiny between sparse fine punctures that become finer, closer, and more elongate basad and along lower margin; short costae present distad at base of dentate margin. Posterior surface of head shinier, with sparse to scattered minute punctures and coarser, piligerous punctures.

Side of head (including malar area) in frontal view without erect setae; eyes bare; vertex and upper frons with several long setae on each side, outermost longest; frontal lobes with 3 long erect setae widely spaced along carinae. Clypeus with usual basal seta pair and 2 or 3 similar setae along each lateral margin; 4-8 short, erect submedian setae present; 4-6 long, slightly curled, flattened bristles present along ventral margin, extending over closed mandibles. Scape shaft without erect setae. Hypostomal area with 0-4 short erect setae.

Mesosoma robust, dorsum moderately convex in profile, metanotal depression weak; posterior declivity weakly concave. Pronotal dorsum about 1.2 X as wide as long and about 2.2 X as wide as propodeum at summit of declivity. Profemur about 3 X as long as deep.

Pronotum with about 10 long suberect to erect setae; longest about 0.4 X minimum eye diameter (MOD); mesonotum with (usually) 4 similar setae; summit of propodeal declivity with 1 pair of long, erect setae. Profemur with 2 or 3 widely spaced erect setae along ventral margin, longest no more than 0.5 X depth of femur; meso-and metafemora without erect setae along either dorsal or ventral margins; all femora with several setae at their apices; all tibiae without erect or suberect setae, but each with several bristles at apex; meso-and metatibiae without row of graduated bristles on flexor surfaces.

Petiole scale thin-cuneate in profile, summit narrowly rounded; summit, in posterior view, varying from weakly concave across middle one-half to weakly convex; summit with 2 or 3 erect setae on each side, longest subequal to longest pronotal setae.

Gaster moderately shiny, weakly transversely lineolate. T1 with 2 long submedian suberect setae at summit and usual marginal row; following segments with transverse median band of wide spaced erect setae in addition to marginal row, setae progressively longer on succeeding segments; appressed pubescence of terga widely scattered and extremely short (<0.03 mm long).

Color basically yellow; areas of varying extent on the head may be darker reddish or even brownish; similarly, metasomal terga may be weakly brown-banded.

Media workers, measurements (mm) (n=6): HW 1.29-1.70; HL 1.38-1.84; SL 1.17-1.35; WL 1.8-2.2; TL 5.8-6.7. Ratios and indices: CI 101-108; SI 74-89; OI 23-31; OMR 54-72.

Generally similar to major workers but head more quadrate and without pronounced dorsolateral lobes.

Minor workers, measurements (mm) (n=45): HW 0.85-1.27; HL 1.09-1.56; SL 1.19-1.62; WL 1.6-2.4; TL 4.6-6.6. Ratios and indices: CI 117-138; SI 104-113; OI 27-33; OMR 62-90.

Distinctly more slender bodied and with more elongate and parallel-sided heads, vertex evenly convex in frontal view; antennal scape clearly longer than head; free clypeal margin broadly convex.

Queen
measurements (mm) (n=11): HW 1.56-1.71; HL 1.78-1.94; SL 1.37-1.49; WL 3.0-3.4; TL 8.8-9.7. Ratios and indices: CI 111-117; SI 73-78; OI 28-33; OMR 79-97.

Head in frontal view less convergent below than in major worker, LHW about 0.75 X HW; vertex nearly straight across middle. Eyes large and extending slightly beyond head margins; EL about 0.8 X OMD; ocelli small, IOD about 4 X OD; OVD about 3 X OD (frontal view). Scape surpassing vertex by about 0.17 X SL. Sculpture and pilosity about as described above for major.

Mesosoma normally shaped for alate female. Dorsal face of propodeum only slightly shorter than declivitous face, abruptly rounded onto it and with 4-6 long setae near summit of declivity. Legs as described above.

Petiole and gaster about as described above.

Male
Males of the 3 species are similar: all are yellowish to brownish yellow, often with limited darker brownish areas on the head and mesosoma. They are similar in size, about 4.5-5.5 mm long. The smallest of the 3 species is Camponotus taino, in which males are seldom over 4.6 mm long, but some individuals up to 4.9 mm long have been seen; HW usually falls between 0.69-0.73 mm and occasionally reaches 0.76 mm. Males of the 2 remaining species, Camponotus kaura and Camponotus ustus, are usually about 5.4-5.6 mm long, but with some individuals above and below that range. In C. ustus, HW ranges between 0.88 and 0.95 mm; too few are available for a trend to be clear, but HW is usually over 0.90 mm. Males of C. kaura are a little smaller, with a HW ranging between 0.78 and 0.91 mm, and in over 90% of the 54 males measured it exceeded 0.80 mm, with over 70% falling between 0.82 and 0.91 mm.

The ocelli of C. kaura males are generally larger, and the 100 ranges between 1.5-2.5 X OD; in most examples, it is 2.2 or less. In both C. ustus and C. taino, the ocelli are smaller, and the IOD is 2.3-2.6 X OD, usually about 2.5 X OD.

Pilosity of the antennal scape is consistently different between the 3 species. In C. kaura, it consists exclusively of fine, fully appressed pubescence, except for several long, suberect distal setae. The scapal pubescence of C. taino, in contrast, is abundant, coarse, and subdecumbent to suberect; the setae are quite short, less than 0.025 mm long. Camponotus ustus is also provided with an abundance of similar short setae, but in addition there are scattered fine suberect setae that are about 0.08 mm long.

The metatibiae reflect similar differences: setae are fine and fully appressed in C. kaura, relatively coarse and subdecumbent to suberect and uniformly short in C. taino, and, finally, similar to C. taino, but with additional scattered longer setae in C. ustus.

Type Material
Holotype major worker, PUERTO RICO: Caño Gorda, 0-20 m, vic. Guánica, 26 Oct. 1991 (Snelling, Torres, and Canals, RRS #91-14), ex dead wood of black mangrove (Avicennia germinans), deposited in LACM. Paratypes: numerous workers, gynes, and males, same data, RRS #'s 91-14 to 91-17; workers, same data except from dead wood of Coccoloba (RRS #91-18); paratypes in, , ,.

Etymology
The specific name is a Taino (Arawak) word for a forest dweller; it is to be treated as a noun in apposition.

References based on Global Ant Biodiversity Informatics

 * Boer P. 2019. Ants of Saba, species list. Accessed on January 22 2019 at http://www.nlmieren.nl/websitepages/SPECIES%20LIST%20SABA.html
 * Garcia M. A. The vulnerability of leaflitter ants to forest disturbances in the islands of Puerto Rico, Greater Antilles. Novitates Caribaea 13: 74-91.
 * Snelling R. R. 2005. Wasps, ants, and bees: aculeate Hymeoptera. Pp. 283-296 in: Lazell, J. 2005. Island. Fact and theory in nature. Berkeley: University of California Press, xx + 382 pp.
 * Snelling R. R., and J. A. Torres. 1998. Camponotus ustus Forel and two similar new species from Puerto Rico (Hymenoptera: Formicidae). Contributions in Science (Los Angeles). 469: 1-10.