Camponotus ustus

This species has been collected numerous times. Its biology remains unknown.

Identification
Snelling and Torres (1998): Female castes. Head margins (major) distinctly convergent below or (media, minor, gyne) subparallel, without standing setae between mandible and dorsoiateral angle; antennal scape with sparse erect setae along shaft; free clypeal margin transverse, thick and with median, broadly triangular beveled area; mandible with seven teeth (sometimes obscurely so).

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Dominican Republic, Greater Antilles, Grenada, Haiti, Puerto Rico.

Nomenclature

 *  ustus. Camponotus ustus Forel, 1879a: 75 (s.w.q.m.) ANTILLES. Wheeler, G.C. & Wheeler, J. 1974a: 61 (l.). Combination in C. (Myrmoturba): Forel, 1914a: 267; in C. (Pseudocolobopsis): Emery, 1920b: 259; in C. (Tanaemyrmex): Wheeler, W.M. 1936b: 205. Senior synonym of depolitus, furnissi, larvigerus, maculifrons, sublautus, ulysses: Snelling, R.R. & Torres, 1998: 2.
 * ulysses. Camponotus ustus var. ulysses Forel, 1907e: 11 (s.w.q.m.). HAITI. Combination in C. (Pseudocolobopsis): Emery, 1925b: 158; in C. (Tanaemyrmex): Kempf, 1972a: 73. Junior synonym of ustus: Snelling, R.R. & Torres, 1998: 2.
 * furnissi. Camponotus ustus var. furnissi Wheeler, W.M. & Mann, 1914: 55 (s.w.q.) HAITI. Combination in C. (Pseudocolobopsis): Emery, 1925b: 158; in C. (Tanaemyrmex): Kempf, 1972a: 73. Junior synonym of ustus: Snelling, R.R. & Torres, 1998: 2.
 * larvigerus. Camponotus larvigerus Wheeler, W.M. & Mann, 1914: 52, fig. 23 (s.w.q.) HAITI. Combination in C. (Myrmoturba): Forel, 1914a: 267; in C. (Tanaemyrmex): Emery, 1925b: 81. Junior synonym of ustus: Snelling, R.R. & Torres, 1998: 2.
 * sublautus. Camponotus ustus var. sublautus Wheeler, W.M. & Mann, 1914: 55 (s.w.) HAITI. Combination in C. (Pseudocolobopsis): Emery, 1925b: 158; in C. (Tanaemyrmex): Kempf, 1972a: 73. Junior synonym of ustus: Snelling, R.R. & Torres, 1998: 2.
 * maculifrons. Camponotus (Tanaemyrmex) larvigerus var. maculifrons Menozzi & Russo, 1930: 167 (s.w.) DOMINICA. Junior synonym of ustus: Snelling, R.R. & Torres, 1998: 2.
 * depolitus. Camponotus (Tanaemyrmex) ustus var. depolitus Wheeler, W.M. 1936b: 205 (s.w.m.) DOMINICA. Junior synonym of ustus: Snelling, R.R. & Torres, 1998: 2.

Worker
Snelling and Torres (1998): Major worker, measurements (mm) (n=30): HW 1.64-2.26 (2.04); HL 1.95- 2.46 (2.14); SL 1.95-2.05 (-); WL 2.6-3.1 (-); TL 7.5-8.7. Ratios and indices: CI 105-119 (105); SI 83-103 (-); OI 20-25 (24); OMR 48-60 (56). Note: due to the poor condition of the one major worker in the syntypic series some measurements were not possible, hence the (-).

Head slightly longer than wide in frontal view, sides gently curved and strongly convergent below, LHW about 0.68 X HW; vertex concave between distinct dorsolateral lobes. Eyes relatively small and, in frontal view, outer margins short of lateral head margins by more than minimum diameter of scape. Frontal lobes narrow, greatest intercarinal distance about 0.32 X HW; upper intercarinal distance about 0.8 X greatest intercarinal distance. Clypeal midline weakly subangulate for most of its length, terminating below in broadly triangular median beveled area; free (ventral) margin thick, straight between obtuse lateral angles. Antennal scape moderately broadened distad, apex well beyond summit of dorsolateral lobes; mandible with 7 teeth.

Front of head shiny, surfaces coarsely tessellate, clypeus and lower malar area less shiny, more finely tessellate; entire front of head sparsely and minutely punctate, clypeus with few fine punctures but with coarser setigerous punctures. Mandible about as shiny as clypeus, with obscure minute punctures and scattered coarser setigerous punctures. Posterior surface of head shinier between sparse to scattered minute punctures and coarser piligerous punctures.

Side of head (including malar area) without erect setae; eyes bare; vertex and upper frons with 3-5 erect setae on each side, outermost shortest; frontal lobes with 5 long erect setae along each margin and shorter submedian dorsal pair. Clypeus with usual basal seta pair and 4-6 similar discal hairs; usual fringe of widely spaced long curled setae along free margin; hypostomal area with 2-4 short erect setae. Distal two-thirds of scape shaft with variable number of short erect setae that are shorter than distance between them.

Mesosoma robust, dorsum moderately convex in profile, metanotal depression absent; propodeum strongly curved and without definite posterior declivity. Pronotal dorsum about 1.1 X as wide as long and almost 4 X as wide as propodeum at summit of "declivity." Profemur about 3.5 X as long as deep.

Pronotum with 4-6 long erect setae on each side that are weakly inclined forward, longest about 0.9 X MOD; mesonotum with (usually) 3 seta pairs, middle pair longest; summit of propodeal "declivity" with 4 or 5 long setae. Profemur with 1-3 long setae on posterior face and about 6 well-spaced, short setae along ventral margin, longest about 0.20 X depth of femur; meso- and metafemora each with variable number of ventral setae on basal one-fourth to one-third; tibiae without erect or suberect setae; meso- and metatibiae without row of graduated bristles along flexor surface.

Petiole scale thin-cuneate in profile, summit acute; summit, in posterior view, broadly and evenly convex; summit with 3-4 long setae on each side, longest at least subequal to longest pronotal setae.

Gaster moderately shiny, weakly transversely lineolate. T1 with 2 or 3 weakly defined rows of long discal setae in addition to marginal row; longest setae at summit of basal declivity longer than MOD; each following tergum with 1-3 ill-defined transverse rows of long setae.

Color yellowish to brownish or reddish yellow, usually with lower face and frons conspicuously darker; mesosoma with varying degrees of infuscation; terga more or less brown banded.

Media and minor workers, measurements (mm) (n=45): HW 1.07-1.41; HL 1.49-1.80; SL 1.79-1.96; WL 2.3-2.7; TL 6.2-7.7. Ratios and indices: CI 127-141; SI 109-122; OI 27-28; OMR 65-71. Generally similar to major workers, but more slender and with more elongate and parallel-sided heads that lack defined dorsolateral lobes.

Queen
From Snelling and Torres (1998): measurements (mm) (n=6): HW 1.58-1.86; HL 1.84-2.12; SL 1.68-1.90; WL 3.4-3.8; TL 10.1-10.7. Ratios and indices: CI 114-119; SI 87-90; OI 29-32; OMR 83-91.

Head margins less convergent below than in major worker, LHW about 0.74 X HW; vertex weakly convex and without defined dorsolateral lobes. Eyes large and extending slightly beyond head margins in frontal view; ocelli small, IOD about 3 X OD; OVD (frontal view) about 2.5 X OD. Scape surpassing vertex margin by about 0.3 X SL. Sculpture and pilosity about as described above for major.

Mesosoma normal-shaped for alate female. Propodeum with short dorsal face, broadly rounded into declivity and with several (4-6) long setae slightly above middle of declivity. Legs as described above.

Petiole and gaster about as described above.

Male
From Snelling and Torres (1998):

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
Soldier, worker, gyne, male. St. Thomas, B.W.I.; syntypes.