Cataulacus vorticus

The nest from which Nigerian specimens were taken was situated in and under the bark of a cocoa tree, at the junction of two main branches about 5 ft above ground level. The tree bark on and in the vicinity of the nest was covered with moss.

Identification
Cataulacus vorticus is closely related to Cataulacus brevisetosus and like that species it possesses clavate cephalic and clypeal hairs. It is separable by the armament of the pronotum which here consists of but a single tooth whilst in brevisetosus there is a row of denticles on each side. (Bolton 1974)

Distribution
This taxon was described from Nigeria. It is also found in Kenya and Uganda.

Nomenclature

 *  vorticus. Cataulacus vorticus Bolton, 1974a: 38, figs. 16, 19 (w.q.m.) NIGERIA.

Worker
Holotype. TL 3.5, HL 0.90, HW 0.82, CI 91, EL 0.42, OI 51, IOD 0.64, SL 0.44, SI 54, PW 0.56, AL 0.94, MTL 0.44.

Occiput and vertex meeting through a continuous convexity, occipital crest absent. Occipital corners with a bluntly triangular small tooth and with a denticle close to the tooth upon the occipital margin. Sides of head behind eyes shallowly convex, minutely and irregularly denticulate. Preocular tooth small, broadly triangular, separated from the eye by a smaller, rounded prominence. Pronotum weakly marginate laterally, the humeral angles acute and prominent, dentiform in dorsal view. A single tooth is present on the pronotal margin, close to the junction with the mesonotum. Between the humeral angles and this tooth the margin is smooth, very shallowly concave and without denticles. Sides of mesonotum scarcely or not marginate, without denticles; the propodeum similar and armed with a pair of spines. Dorsal surface of alitrunk without sutures or impressions; sides of alitrunk gradually convergent behind the pronotal tooth. In profile the anterior and posterior surfaces of the petiole strongly convergent dorsally, meeting in what is virtually a right-angle; the petiole without a differentiated dorsal face. Anterior face of postpetiole vertical, the posterior face almost so, the dorsal surface convex. Subpetiolar process simple, with a sharp posteroventral angle. Subpostpetiolar process simple, short, bluntly digitiform. First gastral tergite not marginate laterally.

Dorsum of head with a fine rugoreticulum everywhere, the interspaces finely and densely but shallowly reticulate-punctate, dully shining. Pronotal dorsum similarly but more densely sculptured, the reticulae close together and with a predominantly longitudinal trend. On the mesonotum and propodeal dorsum the rugae are fine and mostly longitudinal, more distinct upon the propodeum; the whole surface finely and quite strongly reticulate-punctate. Declivity of propodeum smooth and shining with scattered, very faint punctures. Petiole with some faint longitudinal rugulae; the postpetiole predominantly densely punctate but with a few faint rugules. First gastral tergite finely and densely reticulate-punctate.

Hairs on clypeus and remainder of the cephalic dorsum strongly clavate, the hairs longer and more distinct upon the clypeus than elsewhere. Dorsal surfaces of alitrunk, pedicel, appendages and gaster with numerous short, very fine, simple hairs, difficult to see on the alitrunk under low magnification.

Paratype. TL 3.4 – 3.5, HL 0.84 – 0.90, HW 0.74 – 0.82, CI 88 - 93, EL 0.38 – 0.44, OI 50 - 54, 10D 0.54 – 0.62, SL 0.40 – 0.44, SI 51 - 54, PW 0.52 – 0.56, AL 0.92 – 0.94, MTL 0.42 – 0.44 (3 measured).

As holotype but in the smallest the sides of the head behind the eyes lack denticles and the humeral angles are not as prominent. The subpetiolar process is clearly visible in one specimen and has the anteroventral angle broadly rounded.

Queen
Paratype. TL 4.2 – 4.4, HL 1.00, HW 0.82 – 0.84, CI 82 - 84, EL 0.44 – 0.46, OI 53 - 55, IOD 0.62 – 0.66, SL 0.44, SI 52 - 54, PW 0.72 – 0.76, AL 1.22 – 1.26, MTL 0.44 – 0.46 (4 measured).

Similar to worker but with denticulation of sides of head behind eyes very much reduced or absent. Humeral angles as well developed as in worker but the tooth near the promesonotal junction absent. Propodeal spines short and blunt. Sculpturation of mesoscutum and propodeal dorsum longitudinal, that of the latter stronger than that of the former.

Male
Paratype. TL 3.8 – 4.0, HL 0.64 – 0.72, HW 0.64 – 0.72, CI 100 - 103, EL 0.28 – 0.34, OI 44 - 47, IOD 0.50 – 0.58, SL 0.28 – 0.30, SI 42 - 44, PW 0.64 – 0.68, AL 1.14 – 1.30, MTL 0.46 – 0.54 (4 measured).

Occipital crest absent; occipital corners acutely angled but not dentate. Sides of head behind eyes not denticulate. Humeral angles acute, dentiform in dorsal view, the remainder of the pronotal margins unarmed, shallowly concave and divergent posteriorly. Anterior arms of notauli strongly developed and cross-ribbed, the posterior arm a very weak impression or absent. Parapsidal furrows very strongly marked, impressed. Sides of remainder of alitrunk not denticulate, the propodeum with a pair of short, acute teeth. Head predominantly rather coarsely reticulate-punctate, with some fine overlying rugulae. Pronotum, mesoscutum and scutellum reticulate-punctate with few or no rugulae. In one specimen the scutum has extensive smooth shiny patches surrounding the apical portions of the parapsidal furrows. Propodeal dorsum longitudinally rugose with reticulate-punctate interspaces; the petiole and usually the postpetiole similarly but much more finely sculptured; or the latter lacking distinct rugulae. First gastral tergite finely and densely reticulate-punctate or merely reticulate, dully shining. Hairs numerous on all dorsal surfaces, everywhere fine and simple.

Type Material
Holotype worker, NIGERIA: Gambari, under bark of cocoa tree, 30.viii.1969 (B. Bolton) (BMNH).

Paratypes. 2 workers, 4 females, 3 males, same data as holotype (BMNH and MCZ, Boston). 1 worker, 1 male, ZAIRE: 91 miles W. of Popokabaka, 2.viii.1957 (E. S. Ross and R. E. Leech) (MCZ, Boston).

Additional References

 * [[Media:Bolton 1974a.pdf|Bolton, B. 1974a. A revision of the Palaeotropical arboreal ant genus Cataulacus F. Smith (Hymenoptera: Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 30: 1-105 PDF]]