Cyphomyrmex vorticis Weber

Kempf, W. W., 1966, A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part II. Group of rimosus (Spinola) (Hym. Formicidae)., Studia Entomologica (N. S.) 8, pp. 161-200 : 188-190

11. Cyphomyrmex vorticis Weber

(Figs. 1, 15, 34, 44)

Cyphomyrmex vorticis Weber , 1940: 409-10 (Worker; Bolivia: Santa Helena).

Types. - Workers taken by W. M. Mann at Santa Helena, Bolivia, in August 1921. A single specimen (lectotype NAW) seen.

Worker (lectotype). - Total length 3.8 mm; head length 0.88 mm; head width 0.85 mm; thorax length 1.28 mm; hind femur length 1.28 mm. Medium brown; dorsum of head, scapes, tibiae and gaster darker with ferruginous hues. Integument opaque; densely and minutely punctate-granulate.

Head as shown in Fig. 1. Mandibles finely reticulaterugulose, somewhat shining; chewing border with a broader diastema between 2nd and 3rd basal tooth. Clypeus with flattened anterior apron, the border of which is gently convex and notched in the middle; on each side it bears a prominent tooth. Frontal lobes very broadly expanded, the anterior curvature stronger than the posterior one; upper surface with a depressed circular area above the antennal socket. Frontal carinae sigmoidal, not quite reaching occipital corner, their border somewhat elevated at place of greatest constriction. Front with a feeble tumulus at frontal area, followed by a transverse shallow depression. Carinae of vertex semicircular, having as center a prominent tubercle; from there they diverge both cephalad and caudad. Occipital corners strongly dentate, tooth curving slightly upward and outward. Occiput oblique, not perpendicular. Preocular carina curving mesad above eyes. Postocular carina beginning below eye and extending backwards to the prominent supraocular tooth. Eyes with about 11-12 facets across greatest diameter. Inferior border of cheeks strongly and irregularly crested. Scapes gradually incrassate toward apex, surpassing the occipital corner by more than their maximum width. All funicular segments longer than broad, segment I as long as II and III combined.

Thorax as shown in Fig. 15. Pronotum with small median, stronger lateral teeth; the latter connected with the feebly marked humeral angle by a blunt carina; antero-inferior tooth rectangular. Mesonotum with strong paired conical anterior teeth, followed by another pair of low elongate and blunt tubercles. Mesoepinotal constriction deep. Basal face of epinotum flanked by sharply carinate ridges in its entire length; space between ridges shallowly excavate. Declivous face laterally immarginate. Lateral blunt and oblique welt well developed, bearing the spiracle. Hind femora (Fig; 44) angular beneath in front of basal third, then gradually tapering toward apex; the postero-ventral border very slightly carinate.

Petiole and postpetiole as shown in Figs. 15 and 34. Petiolar node strikingly transverse without ridges or prominent posterodorsal laminule. Postpetiole even broader, with a pair of low diverging tubercles near entire posterior border, separated by a shallow median depression. Gaster anteriorly sharply marginate; tergum I without an antero-median impression and a distinct lateral margination.

Pilosity inconspicuous, minute and appressed, not scale-like; more visible on appendages and sharp ridges of body where they become decumbent.

Female and male unknown.

Distribution. - Although collected only twice, it is quite possible that vorticis is confined to the upper Amazon basin, in northwestern Brazil and northern Bolivia.

Specimens examined: 3 workers; besides the lone lectotype (NAW) already mentioned above, two more workers from Brazil, Rondonia territory, Sao Pedro, Rio Jamari, O.P. Forattini leg. on July 11, 1960 (WWK).

Discussion. - The Brazilian workers agree completely with the Bolivian type. Their measurements are the following: total length 3.6-3.9 mm; head length 0.83-0.88 mm; head width 0.78-0.83 mm; thorax length 1.20-1.31 mm; hind femur length 1.14-1.28 mm.

The closest ally of vorticis is salvini , differing the former from the latter in the following features: Body hairs simple, never scale-like; frontal lobes strikingly different in shape, broadly rounded cephalad, the curvature gradually decreasing caudad (cf. Figs. 1 and 3); the sigmoidal frontal carinae always fade out before reaching the spinelike occipital lobe; basal face of epinotum strongly and sharply carinate in its entire length; posterior mesonotal tubercles low, not tooth-like nor conical; petiole not noticeably constricted at each side just in front of postpetiolar insertion.

Nothing is known as regards the biology of vorticis .