Cyphomyrmex paniscus Wheeler

Kempf, W. W., 1964, A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part I. Group of strigatus Mayr (Hym., Formicidae)., Studia Entomologica (N. S.) 7, pp. 1-44 : 18-20

4. Cyphomyrmex paniscus Wheeler

(Figs. 3, 20, 28, 49)

Cyphomyrmex paniscus Wheeler , 1925: 42-44 (Worker, female, male; Brazil).

Types. - 3 workers and 3 alate females (MCZ), collected by Hj. Mosen in Brazil (locality not given), examined.

Worker (lectotype). - Total length 4.5 mm; head length 1.07 mm; head width 0.98 mm; thorax length 1.36 mm; hind femur length 1.25 mm. Light reddish brown. Integument opaque and finely granular, including the antennal scrobe.

Head as shown in Fig. 3. Mandibles finely striolate-punctate, chewing border serially dentate with (7-) 9 teeth. Clypeus: anterior border mesially excised, middle portion obliquely raised toward front, with two prominent lateral and widely separated blunt teeth next to the origin of frontal lobes. Two pairs of longitudinal carinules on dorsum of head, one extremely feeblejust behind the deeply impressed frontal area, the other strong, more widely spaced and posteriorly slightly converging on vertex. Frontal carinae behind moderately expanded frontal lobes scarcely sinuous and slightly diverging. Supraocular tooth conical and prominent, not connected by a low ridge with inferior occipital corner. Inferior or outer border of antennal scrobe only vestigially carinate and somewhat indistinct between eyes and occipital lobes. The latter (Fig. 49) prominent, rounded, not longer than their maximum width. Lower border of sides of head bluntly marginate but not carinate. Antennal scape in repose slightly projecting beyond tip of occipital lobe. All funicular segments distinctly longer than broad.

Thorax as shown in Fig. 20; slender. Pronotum: anterior and lateral border of dorsal face marginate and carinate; a single prominent conical median tubercle on disc; lateral tubercles likewise prominent, blunt, projecting obliquely sidewards; anteroinferior corner of laterotergite with a small, acute tooth. Mesonotum: two pairs of prominent tubercles, anterior pair with elongate, laterally compressed base, triangular in profile, posterior, pair of subequal height, subconical. A deep and broad impression between posterior pair of mesonotal teeth and the anterior end of the widely spaced and feeble longitudinal carinules of basal face of epinotum which terminate behind in a small, rectangular tooth (sometimes indistinct). Legs relatively long and slender, hind femora weakly dilated and vestigially carinate on posteroinferior border at basal third.

Pedicel as shown in Figs. 20 and 28. Petiole broader than long, anterior corners in dorsal view narrowly rounded, anterior face oblique, terminating in front of small paired dorsal tubercles. A shallow median impression between these tubercles. Postpetiole broader than long, compact, much broader than petiole, with a long raised perpendicular anterior face; dorsal face quadrituberculate, pairs of each side connected by a faint longitudinal, blunt and posteriorly diverging ridge, area between ridges, and laterad of posterior tubercles shallowly excavate, posterior border of postpetiole between posterior tubercles slightly emarginata Tergum 1 of gaster laterally marginate and subcarinate. Instead of a median pair of carinae there is a faint, longitudinal, median impression on anterior half.

Small, fine, glittering and scattered hairs on body and appendages appressed; more conspicuous and denser on scapes and legs.

Female (paratypes). - Total length 5.2 mm; head length 1.12-1.15 mm; head width 1.04-1.07 mm; thorax length 1.60 mm; hind femur length 1.39-1.44. Similar to the worker, with the usual differences of the caste. Differs from auritus , as follows:

Head differences as stated below for worker. In addition, the anterior half of middle portion of clypeus is not quite perpendicular to, but rather continuous with, the posterior portion, wedged in between frontal lobes. Inferior head border only bluntly carinate. Midpronotal tooth small, lateral pronotal teeth welldeveloped and conspicuously projecting laterad. Mesonotum quite resembling, but welts, ridges and furrows not so strong. Scutellum lacking a distinct tumulus in front of the shorter apically blunt posterior teeth. Excision between the same teeth shallower. Epinotal spines fingerlike with the tips curved inwards. Petiole distinctly broader than long and narrower in the rear than in front. Postpetiole exactly as in worker, the sides scarcely convex and not conspicuously diverging caudad, dorsal longitudinal ridges blunt, but stronger than in worker. Gaster only laterally and weakly carinate on tergum 1 which bears in the middle a deeply impressed hairless longitudinal furrow, reaching beyond half. Rest of gaster finely tuberculata. Wings infumated, dull reddish-brown with slightly darker veins.

Male described by Wheeler (1925). No specimens seen.

Discussion. - The present species is known only from the type- series. In over-all similarity C. auritus seems to be the closest relative. The worker of paniscus differs from the former in the following characters: 1. Head broader, occipital lobes shorter and rounded both in dorsal and lateral view, not horn-like; supraocular tubercle lacking the connecting ridge with inferior occipital corner; scape projecting beyond the tip of occipital lobes. Inferior border not carinate. 2. Thorax: lateral and median pronotal tubercles higher; mesonotal tubercles subequal in height, anterior pair laterally compressed and triangular in profile; ridges on basal face of epinotum weak and more widely spaced. 3. Pedicelar segments broader than long. Petiole with anterior corners rounded; postpetiole with the connecting ridge between anterior and posterior tubercles blunt and low. 4. Gaster lacking the median pair of longitudinal costae on tergum 1, having instead a faint longitudinal impression.

Wheeler's description is very good and detailed, with the exception of the following details: 1. His measurements are too low, due to a single linear-spread measuring. 2. The statement referring to a deep promesonotal constriction is a lapsus, should be mesoepinotal constriction. 3. 1 am at odds with the 3 pits mentioned for the petiole. At any rate, the types have no paired anterior pits on node; the posterior unpaired pit is the impression between the dorsal tubercles.

Variation. - The lectotype worker is the tallest. The smallest of the three measures as follows: Total length 4.1 mm; head length 1.01 mm; head width 0.93 mm; thorax length 1.23 mm; hind femur length 1.20 mm.

Note. - Unfortunately, the exact origin of the specimens is unknown. Among other captures by Hj. Mosen in Brazil, Wheeler cites Acromyrmex disciger Mayr , a typical denizen of southeastern Brazil. Hence it is quite probable that peniscus came from this region, the habitat of its closest relatives.