Cyphomyrmex lectus (Forel) Kempf, W. W., 1964

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 : 36-38

12. Cyphomyrmex lectus (Forel) nov. stat.

(Figs. 12, 14, 36, 55)

Atta (Cyphomyrmex) olitrix lecta Forel , 1911: 295 (Worker; Brazil, Sao Paulo City: Ipiranga).

Cyphomyrmex olitor lectus : Santschi, 1925: 164 (Argentina, Santa Fe: Fives Lille). - Luederwaldt, 1926: 267 (Bion.). - Weber, 1940: 410 (Key).

Cyphomyrmex olitor : Kusnezov, 1957: 9 (Key).

Types. - 14 workers taken by H. Luederwaldt in the borough of Ipiranga in Sao Paulo City, in 1909 (MHNG, DZSP, WWK).

Worker (lectotype and paratypes). - Total length 2.7- 2.8 mm; head length 0.64-0.67 mm; head width 0.59-0.61 mm; thorax length 0.80-0.83 mm; hind femur length 0.59-0.61 mm. Yellowish brown; front of head ferruginous; legs rather pale.

Head as shown in Fig. 12. Mandibles finely reticulatepunctate and vestigially striolate; chewing border with 7 teeth; apical tooth prominent. Anterior clypeal border slightly notched in the middle, laterally with a small tooth. Frontal area more or less distinct and impressed. Frontal lobes greatly expanded laterad, covering in full-face view part of the eyes, anteriorly rounded, then diverging caudad and somewhat sinuous, rounded behind before the gentle constriction; frontal carinae prolonged caudad, slightly diverging, joining the narrowly crested preocular carina to close the antennal scrobe at the scarcely drawn-out occipital corner. Occiput broadly but gently emarginate, with another median and deeper emargination between the short and inconspicuous carinae of the vertex. Supraocular tumulus feeble and indistinct. Inferior border of cheeks immarginate, except for a short and low foliaceous carina in front of the inferior occipital corner (Fig. 53). Scapes in repose not surpassing the occipital corner. Funicular segments II-VIII not longer than broad.

Thorax as shown in Fig. 14. Midpronotal tooth feeble and indistinct, lateral teeth low and subconical, anteroinferior corner with a very long tooth pointing foreward. Mesonotum flat to slightly excavate, flanked by the anterior and posterior pair of very low tubercles, which clearly separate the dorsum from the sides. Mesoepinotal suture distinct, but only gently impressed. Basal face of epinotum much shorter than the laterally immarginate declivous face, posteriorly unarmed. Inferior borders of femora faintly crested; hind femora gradually increasing in depth toward basal third, forming ventrally an angle, the posteroinferior border being armed at this place with a prominent foliaceous flange.

Pedicel as shown in Figs. 14 and 36. Note the narrow postero-median laminule flanked by short longitudinal carinules. Postpetiole cupuliform, dorsally flattened; lateral lobes with foliaceous margin, not appressed. Tergum I of gaster with marginate anterior border, laterally immarginate, mesially not impressed.

Integument densely granulate, opaque, with sparser small setigerous pits. Hairs minute, completely appressed. Gular face of head and sternum I of gaster with curved subdecumbent hairs.

Female and male unknown.

Distribution. - Aside from the type series, this species has also been recorded by Santschi (1925: 164) from Fives Lille, in Santa Fe Province, Argentina. I have not seen these specimens.

Discussion. - The broadly expanded frontal carinae, the foliaceous carina on posterc-inferior corner of head, the huge inferior pronotal spine, the unarmed epinotum, vouch for specific distinction from olitor . The species seems more closely related with nemei and perhaps vallensis .

Bionomics. - According to Luederwaldt (1926: 267) the nest cf this species was found in an open field (same habitat as Mycocepurus goeldii ). The cavities were subspherical. The fungus garden is sessile.

Note. - 1 have a few stray workers and a female from several widely separated localities, that are very close to lectus , but offer at the other hand several distinctive features, which make their association with lectus somewhat doubtful. I am not proposing, at this stage, a new name for these specimens, but limit myself to point out their diverging characters.

Workers. - Occipital lobes more prominent, usually a little set off. Frontal carinae somewhat less expanded, not covering part of the eye in full-face view. Inferior occipital corner without a foliaceous carina. Inferior pronotal tooth rectangular. Petiole broader, more constricted behind. Postpetiole usually broader, often dorsally impressed. In addition, in some specimens there is a tendency toward fading of the microsculpture, especially on sides of head and on the thorax.

The single female is quite close to that of nemei , differing principally in the complete lack of epinotal tubercles, narrower and longer postpetiole, and in the lack of a broad, deeply impressed longitudinal furrow on anterior half of tergum I of gaster.

The specimens came from the following localities: Argentina, Tucuman (N. Kusnezov) 1 worker (WWK). - Brazil, Mato Grosso State: Dourados (R. Mueller) 1 worker (WWK), Sao Paulo State: Agudos (R. Mueller) 1 worker (WWK), Para State: Capanema (C. R. Goncalves) 1 female (WWK). - Surinam: Lelydorp (Geijskes) 6 workers (WWK).

According to Kusnezov's description of the only known worker of nemei , the latter differs from the afore mentioned workers principally in the configuration of the mesonotum, which lacks the two pairs of tubercles, having the sides immarginate and the disc convex; the postpetiole much broader, similar to that of quebradae . We need more specimens to settle this problem.

The possible identity of these specimens with vallensis has already been mentioned on a foregoing page.