Mycetophylax olitor

Kempf (1964) reported "There are no pertinent data, except for the fact that all collections of Mycetophylax olitor and Cyphomyrmex quebradae, its synonym, were made in mesophilous subtropical woods, in rather moist surroundings.

Identification
See the description below.

Distribution
The species, as presently defined, is known to occur in northwestern Argentine (Tucumán) and southeastern Brazil, from Rio Grande do Sul to Rio de Janeiro States.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Paraguay.

Nomenclature

 *  olitor. Cyphomyrmex olitor Forel, 1893e: 605 (w.q.) BRAZIL.
 * Wheeler, G.C. 1949: 670 (l.).
 * Combination in Atta (Cyphomyrmex), with unjustified emendation of spelling to olitrix: Forel, 1911c: 295.
 * Combination in Cyphomyrmex: Luederwaldt, 1918: 39.
 * Combination in Mycetophylax: Sosa-Calvo et al., 2017: 9.
 * Senior synonym of quebradae: Kempf, 1964d: 30.
 * quebradae. Cyphomyrmex quebradae Kusnezov, 1949d: 445, figs. 6-8, 11 (w.q.m.) ARGENTINA.
 * Junior synonym of olitor: Kempf, 1964d: 30.

Description
Kempf (1964) - The numerous specimens from southern Brazil, unfortunately all strays from berlesate collections, show an unusual range of variation. Only the lone workers from Petrópolis and Marambaia, Rio de Janeiro State, agree almost completely with the types. All others present a variable amount of discordant features. I have tried to separate the principal variants with the intention of discovering the existence of two or more so-called sibling species. But so far, all my attempts have been unsuccessful. Therefore I limit myself to an account of the chief variable characters for the worker caste.

1. Size: The types are near the lower end of the range. The largest specimen had the following measurements: Total length 3.5 mm; head length 0.85 mm; head width 0.77 mm; thorax length 1.09 mm; hind femora length 0.83 mm.

2. Head: Mandibular teeth 7-10, frontal lobes more often evenly rounded rather than rectangular; frontal carinae subparallel in the largest specimens; occipital lobes sometimes less distinctly set off in full face view.

3. Thorax: midpronotal tubercles strong to almost obsolete; lateral pronotal and both pairs of mesonotal tubercles usually lower than in types; mesoepinotal constriction variable; epinotal teeth either vestigial or well developed, with all kinds of intermediate conditions; hind femora moderately to conspicuously dilated and ventrally angulate at basal third, postero-ventral border always carinate, sometimes with a prominent foliaceous flange at angle.

4. Pedicel and gaster: lateral lobes of petiole, in ventral view, weakly to moderately longitudinally furrowed, the lateral border, especially on the posterior half carinate; in profile, the petiole is either completely depressed or shows an ascending anterior face distinct from a horizontal dorsal face (as in daguerrei), especially in larger specimens; in larger specimens the postero-dorsal transverse laminule forms sometimes a prominent semicircular apron; shape of postpetiole extremely variable in dorsal view, with all possible intergrades between extremes; lateral borders of tergum of postpetiole either completely appressed to sternum as in olitor types, or salient with more or less developed foliaceous margin; lateral borders of tergum I of gaster varying between sharply and indistinctly marginate.

As said before, I am reluctant to lump this variable array of forms under one species, but I cannot see another solution under the present circumstances. Later on, when good series from many colonies will be available, one might be tempted again to try for more satisfactory results.

Worker
Kempf (1964) - (lectotype) Total length 2.6 mm; head length 0.64 mm; head width 0.56 mm; thorax length 0.78 mm; hind femur length 0.59 mm. Yellowish brown, vertex of head more reddish brown. Integument opaque, densely and minutely granulate. Dorsum of head between frontal carinae and tergum I of gaster with small piligerous tubercles.

Head (fig 7). Mandibles finely reticulate-punctate and somewhat longitudinally rugulose; chewing border with 7-8 teeth, gradually diminishing in size towards base. Anterior clypeal border scarcely notched in the middle, laterally with a small tooth on each side. Frontal area distinct and impressed. Frontal lobes oblique, rectangular, moderately expanded laterad, not reaching in full-face view the preocular carinae, covering only in part the antennal scrobe; lateral borders somewhat diverging and sinuous, posterior prolongation of frontal carinae nearly straight and gently diverging caudad. Occipital corners slightly produced. Occiput broadly and shallowly excised, with another somewhat deeper excision in the middle between the short, but prominent carinae of vertex. Supraocular tumulus feeble and indistinct. Postero-inferior corner of head without a foliaceous carinule. Scapes in repose attaining but not surpassing the occipital corner. Funicular segments II-VII scarcely longer than broad.

Thorax (fig 19). The single midpronotal tubercle low, often indistinct: lateral teeth much more prominent; antero-inferior corner of pronotum forming a slightly protruding yet subrectangular tooth. Mesonotum flat to slightly excavate, with the costumary two pairs of tubercles, one tubercle to each corner; anterior tubercles in profile broadly rounded, tumuliform; posterior tubercles subconical with broadly rounded apex. Mesoepinotal constriction pronounced. Basal face of epinotum nearly as long as declivous face, with a pair of blunt tubercles at anterior border, another faintly marked pair posteriorly, marking the limit of the declivous face. Femora very lightly crested beneath. Hind femora only gently dilated at basal third, the postero-ventral crest not forming at this place a prominent foliaceous flange.

Pedicel (19, 33). Note the narrow postero-median laminule flanked by very faint longitudinal carinules. Lateral lobes solid, only shallowly excavated beneath. Postpetiole cupuliform, dorsally broadly impressed, the impression flanked by a low and blunt ridge which terminates posteriorly in a low, scarcely raised tubercle. Lateral lobes completely appressed to sternum, not excavated beneath nor foliaceous. Tergum I of gaster with a faint longitudinal furrow on anterior half, the lateral borders distinctly marginate, especially on anterior half.

Hairs on thorax and pedicel minute appressed, indistinct; head, gaster and appendages with small recurved and decumbent hairs.

Queen
Kempf (1964) - (paratypes) Total length 3.3-3.4 mm; head length 0.75-0.77 mm; head width 0.67-0.68 mm; thorax length 0.96-0.98 mm; hind femur length 0.72-0.75 mm. Ferruginous; decidedly darker than the workers of the type series. Head as in worker, including shape of frontal carinae, slightly protruding occipital lobes. Ocelly very small. Mandibles with 7-8 teeth. Pronotum laterally immarginate, with a strong conical tooth on each side. Midpronotal tooth absent. Antero-inferior corner of latero-tergite of pronotum with a prominent tooth. Scutum flat troughout; anteriorly with a pair of faint tumuli just inside the anterior extremity of the arms of the vestigial and scarcely impressed Mayrian furrows, Scutellum posteriorly distinctly bidentate, a semicircular excision separating the two teeth. Basal face of epinotum continuous with declivous face, i. e. dropping down steeply to petiolar insertion just behind the meta-epinotal suture. Epinotal teeth small, much as in nemei. All femora with the postero-ventral border marginate and finely carinulate; hind femora very gently thickened at basal third, without a projecting foliaceous flange. Postpetiole broader and stouter than in worker, with a deep and large dorsal impression, flanked by a pair of longitudinal and slightly carinulate welts; postero-lateral impressions also present; lateral lobes of tergum completely appressed to sternum. Tergum I of gaster covered with abundant piligerous tubercles, its anterior half carinate laterally, mesially with a shallow and rather indistinct longitudinal furrow. Wings unknown. Pilosity as in worker.

Male
Kempf (1964) - described by Kusnezov (1949) as the synonomized Cyphomyrmex quebradae.

Type Material
Kempf (1964) - 3 Workers (lectotype and paratypes) and 2 females (paratypes), collected by Dr. A. Moeller near Blumenau, Santa Catarina State, Brazil, received on loan from the Forel collection (MHNG). 6 workers and 1 female, syntypes of quebradae Kusnezov, received as a gift from Miguel Lillo Institute (WWK).

References based on Global Ant Biodiversity Informatics

 * 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 7: 1-44.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Wheeler G. C. 1949. The larvae of the fungus-growing ants. Am. Midl. Nat. 40: 664-689.
 * Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.