Mycetagroicus urbanus,

Brandão, C. R. F. & Mayhé-Nunes, A. J., 2001, A new fungus-growing ant genus, Mycetagroicus gen. nov. with the description of three new species and comments on the monophyly of the Attini (Hymenoptera: Formicidae)., Sociobiology 38, pp. 639-665: 657-661

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Mycetagroicus urbanus

new species

Mycetagroicus urbanus  HNS  new species

Figs 17-23

Holotype: Worker BRAZIL, Sao Paulo State: Sao Paulo [23° 32' S, 46° 37' W], [ Parque do) Ibirapuera , 10. x. 1943, C. R. Goncalves leg. [ # 482 on Goncalves' notebook], deposited at MZSPGoogleMaps  .

Paratypes: 6 workers, same data as holotype [3 MZSP- one prepared forSEM; 1 IBUS, 1 NMNII, 1 BMNH]  .

Etymology. We have chosen the Latin name urbanus because the only known sample ofthis species was collected at the main public park within Sao Paulo city.

Description. Worker. Measurements (in mm): TL 2.64; HL 0.91; HW 0.82; IFW 0.43: ScL 0.71; TrL 1.11; HfL 0.88. Color medium brown, gaster and frons darker. Short and scarce hairs all over the body, denser on appendages (Fig. 17-18).

Head (Figs 17, 20. 23). Dorsal surface of the mandibles (Fig. 20) not so strongly sculptured as in the other species (some 20 rugulae in a straight line perpendicular to the mandible, at midlength), fading but not ending in a straight line as in M. cerradensis  HNS  , each rugula blending with the superficial texture of the mandibles near the smooth flange at the masticatory margin. Masticatory margin of the mandible with an apical tooth and 6 sub-apical irregular teeth, the 3 apical ones rounded and more spaced, while the 3 basal ones are more prominent and closer to each other: outer border straight from the apical tooth level of the second basal tooth. Clypeus lateral regions near the base of frontal lobes without projections. Frontal area inconspicuous. Frontal lobes rounded, their largest width posterior to the antennal insertions. Frontal carinae slightly sinuous, fading well before reaching the occiput. Eyes with 10 facets across the greatest diameter. Antennal scapes surpassing the occipital margin by 1 /6 of its chord length when laid back over the head as much as possible. Only funicular segments I and VIII-X longer than broad, the other subequal to each other.

Alitrunk (Figs 18-19, 21). Lateral pronotal spines (Fig. 19) scarcely projecting from pronotal lateral margin, irregular in shape; pronotum with a pair of short but conspicuous median spines; antero-inferior corners angulated (Fig. 18). Mesonotum with a median projection as a relatively high conical protuberance, microscopically tuberculated. Metanotal groove relatively narrow and deeply impressed. Opening of propodeal spiracle almost rounded in side view.

Petiole, postpetiole and gaster (Figs 18, 21-22). Dorsum of petiole with two low longitudinal ridges; in lateral view, triangular and acute; the node proper, as seem from above, slightly broader than long. Postpetiole slightly longer than broad in dorsal view; the posterior margin projected above the level of the postpetiole dorsum, in lateral view (Fig. 18). Gaster hair pits as irregularly distributed as in M. triangularis  HNS  , without dorsal keels (Fig. 22).

Biology. At Cincinnato R. Goncalves' notebook we have found the following information: "# 482 - Mycetosoritis  HNS  . Attini em revoada [in dispersion flight;. Ibirapuera, Sao Paulo, SP. 10. x. 1943. C. R. Goncalves". He recorded the nest entrance as narrow and surrounded by a single low mound, made up of fine grains of earth. The fact that Goncalves collected these specimens while in dispersion flight suggests that he may have collected sexuals along with the workers we have found in the MZSP. Supporting this idea, we have found in Kempf's notes, records on males of an "unidentified attine genus", supposedly belonging to this sample. However, all attempts made to locate sexuals of this sample failed. Sexuals from this locality with the same label number were not found also at IBUS, where most of Golcalves material has been deposited.

Comments. Unlike M. cerradensis  HNS  and M. triangularis  HNS  , M. urbanus  HNS  does not have lateral clypeal teeth; M. urbanus  HNS  share with M. triangularis  HNS  the presence of two conspicuous median low irregular spines in the middle ofthe pronotum. Only the funicular segments I and VIII-X arc longer than broad, as in M. triangularis  HNS  , but the mesonotal protuberance is higher than in the other species. The M. urbanus  HNS  frontal lobes are rounded, with their largest width posterior to the antennal insertions The paratype worker in Figs 9-10 is a relatively aged worker, considering the material already accumulated over the integument; its mandibular teeth apices are very much worn out, suggesting that younger workers of M. urbanus  HNS  may have much more acute and long mandibular teeth.


Brazil, Sao Paulo, Sao Paulo, Museu de Zoologia da Universidade de Sao Paulo


Brazil, Rio de Janeiro, Seropedica (Itaguai), Universidade Federal do Rio de Janeiro


United Kingdom, London, The Natural History Museum [formerly British Museum (Natural History)]