Mycocepurus goeldii Forel

Kempf, W. W., 1963, A review of the ant genus Mycocepurus Forel, 1893 (Hymenoptera: Formicidae)., Studia Entomologica (N. S.) 6, pp. 417-432 : 420-425

Mycocepurus goeldii Forel

(Figs. 1-8)

Atta (Mycocepurus) goeldii Forel , 1893a: 370 nota (Worker; Brazil, S. Paulo: Botucatu). - Forel, 1908: 353-354 (Female, male; Brazil: S. Paulo City). - Forel, 1911: 293 (Brazil, Parana: Castro). - Luederwaldt, 1918: 39, 01, fig. (Fungus garden; Brazil, S. Paulo: lpiranga).

Mycocepurus goeldii : Luederwaldt, 1926: 266-267 (Bion.). - Menozzi, 1926: 68 (Brazil, S. Paulo: Mogi das Cruzes). - Santschi, 1933: 123. figs. 11, 14 (Worker). - Kerr, 1961: 46-48 (Bion.).

Atta (Mycocepurus) goeldii var. schuppi Forel , 1901: 301-302 (Worker; Brazil. Rio Grande do Sul: Porto Alegre). - NOV. SYN.

Mycetopurus goeldii gentilis Santschi , 1924: 17-18 (Worker; Brazil, Minas Gerais: Pirapora). _ NOV. SYN.

Mycocepurus goeldii gentilis Santschi , 1933: 123, fig. 10 (Worker).

Mycocepurus ogloblini Santschi , 1933: 119-120, figs. 7, 8, 12,-13 (Worker, female; Argentina. Misiones: Est. Loreto). - Kusnezov, 1956: 48, fig. 70 (Male). - NOV. SYN.

Descolemyrma ogloblini Kusnezov , 1951: 460-461, 1 fig., 1 pl. (Male; Argentina, Misiones: Est. Loreto).

Worker. - Total length 3.0-4.0 mm; head length 0.72- 0.96 mm; head width 0.72-0.93 mm; scape length 0.59-0.85 mm; thorax length 0.91-1.20 mm; hind femur length 0.69-0.99 mm. Integument densely punctate, fine reticulation indistinct.

Head as shown in Fig. 1, rather squarish and broad with bulging cheeks. Occipital angles obliquely truncate and denticulate. Frontal carinae more or less distinct on posterior half of head, almost reaching the occipital border. Occiput in side-view perpendicular to dorsum of head, forming an obtuse but distinct angle with gular face. Mandibles relatively broad; chewing border with 6 teeth or, if only 5, there is a noticeable diastema between the first and second basal teeth, occasionally showing a rudimentary denticle. Base of antennal scape dilated into a prominent ringlike lamina.

Thorax and pedicel as shown in Figs. 2 and 3. Premesonotal disc with a circlet of 6 well-developed pairs of teeth or spines, one pair occupying the center of the circlet. Anterior pair of posterior mesonotal spines prominent. Petiole compact, with a short peduncle; node bearing on each side a transverse carinule and on top four conspicuous spines, the anterior pair separated from the posterior pair by a deep excision. Postpetiole relatively deep, lacking a pronounced median furrow on disc.

Erect or suberect hairs on scape, clypeus, dorsum of head, dorsum of postpetiole and gaster, and on extensor face of tibiae.

Female. - The specific characters for this caste are practically the same as for the worker, although some of them may lack an equally distinct expression. The most striking feature is the relatively large size: Total length 5.3-6.0 mm; head length 1.01-1.09 mm; head width 0.98-1.07 mm; scape length 0.80-0.91 mm; thorax length 1.55-1.71 mm. The mandibles present almost always 6 teeth, rarely 5. Pronotum laterally with two welldeveloped scapular spines. Vermiculate-rugose sculpture coarse on head, thorax, dorsum of postpetiole and on gaster. Pilosity as in worker. Wings as described for male below.

Male. - Total length 5.6-6.2 mm; head length 0.83-0.96 mm; head width 1.01-1.15 (including eyes); scape length 0.69- 0.80 mm; thorax length 1.73-1.94 mm. Black; funiculus and tarsi fuscous-brown. Integument reticulate-punctate, opaque. Head as shown in Fig. 4. Occipital angles conspicuously dentate. Funicular segments II-XI at least four times as long as broad. Pronotum with two scapular teeth on each side. Mesonotal scutum and scutellum with longitudinal and spaced costae; rest of thorax more or less completely costate-rugose. Epinotal spines acute. Petiolar node antero-dorsally with or without a pair of small teeth. First gastric tergum about as broad as long. Pedicel and gaster with long, oblique to subappressed hairs. Genitalia as shown in Figs. 7 and 8. Wings (Figs. 5, 6) infuscated, venation as described in generic diagnosis.

Distribution. - M. goeldii is known to occur from Santa Fe in the Argentine north to the Amazon river. The westernmost records are of Corumba, Mato Grosso State and Manaus, Amazonas State, both in Brazil.

Specimens examined. - Several hundred individuals comprehending representatives of all three castes, as follows; Worker. - Argentina, Santa Fe: Nare (N. Kusnezov); Misiones: Est. Loreto (A. A. Oglobiin) (CTB, MCZ). - Brazil, Rio Grande do Sul: Pareci Novo (B. Rambo, S.J.) (CTB); Santa Catarina: Chapeco (L. Stock, O.F.M.) (CTB), Nova Teutonia (F. Plaumann); Parana: Castro (E. Garbe) (CTB, DZSP); Sao Paulo: Agudos (C. Gilbert, O.F.M., W. W. Kempf, O.F.M., R. Mueller, O.F.M.), Barueri (K. Lenko), Conchas (W. W. Kempf), Guaratingueta (L. Wzorek, O.F.M., W. W. Kempi), Jacarei (S. B. Pessoa) (CTB), Mogi-Mirim (K. Lenko), Pedreiras (Schwebel) (CTB), Ribeirao Preto (O. Conde) (CTB), Rio Claro (T. Borgmeier, W. E. Kerr) (CTB, WWK), Sao Paulo (H. Luederwaldt, W. W. Kempf) (CTB, DZSP, WWK), Sorocaba(F. Grossmann) (DZSP); Rio de Janeiro: Itatiaia (T. Borgmeier, O.F.M., C. R. Gomjalves, W. C. Zikan) (CTB, DDSV), Niteroi (T. Borgmeier) (CTB), Rezende (C. R. Gon-?alves) (CTB); Minas Gerais: Carmo da Cachoeira (E. V. Bretas), Januaria (C. R. Gon<;aIves) (DDSV), Monlevade (E. Luja) (CTB), Paraopeba (R. de Souza) (CTB), Pirapora (E. Garbe) syntypes of M. goeldii gentilis Sa. (MCZ), Mons. Paulo (V. dos Santos), Tres Coracoes (E. Araujo), Varginha (T. Borgmeier, M. Alvarenga & C. A. C. Seabra) (CTB^ WWK); Goias: Anapolis (W. W. Kempf), Catalao (W. W. Kempf); Mato Grosso: Campo Grande (K. Lenko) (DZSP), Chapada (C. Amann, 0. F.M.), Corumba (C. R. Goncalves) (CTB, DDSV), Jardim (R. Mueller), Rondonopolis (C. Gilbert); Para: Belterra (C. R. Goncalves) (DDSV, CTB), Obidos (C. R. Goncalves) (CTB, DDSV), Santarem (C. R. Goncalves) (CTB, DDSV); Amazonas: Manaus (C. R. Goncalves, K. Lenko) (CTB, DDSV). - Females. - Argentina, Misiones: Est. Loreto (A. A. Ogloblin) (MCZ). - Brazil, Rio Grande do Sul: Pareci Novo (B. Rambo) (CTB); Santa Catarina: Chapeco (L. Stock) (CTB), Nova Teutonia (F. Plaumann); Sao Paulo: Agudos (C. Gilbert, W. W. Kempf), Rio Claro (W. E. Kerr), Sao Jose do's Campos (H. S. Lopes) (CTB), Sao Paulo (Luederwaldt) (CTB, DZSP); Rio de Janeiro: Itatiaia (W. C. Zikan) (CTB); Minas Gerais: Carmo da Cachoeira (E. V. Bretas), Paraopeba (R. de Souza) (CTB); Goias: Leopoldo'Bulhoes (R. Spitz) (CTB). - Males. - Brazil, Santa Catarina: Chapeco (L. Stock). (CTB), Nova Teutonia (F. Plaumann); Parana: Castro (E. Garbe) (CTB); Sao Paulo: Agudos (W. W. Kempf, C. Gilbert), Juquia (J. Lane) (CTB), Rio Claro (W. E. Kerr), Sao Paulo (Luederwaldt, J. N. Pupo Nogueira) (CTB, DZSP); Minas Gerais: Monlevade (E. Luja) (CTB); Goias: Leopoldo Bulhoes (R. Spitz) (CTB); Mato Grosso: Corumba (C. R. Goncalves) (CTB). - (All specimens in WWK unless noted otherwise).

Synonymy. - Following is a brief characterization of each form presently placed into synonymy of goeldii , with a justification for the step taken.

1. M. goeldii var. schuppi Forel , 1901, worker. - Types not seen. In the description they are said to differ from the typical goeldii in the stronger tuberculate sculpture principally on head and legs, in the lighter color and the slightly narrower head. According to the aforesaid characters the variety falls well within the normal range of variation of goeldii and does not deserve to be named.

2. M. goeldii gentilis Santschi , 1924, worker. - Two syntypes '(MCZ) examined. These specimens stand out by the strongly developed spinulation on head, thorax and pedicel. The rather narrow and short petiole possesses antero-dorsally a pair of teeth that separate in side-view the anterior from the dorsal face. However, in all other respects these workers exhibit the essential features of goeldii and do not constitute a geographical race. Closest specimens in my collection hail from Obidos, Para State and Catalao, Goias State, Brazil. The latter are also otherwise outstanding by the extreme development of the upright pilosity.

3. M. ogloblini Santschi , 1933, worker and female. - The worker is characterized by a less rugose head, with frontal carinae rather obsolescent posteriorly, by the mesonotal spines which exceed in length the median pronotal spines, by more depressed postpetiole (Santschi says: petiole!) having the longitudinal carinae better developed than in the typical goeldii . No differential diagnosis is given for the female. Examination of three topotype workers and one female prove at once that this is a straight synonym of goeldii . The preceding characters do not exceed the variation found often in single nest series.

4. Descolemyrma ogloblini Kusnezov , 1951, male. - The types originate from the same locality as M. ogloblini Santschi and doubtless represent the male sex of the latter. Kusnezov (1956) tacitly recognized his mistake by dropping altogether Descolemyrma in his key to the Argentine ant genera and reproducing the figures of Descolemyrma under the heading of Mycocepurus ogloblini Santschi . Although I was unable to see the types, the description seems to me sufficiently detailed to show that this is the male of M. goeldii . As regards the special emphasis given by Kusnezov to small deviations in the wing venation, it is well to remember that Emery in 1922 already pointed out that the venation in this genus is quite inconstant. Since to my knowledge no formal synonymy has as yet been published for the present form, it is done so at this place.

Bionomics. - Luederwaldt (1918, 1926) is the only student who observed more closely the habits of the present species. Following is a summary of his findings:

M. goeldii is quite common in the fields in the Sao Paulo City area. The workers forage on the ground - they never climb up on plants - and have been seen collecting flowers of Schinus terebinthifolius and Bacharis dracunculifonia, seeds of Bidens pilosus, and caterpillar droppings. The booty is taken back to the nest or deposited on the outside round the entrance. The tiny ants are very timid, feigning dead when disturbed. While foraging, they are often attacked by other ants, especially by Pheidole spp.

The nest chambers are found in the soil at depths varying between 30 and 120 cm, and consist in round cavities of approximately 10 cm in diameter. The walls look polished and sometimes are lined with the dark feces of the ants.

The fungus-garden bears a peculiar aspect, consisting of narrow and elongate strips, 1.5-4.5 cm in length and 1.5 cm in width, suspended from the ceiling of the cavity like clothes hung up in a closet. The strips are yellowish-brown in color and are made up of tiny bits of plant material woven together by the mycelium of the fungus. Often, in nearby holes, stores of larger pieces of plant material are found piled up in heaps, perhaps to allow for fermentation before being used as substratum for the fungus-culture. Refuse is constantly being removed from the nest and deposited near the entrance.

Generally, there is only a single entrance to each nest, but this number may be increased considerably during the mating season. Luederwaldt counted once a maximum of 21 openings to a single nest. In the dry season, the workers build around the orifice of the entrance mounds of loosely piled up earth crumbs, which are either washed away by the first rain, or cimented together as craters.

The colonies are relatively small and the maximum number of workers to a nest probably does not exceed several hundreds. Nuptial flight takes place at clay-time from October to February, the actual mating of both sexes is accomplished sitting on leaves. Occasionally only males or only females seem to swarm at a given locality. After the mating season is over, the workers resume their regular foraging activity Further details on the nuptial flight of the species are contained in Kerr's (1961) recent contribution.

According to my own observation at Agudos, Sao Paulo State, where goeldii is exceedingly common, the mating season occurs early in spring after the first warm rain, principally during the month of October. The outward appearance of the nest site, the structure of the mounds and craters, the collecting of flowers and seeds seem to be constant for the species, according to my field experience in Sao Paulo and Goias States.