Mycetophylax conformis ( Mayr, 1884 )

Klingenberg, Christiana & Brandão, Roberto F., 2009, Revision of the fungus-growing ant genera Mycetophylax Emery and Paramycetophylax Kusnezov rev. stat., and description of Kalathomyrmex n. gen. (Formicidae: Myrmicinae: Attini), Zootaxa 2052 (1), pp. 1-31 : 7-17

Mycetophylax conformis ( Mayr, 1884)

( Figs. 1 , 6 a, b, 7 a)

Cyphomyrmex conformis Mayr, 1884: 38 ; (worker) Holotype, French Guiana, Cayenne (NHMW, not examined); Kempf, 1962: 34 (combination in Mycetophylax ); Kempf, 1972: 145 (catalogue); Jaffé, 1993: 183 (biology), Bolton, 1995: 268 (catalogue).

Myrmicocrypta brittoni Wheeler, 1907: 728 (worker) Syntype, " Porto Rico (sic), Santurce (Wheeler), no coll. date" (AMNH, examined); Wheeler, 1911: 170 (male); Cyphomyrmex (Mycetophylax) brittoni Emery, 1913: 251 ; Santschi, 1922: 355 (key); Kempf, 1962: 34 (synonym of Mycetophylax conformis ).

Mycetophylax brittoni var. littoralis Weber, 1937: 401 (worker) Syntype, " Trinidad, B. W. I. Mayaro Bay, 11.iii.1935, N. A. Weber" (MZSP, examined); Kempf, 1962: 34 (synonym of Mycetophylax conformis ); Klingenberg & Brandão, 2005: 45 (syntype worker in MZSP).

Worker ( Figs. 1 a, b, g and 7 a). Range of measurements (in mm) and indices of examined specimens (N = 80): IOD 0.58–0.78; HL 0.63–0.82; CI 91–101; SL 0.49–0.70; SI 76–98; ML 0.28–0.43; MI 39–59; WL 0.78–1.13; PrW 0.37–0.58; PL 0.10–0.20; PPL 0.17–0.29; GL 0.53–0.78; FL 0.64–0.92; TL 2.62–3.41.

Color dark brown to black, legs brownish. Entire body covered by short golden hairs, sparse and appressed. Legs and antennae covered by the same type of hairs, only the area between the preocular carinae and frontal carinae hairless, and masticatory border of mandibles with longer hairs. Sculpture shiny and areolate; mandibles shining.

Head slightly longer than wide (see CI). Compound eyes at anterior fourth of head with eleven ommatidia at major length and nine ommatidia at major width. Mandibles triangular with nine to ten regular teeth. Median portion of clypeus attaining posterior level of antennal insertions, ending in a rounded suture followed by a small but distinctly impressed hairless frontal triangle. External margins of frontal lobes gently rounded, their maximum expansion little more than half the distance between the median line and external borders of the head. Lateral carinae parallel to the head lateral margin in frontal view, touching the internal margins of the compound eyes, but not reaching the vertexal margin. The space between the lateral and frontal carinae depressed, mostly smooth or vestigially areolate. Antennal scapes slightly curved, surpassing the posterolateral corners of the head by a distance smaller than their diameter at apex. Antennae ending in a twosegmented club, last antennal segment as long as the two anterior together.

Mesosoma. In lateral view, profile of dorsal surface evenly convex and continuous, with a low vestigial tumulus at mid mesonotum. Inferior margin of pronotum mostly rounded, sometimes with a recognizable inferior spine, varying in size among individuals. Metapropodeal impression barely distinct. Basal face of propodeum slightly convex and armed with a pair of small but conspicuous spines, directed up-and backwards. Declivous face of propodeum concave and nearly with the same length as the basal face. Propodeal spiracle distinct, with rounded opening obliquely directed circa 30° in relation of the main body axis. Node of petiole twice as wide as the peduncle and, in lateral view, as long as high; postpetiole wider than long. Posterior area of postpetiole with a slight impression, however the posterior margin straight. Gaster with a small median ventral keel at first sternite.

Gyne (undescribed) ( Figs. 1 c, d, h, 6 a and 7 a)

Range of measurements (in mm) and indices of examined specimens (N = 10): IOD 0.82–0.96; HL 0.84–0.95; CI 96–102; SL 0.66–0.78; SI 77–87; ML 0.36–0.50; MI 36–46; WL 1.28–1.46; PL 0.22–0.30; PPL 0.22–0.26; GL 1.06–1.24; TL 4.00–4.65.

Color yellowish to brown, depending on age. Compound eyes at maximum length with 18 ommatidia and at maximum width with 17 ommatidia. In lateral view, scutum covering almost the whole pronotum, scutum flattened above. Pronotum with blunt and triangular inferior pronotal spines. Parapsidial lines smooth, shiny and free of hairs, almost parallel in relation to the median axis of the body. Notaulices almost indistinct, marked only by the lighter color of the integument; axillae subtriangular. Scutum-scutellar sulcus distinct and prescutellum well developed with longitudinal rugae. Scutellum reduced in width posteriorly; posterior margin slightly concave with two small protuberances at the posterior angles. Anepisternum subtriangular, anterior border of katepisternum sinuous; both divided by a groove. The propodeum with a pair of blunt spines, directed back- and upwards.

Male ( Figs. 1 e, f, i, 6 b and 7 a)

Range of measurements (in mm) and indices of examined specimens (N = 13): IOD 0.46–0.52; HL 0.46–0.53; CI 90–104; SL 0.44–0.52; SI 92–108; ML 0.18–0.22; MI 36–46; WL 1.02–1.18; PL 0.20–0.22; PPL 0.16–0.19; GL 0.82–0.94; TL 2.87–3.16.

Color brown. Mandibles, legs, base and apical segments of antennae yellowish. Integument areolateimbricate, gaster imbricate. Head subquadrate, posterolateral corners rounded, vertexal margin straight. Compound eyes with 25 ommatidia at maximum length and 20 ommatidia at maximum width. Number of teeth on mandibles variable, at most seven. The two subequal apical teeth longer than the preceding. Anterior clypeal margin straight, bearing three fine and long setae. Median portion of clypeus attaining the posterior level of antennal insertions. Posterior clypeal margin rounded. Frontal lobes reduced, not fully covering the antennal insertions, but attaining the posterior level of compound eyes. Lateral carinae following the compound eyes margin until its posterior level, then curving in direction of the middle of the head, converging to the posterior portion of the frontal lobes, and thus forming a rounded almost indistinct arch. Apex of antennal scapes a little wider than base. Antennae 12-segmented, ending in a three-segmented club; the last segment with the same length as the two anterior together. In lateral view, scutum covering more than 2/3 of the pronotum. Anterior pronotal spines vestigial. Notaulices shallowly impressed. Prescutellum reduced, triangular axillae small; scutum-scutellar sulcus distinct and impressed. Scutum subtriangular, with the anterior margin straight. Anepisternum subtriangular with the posterior vertex rounded; antero-inferior corner of katepisternum rounded. Propodeum with a pair of very small spines or teeth.

Examined material: BRAZIL: Bahia: Mangue Seco , 31.xii.1999 (C. Klingenberg), 3 w ( MZSP) ; Caravelas , 5.x.1993 (B. H. Dietz) 3 w ( MZSP) ; Pará: Salinópolis , 13–19.xi.1953 (C. R. Gonçalves) 4 w ( MZSP) ; Rio de Janeiro: Muriqui , 3–8.ii.2002 (C. Klingenberg & D. Couto-Lima) 6 w ( MZSP) ; Cabo Frio, Praia das Dunas , 3–8.ii.2002 (C. Klingenberg & D. Couto-Lima) 53 w, 15 q, 17 m ( MZSP, SMNK) ; Maricá, Barra da Maricá , 3–8.ii.2002 (C. Klingenberg & D. Couto-Lima), 48 w, 4 q, 7 m ( MZSP) ; Macaé , 3.v.1970 (W. W. Kempf) 6 w ( MZSP) ; São Paulo: Caraguatatuba v–vi.1962 ( Exp. Dept. Zool .), 20 w ( MZSP) ; no coll. data, 1 w ( MCSN) [C. Emery collection] ; PUERTO RICO: Tortuguera Camp, x.1950 (W. F. Buren) 17 w ( AMNH), 12 w ( USNM), 20.ix, 27.x.1950, (W. F. Buren) 17 w ( MZSP) ; Santurce , no coll. data (W. M. Wheeler) 28 w ( AMNH) ; TRINIDAD: Mayaro Bay , no coll. data (N. A. Weber) 1 w (Syntype) ( MZSP) ; VENEZUELA: Miranda: Higuerote , xii.1983 (K. Jaffé) 4 w, 1 q ( MZSP) .

Comments. Mycetophylax conformis is the type species of Mycetophylax . The species was first described by Mayr in 1884 as a member of Cyphomyrmex . Later Wheeler (1907) described Myrmicocrypta brittoni , which was synonymized with M. conformis by Kempf (1962), with whom we agree. Wheeler's description is rather complete; he suggested the species might belong to a different genus, that should also include M. emeryi described by Forel (1907), recognizing that these species actually do not fit in any other described Attini genus. The morphological character traits that define M. conformis are very similar accross the known distribution of the species, which has been much improved by recent collections. Only the size of the anteroinferior spines and propodeal spines varies. In the state of Rio de Janeiro, Brazil, alates were collected year round.

In 1962 Kempf redescribed M. conformis , comparing it with Cyphomyrmex morschi . He highlighted the differences between the species and challenged the validity of the genus Mycetophylax , taking into account the striking similarity between M. conformis and C. morschi .

Mycetophylax conformis occurs sympatrically with M. morschi in São Paulo and Rio de Janeiro Atlantic beaches, but their nest distribution does not overlap, as M. conformis nests close to the sea, at the pre-dunes, while M. morschi nests at the dune and “restingas” areas. Klingenberg et al. (2007) published detailed information on M. conformis nest architecture, position and size of the fungus chamber, composition of the waste, and colony population.

Figures

FIGURE 1. AutoMontage © images of Mycetophylax conformis from Brasil, Rio de Janeiro, Cabo Frio, Praia das Dunas: a, b, g) worker in lateral, dorsal and frontal view; c, d, h) gyne in lateral, dorsal and frontal view; e, f, i) male in lateral, dorsal and frontal view.

FIGURE 6. SEM images: a, b) Mycetophylax. conformis, gyne and male from Brasil, Rio de Janeiro, Maricá, Barra da Maricá, mesosoma in dorsal view; c, d) M. morschi, gyne and male from Brasil, Santa Catarina: Florianópolis, Praia da Joaquina, mesosoma in dorsal view, e, f) M. simplex, gyne and male from Brasil, Santa Catarina: Florianópolis, Praia da Joaquina, mesosoma in dorsal view; g) M. morschi, worker from Brasil, Santa Catarina: Florianópolis, Praia da Joaquina, head in frontal view, note single seta coming out of each pore; h) Kalathomyrmex emeryi, worker from Brasil: Amazonas: Manaus, Praia de Tupé (Rio Negro), anterior portion of head; i) K. emeryi, male from Brasil, Piaui: Canto do Buriti, saw-like mandibular teeth.

FIGURE 7. Distribution maps of the species a) Mycetophylax, with a detailed map of the distribution of M. morschi and M. simplex at the isle of Florianopolis b) Kalathomyrmex and c) Paramycetophylax.