Oxyepoecus myops, De Albuquerque & Brandão, 2009

Albuquerque, Nicolas Lavour de & Brandão, Carlos Roberto Ferreira, 2009, A revision of the Neotropical Solenopsidini ant genus OXYEPOECUS Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 2. Final. Key for species and revision of the Rastratus species-group, Papéis Avulsos de Zoologia 49 (23), pp. 289-309 : 295-297

Oxyepoecus myops n. sp.

( Figs. 1 a-c, 6)

Oxyepoecus myops n. sp. Albuquerque & Brandão. Holotype: worker. Brazil: São Paulo: Salesópolis [23°39’S, 45°53’W], 05-07.vii.1997, C.I. Yamamoto col., extracted from the leaf litter using Winkler extractor; deposited in MZSP.

Paratypes (all from Brazil): São Paulo : thirty workers and three gynes from Salesópolis (same locality of the Holotype, but collected in different dates and by different collectors), deposited in MZSP , one worker deposited in AMNH , one worker deposited in CASC , one worker deposited in CECL , one worker deposited in CPDC , one worker deposited in ICNC , one worker deposited in LACM , one worker deposited in MIZA , one worker deposited in USNM .

Etymology: The specific name refers to the relatively minute size of the compound eyes that characterize workers of this species.

Worker (Holotype and paratypes (N = 30), variation within brackets): t.l. = 2.08 (1.95-2,15); h.l. = 0.53 (0.50-0.53); h.w. = 0.40 (0.38-0.43); s.l. = 0.30 (0.28-0.31); m.l.e. = 0.06 (0.05-0.08); m.w.pr. = 0.25 (0.23-0.28); a.l. = 0.60 (0.58-0.60); h.f.l. = 0.33 (0.28-0.33); m.w.p. = 0.15 (0.13-0.18); m.w.pp. = 0.20 (0.18-0.20); c.i. 75 (76-81). Color chestnut brown, legs and antennae slightly lighter. Integument with irregularly reticulate sculpture covering almost all head dorsum, except close to clypeus, and around antennal insertions; almost all mesosoma, petiole dorsum and postpetiole with irregulary reticulate sculpture; gaster smooth and shining. Hairs relatively abundant, short, subdecumbent and curved mesad on head dorsum, and anteriorly curved on the head sides; long and suberect on dorsum of mesosoma, petiole and postpetiole; hairs on gaster decumbent and shorter.

Mandible with basal border approximately equal chewing border, basal tooth separated from subbasal tooth by shallow diastema. Anterior tooth of clypeus with lateral, blunt denticle. Frontal carinae short, subparallel, with posterior end at level of anterior margin of compound eye, maximum width between their outer edges less than one fourth of head width. Compound eye very small, with 3-4 facets r.g.d.; total number of ommatidia not exceeding 7. Antennal scape fails to reach vertexal margin by distance greater than maximum scape width. Funnicular segment I longer than either VIII or IX, as long as II-V combined, segments II-VII distinctly broader than long, VIII and IX as long as broad. Head with vertexal margin straight (f.f.v.).

Mesosoma with lateral and dorsal surfaces of pronotum not forming a well marked angle, slightly rounded. Metanotal groove weakly impressed (p.v.). Basal face of propodeum immarginate on sides, posteriorly with a small and obliquely directed tooth (p.v.). Declivous face laterally weakly carinate.

Petiole pedunculate, node scarcely compressed antero-posteriorly (d.v.); subpetiolar process with anterior end as a small and obliquely oriented denticle. Postpetiole strongly compressed antero-posteriorly, not as high as petiolar node; subpostpetiolar process shaped as small, transversal crest, parallel to ventrally produced posterior socket of postpetiole.

Gyne (variation of three paratype gynes): t.l. = (2.53-2.58); h.l. = (0.55-0.56); h.w. = (0.45-0.48); s.l. = (0.33-0.35); m.l.e. = (0.20-0.25); m.w.pr. = (0.43-0.45); a.l. = (0.70-0.73); h.f.l. = (0.38-0.40); m.w.p. = (0.18-0.20); m.w.pp. = (0.28-0.30); c.i. (81-86). Characters almost the same as workers, with the differences of the caste: the three ocelli with same diameter, approximately equal to minimum scape width, compound eye with 10 facets r.g.d., about 30 in all, scutellum not marginate.

Male: unknown.

Examined material: BRAZIL: Minas Gerais, Conceição do Mato Dentro, Serra da Serpentina, 18-28. iii.2009, Silva R.R. 067589/7894569 WGS 84 (1 S); Paraná: Tunas, Parque das Lauráceas, 21-29. ii.2001, [R.R.] Silva and [F.] Eberhardt cols., transecto 1 Winkler 16 [24°51’S, 48°43’W] (1 S); Rio de Janeiro: Santa Maria Madalena, P[arque] E[stadual] do Desengano, x.2002, Mayhé, A. & Veiga-Ferreira, S. cols., # 48 and # 17 [21°58’S, 41°57’W] (2 S); Nova Iguaçú, Re[serva] Bio[lógica] do Tinguá, ii.2002, Mayhé, A. & Veiga-Ferreira, S. cols., # 48 A10 [22°34’S, 43°24’W] (1 S); Teresópolis, P[arque] N[acional] da S[erra] dos O[rgãos], 23-27.xi.1999, Rocha [R.P.], Dietz [B.H.], Silva [R.R.] cols., # 03 [22°27’S, 42°59’W] (1 S); Santa Catarina: Blumenau, P[arque] E[stadual] das Nascentes, 20-27.x.2000, Silva, R.R. and Eberhardt, F. cols., [27°06’S, 49°09’W] (1 S); São Bonifácio, P[arque] E[stadual] Serra do Tabuleiro, 08-13.iii.2004, Silva, R.R.; Dietz, B.H. and Albuquerque, N.L. cols., [27°49’S, 48°54’W] (7 S, 1 T); Seara, v-xii.1998, Rogério R. Silva col. 24°07’S, 52°18’W (1 S); same locality, vi-vii.1999, same collector (7 S); São Paulo: Botucatu, 07.x.1987, Forti, L.C. and Rinaldi, I.M.P. cols [22°53’S, 48°26’W] (5 S – soil trap collected); Campos do Jordão, xi.1985, C.G. Froelich col. [22°44’S, 45°34’W] (2 S); Juquitiba, 30.x.1960, W.W. Kempf col. [23°56’S, 47°02’W] (1 S); São Paulo, P[arque] E[stadual] da Cantareira – Núcleo Engordador, 12-22.v.2003, R. Feitosa & A. Soliva cols. 23°21’S, 46°29’W (2 S); Salesópolis, 03-05.v.1996, Brandão [,C.R.F]; Agosti [,D.]; Diniz [,J.]; Silvestre, [,R.]; Yamamoto [,C.I.] [cols.] [23°39’S, 45°53’W] (4 S and 2 T); same locality, 02-06.v.1997, D. Agosti; C.R.F. Brandão; & C.I. Yamamoto cols (15 S); same locality, 05-07.vii.1997, C.I. Yamamoto col. (5 S); same locality, 05-07. ix.1997, C.I.Yamamoto, col. (4 S); Tapiraí, 08-14. i.2001, Silva, R.R. and Eberhardt, F. cols., [24°01’S, 47°27’W] (1 S) Cunha, P[arque] E[stadual] Serra do Mar (23°15’03”S, 45°00’26”W), 21-22.iv.2001, A. Tavares & R.R. Silva (samples # 5, 15, 28, 36, 38, 48, 50).(3 T and 8 S).

Comments: The exclusive character of Oxyepoecus myops n. sp. workers in relation to the other species of the Rastratus group is the irregularly reticulate sculpture fully covering the head dorsum and almost all the mesosoma dorsum. Their compound eyes are the smallest in the genus.

The distribution of O. myops n. sp. includes several Southern Brazil localities, and in Minas Gerais, São Paulo and Rio de Janeiro States. Workers of this species have been recently extracted from litter samples taken in localities at sea level and up to more than 1000 m high in the Serra do Mar Range. Most localities are covered by dense evergreen tropical forests, but in some cases, samples come from drier forests as well, as in Seara, SC and Teresópolis, RJ. In Serra da Cantareira, SP, workers were attracted to sardine baits set on the forest floor during the day.

Figures

FIGURE 1: Scanning electron micrograph of the workers of O. myops n. sp.; a) head in full-face view; b) mesosoma in profile view; c) Petiole and postpetiole in dorsal view.