Sericomyrmex scrobifer Forel, 1911

Jesovnik, Ana & Schultz, Ted R., 2017, Revision of the fungus-farming ant genus Sericomyrmex Mayr (Hymenoptera, Formicidae, Myrmicinae), ZooKeys 670, pp. 1-109 : 91-93

Sericomyrmex scrobifer Forel, 1911 Figures 61, 62(Worker); Figure 35 (Map)

Sericomyrmex scrobifer Forel, 1911: 296. Lectotype worker (here designated): BRAZIL, São Paulo,Ypiranga, [-23.5, -46.6], ANTC35980, Luederwaldt (NHMB, 1w, CASENT0912518). Paralectotypes: same data as lectotype (MHNG: 3w, USNMENT00445578).

S. scrobifer worker diagnosis.

Medium-sized species; mandible dorsally smooth and glossy; frontal lobe robust, wide, trapeziform to rectangular; frontal carina strongly developed; eye large, convex, protruding laterally in full-face view, lateral mesonotal tubercles sharp, first gastral tergite with both lateral and dorsal carinae strongly developed.

S. scrobifer worker description.

Measurements in mm, range (lectotype): HWe 0.83-1.12 (1) HW 0.78-1.05 (NA) HW1 0.83-1.13 (1.03) HW2 0.88-1.2 (1.1) HW 3 0.55-0.85 (0.7) IFW1 0.66-0.84 (0.78) IFW2 0.22-0.32 (0.22) HL1 0.8-1.1 (1) HL2 0.7-0.98 (0.9) SL 0.62-0.78 (0.68) EL 0.15-0.24 (0.17) Om 10-14 (13) WL 1.12-1.4 (1.25) PL 0.24-0.38 (0.24) PPL 0.2-0.28 (0.25) GL 0.74-1.68 (0.95) HFL 0.93-1.26 (1.07) PW 0.63-0.8 (0.7) CI 97-111 (100) FLI 72-83 (78) SI 62-77 (68) OI 16-23 (17) CEI 8-15 (10) [N=31]

Pilosity. Pubescence dense, often lighter than integument, appressed to decumbent. Setae often curved, darker in color at base, appressed to suberect, mostly decumbent.

Head. In full-face view slightly broader than long (CI=104 ± 3), posterior corner angular to acute. Lateral margin of head straight to slightly convex, posterior cephalic emargination distinct, relatively deep (CEI=11 ± 1), gradually impressed. Vertexal impression usually distinct, frontal tumuli faint. Mandible with 7-8 teeth, dorsally smooth and glossy, finely transversely striate only along masticatory margin. Eye large (OI=20 ± 2), distinctly convex, protruding from sides of head in full-face view, without white layer, 10-14 ommatidia across largest diameter. Frontal lobe wide (FLI=76 ± 3), laterally expanded, trapeziform to rectangular, posterior margin as long as medial, slightly shorter in some specimens, lateral margin sometimes mildly concave and serrate (Figure 61b). Frontal carina robust, complete, straight to slightly curved laterally. Antennal scape relatively short, not reaching posterior cephalic corner (SI=70 ± 3).

Mesosoma. Lateral mesonotal tubercles well developed, acute, sometimes weakly tuberculate apically. Propodeal carinae low, sometimes serrate, with low posterodorsal denticles.

Metasoma. Petiole with two low, reduced dorsal denticles, node of postpetiole with two faint, short dorsal carinae, and two low lateral carinae, best seen in dorsolateral view. Postpetiole in dorsal view sometimes slightly posteriorly emarginate. First gastral tergite with lateral and dorsal carinae strongly developed.

S. scrobifer queen, male, and larva.

Unknown.

S. scrobifer geographic range.

Brazil, Paraguay. Map: Figure 35.

S. scrobifer notes.

S. scrobifer is most similar to its sister species, S. maravalhas , from which scrobifer can be separated by its larger size; much wider, trapeziform frontal lobes; larger, more protruding eyes; and stronger frontal carinae. The combination of large eyes, trapeziform frontal lobes, and four carinae on the gaster will separate it from all other Sericomyrmex species. Smaller individuals can have less pronounced mesonotal tubercles and weaker dorsal and lateral gastral carinae.

S. scrobifer material examined.

BRAZIL: Bahia: Vitória da Conquista, -14.84, -40.84, 27 Jan 1997, J. H. C. Delabie; Goiás: Faz. Cachoeirinha, Jataí, [-17.89, -51.70], 28 Oct 1962, Exp. Dep. Zool.; Mato Grosso: Utiariti, Rio Papagaio, [-13.03, -58.28], 23 Oct 1966, Lenko, Pereira; Minas Gerais: Santana do Riacho, -19.17, -43.72, 19 Feb 2001, S. M. Soares; Uberlândia, Clube Caça, Pesca, [-18.97, -48.28], 14 Sep 2007, R. M. Feitosa; Uberlândia, Panga, -19.1667, -48.3833, 816m, 2 Sep 2008, T. R. Schultz; Paraná: Jaguariaíva, -24.168, -49.667, 804m, 15 Jan 2015; Piaui: Rio Uruçuí-Preto, [-7.3431, -44.6168], 20 Feb 1976, R. Negrett; São Paulo: São Paulo, [-21.8, -48.5], 26 May 1905, N. A. Weber; Agudos, [-22.46, -48.97], 27 Apr 1952, W. W. Kempf; Faz. Itaquerê, Boa Esperança do Sul, [-21.9802, -48.3881], 25 Jan 1964, K. Lenko; Mogi Guaçu, -22.37, -46.94, 570m, 6 Feb 1997, I. R. Leal; Tocantins: Cartucho e Goiatins, [-8.10, -47.64], 9 Nov 1998, C. R. F. Brandão, C. I. Yamamoto. PARAGUAY: Canindeyú: Reserva Mbaracayú, Aguara Ñu, -24.1833, -55.2833, 240m, 16 Nov 2002, A. L. Wild.