Tapinoma atriceps Emery, 1888

Escarraga, Mayron E., Lattke, John E., Pie, Marcio R. & Guerrero, Roberto J., 2021, Morphological and genetic evidence supports the separation of two Tapinoma ants (Formicidae, Dolichoderinae) from the Atlantic Forest biome, ZooKeys 1033, pp. 35-62 : 35

Tapinoma atriceps Emery, 1888 Figs 1A, B , 2A, D , 3A, D , 4 , 5

Tapinoma (Micromyrma) atriceps Emery, 1888: 363. Syntype series (several workers, queens, males): Brazil, Rio Grande do Sul (v. Ihering) [MSNG, AntWeb image of syntype examined]. One syntype worker (CASENT0904029) here designated lectotype.

Tapinoma atriceps Emery. Kempf 1972: 247.

Tapinoma atriceps Emery. Shattuck 1994: 142.

Tapinoma atriceps Emery. Bolton 2021: e-catalogue (http://antcat.org).

Worker diagnosis.

Lateral margin of head in frontal view distinctly convex. Compound eye with 9 or 10 ommatidia along maximum diameter. Scape long (SI> 93). In profile, dorsal margin of propodeum forms distinct angle with propodeal declivity; dorsal margin short, about 1/4 length of declivitous margin (Fig. 4B ).

Worker. Measurements (n = 26): HL 0.58 ± 0.04 (0.52-0.64), HW 0.50 ± 0.03 (0.42-0.55), SL 0.57 ± 0.04 (0.50-0.63), WL 0.69 ± 0.06 (0.60-0.78). Indices: CI 86 ± 3 (78-91), SI 97 ± 3 (93-103).

Head in full-face view oval, longer than wide, lateral margin convex, posterior margin slightly convex to straight (Fig. 1A ). Maxillary palp relatively filiform, long, extending posteriorly beyond half of head. Masticatory margin of mandible with one large apical tooth, followed by two smaller teeth, fourth tooth larger than third, and then followed by denticles. Anterior margin of clypeus slightly emarginate medially. Scape almost as long as HL or greater (SI>93), surpassing posterior margin of head by distance equal to or greater than pedicel. In lateral view, dorsal margin continuously convex; metanotal groove weakly impressed; propodeum in lateral view slightly below level of mesonotum. Integument weakly imbricate, with exception of smooth petiole. Body covered by short, appressed pubescence. Head (excluding clypeus), antenna, and mesosoma lacking erect setae; clypeus with 6 long setae. Gastric tergites bearing erect hairs near their posterior margins: 2 hairs on first tergite, 2-4 on second, 4-6 on third, and 6-10 on fourth. Head and gaster medium brown; antennae, mesosoma, legs and petiole whitish yellow; mesosoma with brown spot on mesopleuron, spot sometimes present on lateroposterior corners of pronotum, metapleuron, and sides of propodeum.

Queen. Measurements (n = 4): HL 0.73 ± 0.03 (0.70-0.76), HW 0.68 ± 0.04 (0.64-0.71), SL 0.60 ± 0.02 (0.58-0.62), WL 1.23 ± 0.13 (1.08-1.32). Indices: CI 94 ± 3 (91-97), SI 83 ± 1 (82-83).

Head subquadrate in full-face view, slightly longer than broad (CI 91-97), lateral margin very convex, posterior margin straight to slightly convex (Fig. 2B ). Mandibular masticatory margin with one large apical tooth, followed by 2 smaller teeth, fourth tooth larger than third, followed by 5 smaller teeth, and then small denticles decreasing in size. Anterior margin of clypeus slightly emarginate medially. Scape relatively long, reaching or surpassing posterior margin of head by length shorter than that of pedicel (SI 82-83). Forewing with crossveins 2r-rs, 2rs-m, and cu-a present (Fig. 2C, D ). Hindwing with cu-a present, cubitus short, not projected after 1rs-m+M. Integument weakly imbricate; mesopleuron smooth. Body covered by short yellowish pilosity, excepting glabrous petiole. Clypeus bearing 6 long setae; gastric tergites each bearing several erect setae near their posterior margins. Body color medium brown; palps, flagella, coxae, trochanter, tibiae, tarsi, and petiole whitish yellow; propodeum usually brown, but sometimes with whitish-yellow spot on posterodorsal region. Gastric tergites I-III with pale-yellow, posterior transverse strip.

Male. Measurements (n = 4): HL 0.48 ± 0.04 (0.44-0.51), HW 0.52 ± 0.02 (0.50-0.53), SL 0.36 ± 0.04 (0.32-0.41), WL 0.63 ± 0.02 (0.61-0.66). Indices: CI 105 ± 11 (92-114), SI 76 ± 5 (71-82).

Head rounded in dorsal view; posterior margin slightly interrupted by posterior ocelli; anterior margin of clypeus straight to weakly emarginate medially. Eye large, rounded. Scape long, reaching or surpassing posterior head margin. Mandible semi-falcate; masticatory margin with large apical tooth followed by denticles of similar size forming a serrated surface continuing indistinctly up to the mandibular basal margin. Integument feebly imbricate, katepisternum smooth. On forewing, 1m-cu absent, median short. On hindwing, free section of radial and cu-a present, free section of cubitus absent. Row of long setae present on posterior margin of fore and hindwings. Head, scutum, and gaster covered by moderate, yellow, short, appressed hairs; scutellum glabrous. Hairs absent to scarce on pronotum, mesopleuron, propodeum, and petiole. Antenna covered by short, decumbent hairs. Gastric tergites I-V lacking erect setae. Head, mesosoma, petiole, and gaster dark brown. Antenna and legs light brown.

Distribution.

Tapinoma atriceps occurs in Argentina, Brazil, and Paraguay (Fig. 5 ). In Argentina, this species is present in the northeastern corner of the country, in the province of Misiones. In Brazil, our records show the presence of this species in the states of Mato Grosso do Sul, Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina, and São Paulo. In Paraguay, T. atriceps occurs in the department of Canindeyú.

Biology.

Tapinoma atriceps is an arboreal ant which can be found from the understory layer to the canopy and rarely on the ground. We found nests of this ant in hollow cavities of the vegetation or dry hanging branches, in plants of the families Poaceae ( Bambusoideae ), Melastomataceae , Piperaceae , and Urticaceae . Workers are commonly found foraging on the leaves of plants near the nest. The colony can be moderately large, with more than 312 workers, and in a couple of nests we found four dealate queens, evidencing polygyny as in other species of Tapinoma (e.g., Bustos and Cherix 1998; Buczkowski and Bennet 2008).

Material examined.

Argentina • 2 queens, 2 workers; Misiones, Parque Provincial Teyú Cuaré; 27°17.08'S, 55°35.62'W; 28 Dec. 2007; W. Mackay and E. Mackay legs; WEMC. BRAZIL • 1 worker; Mato Grosso do Sul, Dourados, Fazenda Azulão; 22°12.800'S, 54°55.133'W; 10 Mar. 2006; M. Santana and A.Vieira legs; DZUP • 2 males, 4 workers; Minas Gerais, Alto Caparaó, Parque Nacional Caparaó, 20°25.155'S, 41°51.083'W; 5-20 Dec. 2011; J. Chaul leg. DZUP • 1 worker; Minas Gerais, Lavras, Fragmento 06; Dec. 2002; M.S. Santos and N.S. Dias legs; CEPLAC • 1 queen; Minas Gerais, Pedra Azul; alt. 800 m; Nov. 1972, Seabra and Alvarenga legs; MZSP 10657 • 2 workers; Minas Gerais, Pedra Azul, Seabra and Alvarenga legs; MZSP 10658 • 1 worker, 1 queen; Minas Gerais, Serra do Cipó, 19°25.155'S, 43°51.083'W; 26 Ju. 2016; F. Siqueira leg.; DZUP • 1 worker; Minas Gerais, Viçosa, Mata do Paraíso; 1997/1998; S. de M. Soares leg.; CEPLAC • 1 male, 1 queen, 1 worker; Paraná, Antonina, Reserva Natural Guaricica, 25°17.794'S, 48°39.592'W; 26 Dec. 2016; C. da Costa leg.; DZUP • 1 queen, 1 worker; Paraná, Antonina, Reserva Natural Guaricica; 25°18.354'S, 48°39.678W; 29 Oct. 2016; M. Escárraga leg.; DZUP 548798 • 1 worker; Paraná, Antonina, Reserva Natural Guaricica; 10-13 Jul. 2016; M. Escárraga leg.; DZUP 548797 • 2 workers; Paraná, Guaraqueçaba, Reserva Natural Salto Morato, 25°09.816'S, 48°17.880'W; 8 Dec. 2016; M. Escárraga leg.; DZUP 548784 • 1 worker; Paraná, Paranaguá, Parque Estadual do Palmito ; 25°35.016'S, 48°32.496'W, 28 Apr. 2016; M. Escárraga leg.; DZUP 548786 • 2 workers; Paraná, Pq. Marumby, Km 34, Estr. Graciosa; 3 Oct. 1980; A.L. Lozovei leg.; MZSP14069 • 1 worker; Rio Grande do Sul; MZSP11439 • 1 worker; Rio Grande do Sul, Porto Alegre, Morro São Pedro, 30°10.824'S, 51°06.078'W; L. Kaminski leg.; DZUP • 2 workers; Rio Grande do Sul, Porto Alegre; 30°10.824'S, 51°06.078'W; 27 Dec. 2016; M. Escárraga leg.; DZUP 548788 • 3 workers; Santa Catarina, Blumenau; alt. 120 m; 19 Jan. 1972; W.W. Kempf leg.; MZSP 7049 • 1 worker; Santa Catarina, Brusque, RPPN Chácara Edith; 27°05.692'S, 48°53.581'W; 28 Feb. 2013; Y. Gadelha leg.; DZUP • 1 worker; Santa Catarina, Florianópolis, Naufragados; 27°49.405'S, 48°33.694'W; 19 Feb. 2016; J. Chaul leg.; DZUP • 2 workers; Santa Catarina, Florianópolis; 27°35.928'S, 48°25.962'W; 25 Feb. 2017; M. Escárraga leg.; DZUP 548789 • 1 worker; Santa Catarina, Florianópolis, Praia Mole, 27°35.927'S, 48°25.962'W; 25 Feb. 2017; A. Menezes leg.; DZUP • 2 workers; Santa Catarina, Seara, Nova Teutônia; Jul. 1959; F. Plaumann leg.; MZSP • 1 worker; Santa Catarina, Seara, Nova Teutônia; 19 Dec. 1972; F. Plaumann leg.; MZSP8566 • 2 workers; Santa Catarina, Palhoça, Parque Estadual da Serra do Tabuleiro ; 27°44.467'S, 48°41.833'W; 2-10 Jun. 2003; winkler 30; R.R. Silva, B. H. Dietz and A. Tavares legs.; MZSP • 3 workers; Santa Catarina, Seara, 24°07'S, 52°18'W; Jul. 1999; R. R. Silva leg.; Transecto II Isca Veget.; MZSP • 1 worker; Santa Catarina, Seara; Jul. 1958; F. Plaumann leg.; MZSP 2719 • 1 worker; Santa Catarina, Santo Amaro da Imperatriz , Parque Estadual da Serra do Tabuleiro , 27°55.356'S, 48° 50.277'W; 26 Nov. 2013; Y. Gadelha leg.; DZUP • 1 male, 1 queen, 1 worker; São Paulo, 8 Km SW Jundiaí; 23°14'S, 46°56'W; alt. 1180m,; 28 Dec. 1993; Manual; P.S. Ward leg.; [PSWC 12463] • 2 queens, 3 workers; São Paulo, Ilha da Vitoria , 29 Mar.-6. Apr. 1965; Exp. Depto. Zool. legs; MZSP 4083 • 1 queen; São Paulo, Ilha da Vitoria ; 16-27 Mar. 1964; Exp. Depto. Zool. leg.; MZSP 4176 • 3 workers; São Paulo, Ilha da Vitoria ; 29 Mar.-6 Apr. 1966; Exp. Depto. Zool. leg.; MZSP 4117; • 2 workers; São Paulo, Ilha do Cardoso ; Jan. 1979; Liliana Foneris leg.; MZSP • 2 workers; São Paulo, Salesópolis, Est. Biol. Boracéia; 11 Nov. 1960; K. Lenko leg.; MZSP 1788 • 4 workers; São Paulo, Salesópolis, Est. Biol. Boracéia; 13 Nov. 1960; K. Lenko leg.; MZSP 1483 • 1 worker; São Paulo, Salesópolis, Est.Biol. Boracéia, 3-5 May 1996; Brandão, Agosti, Diniz, Silvestre and Yamamoto legs; MZSP • 6 workers; São Paulo; USNM • 1 worker; São Paulo, Ubatuba, Parque Estadual Serra do Mar ; 23°17.940'S, 44°47.220'W; 3-14 Mar. 2008; F. Esteves and R. Feitosa legs; MZSP • PARAGUAY. 1 worker; Canindeyú, Res. Nat. Bosque Mbaracayú, Jejuimí; alt. 107 m; 28 May-5 Jul.1996; Malaise ; A.C.F. Costa leg.; ALWC .

Figures

Figure 1. Tapinoma atriceps and T. breviscapum workers A head in frontal view of T. atriceps B body in lateral view of T. atriceps C head in frontal view of T. breviscapum D body in lateral view of T. breviscapum. Photographed specimens and those included in the molecular analyzes (haplotypes H 04 and H 08 respectively) are nestmates. Specimens deposited in DZUP. Photographs by M. Escarraga.

Figure 2. Tapinoma atriceps and Tapinoma breviscapum queen A body in lateral view of T. atriceps B head in frontal view of T. atriceps C anterior wing of T. atriceps D posterior wing of T. atriceps E head in frontal view of T. breviscapum F body in lateral view of T. breviscapum. Photographed specimens and those included in the molecular analyzes (haplotypes H 04 and H 08 respectively) are nestmates. Specimens deposited in DZUP. Photographs by M. Escarraga.

Figure 3. Tapinoma atriceps from Antonina, Reserva Natural Guaricica (Parana, Brazil) and T. breviscapum from Serra do Cipo (Minas Gerais, Brazil) male A habitus of T. atriceps B head in frontal view of T. atriceps C anterior wing of T. atriceps D posterior wing of T. atriceps E head in frontal view of T. breviscapum F habitus of T. breviscapum. Specimens deposited in DZUP. Photographs by M. Escarraga.

Figure 4. SEM microphotographs of Tapinoma atriceps from Serra do Cipo (Minas Gerais, Brazil) A worker head in dorsal view B worker mesosoma in lateral view C queen head in dorsal view D queen mesosoma in lateral view. The box with dashed lines indicates pubescence on the frons between the frontal carinae. Specimens deposited in DZUP.

Figure 5. Distribution map of Tapinoma atriceps and T. breviscapum. The figures with red outline correspond to the localities for the sequenced specimens. Dark green area in the main map corresponds to the Atlantic Forest domain defined by the WWF.