Scaura atlantica Melo

Melo, Gabriel A. R. & Costa, Marco Antônio, 2004, A new stingless bee species of the genus Scaura (Hymenoptera, Apidae) from the Brazilian Atlantic forest, with notes on S. latitarsis (Friese), Zootaxa 544, pp. 1-10 : 7-9

Scaura atlantica Melo , sp. nov.

( Figs. 2, 4, 6 , 8, 10, 12–15 )

Comments and Diagnosis

Scaura atlantica , sp. nov., is one of the forms which, according to Schwarz’s (1948) revision, would be considered as latitarsis . However, there are many morphological differences between them. This species can be distinguished from latitarsis by its larger body size, darker color, smoother upper frons ( Fig. 4 ), shorter simple setae on the frons, disc of mesocutum and terga 4–5 ( Figs. 4, 6 , 12 , respectively), plumose setae on frons with shorter branches ( Fig. 4 ), presence of brown simple setae on upper mesepisternum and by the contour of posterior margin of the hind basitarsus ( Fig. 10 ). From S. argyrea , it differs by possessing a frons with shorter simple setae and whose sockets are less protuberant, shorter simple setae on the mesoscutum and by the shape of the hind basitarsus.

This new species has been collected in the Atlantic forest of southern Bahia and northern Espírito Santo, in eastern Brazil, including the basin of the Jequitinhonha river, in the state of Minas Gerais ( Fig. 13 ). It is possible that the specimens from Ilha Grande, in Rio de Janeiro, listed by Schwarz (1948) under S. latitarsis , belong to S. atlantica .

Description

Worker holotype. Body length: 3.7 mm; maximum head width: 1.81 mm; forewing length: 4.1 mm; maximum width of T2: 1.3 mm. Color: Integument predominantly black. Apical third of mandibles dark reddish brown. Scape entirely black, except for reddish brown radicle. Last three tarsomeres reddish brown. Terga brown and sterna light brown. Tegulae, wing veins and pterostigma dark brown; wing membrane hyaline. Pubescence: Longest simple setae on upper frons with 0.10–0.12 mm in length; those on the scape with about 0.04 mm. Longest simple setae on disc of mesoscutum 0.09–0.10 mm long; short, plumose pubescence brown, less branched than in S. latitarsis . Simple setae on posterior portion of upper mesepisternum brown. Erect setae on posterior margin of T2–5 brown, those on T6 brown to white; longest setae on mid portion of T3 with 0.05–0.06 mm in length, on T4 with 0.06–0.07 mm, and on T5 with 0.07–0.08 mm. Integumental surface: Predominantly smooth and shiny. Frons, between setal punctures, smooth, reticulations restricted to area around ocelli; sockets of simple setae on upper frons and vertex only weakly raised. Structure (measurements in mm): Head about 1.3x wider than long (1.81:1.38); proportion between upper (tangential to lower rim of mid ocellus), maximum and lower interorbital distances, 0.86:1:0.76 (1.1:1.28:0.98); clypeus 2x wider than long (0.85:0.43); scape, excluding radicle, about 6.4x longer than its maximum width (0.70:0.11); proportion between pedicel, 1st and 2nd flagellomeres, 1.5:1:1.2 (0.15:0.1:0.12); ocelo­orbital distance, in dorsal view, 0.63x distance between posterior ocelli (0.22:0.35). Hind basitarsus, in inner view, about 1.8x longer than its maximum width (1.2:0.67).

Type material

Brazil, Bahia: holotype worker, “ Brasil, Bahia, Ilhéus, / Campus da UESC, / 10.i.2003, G. Melo & / M. Costa Ninho A”. Paratypes: 6 workers, same data as holotype; 8 workers, same data except “Ninho B”; 4 workers, “DPTo. ZOOL / UF ­PARANÁ” and “URUÇUCA ­ BAHIA / BRASIL 27/II/72 / V. Graf leg.”; Espírito Santo: 30 workers, “DPTo. ZOOL / UF ­ PARANÁ” and “ SÃO ROQUE ­ E. SANTO / BRASIL 24­29/IV/67 / C. & C. T. Elias leg.”; 1 worker, “DPTo. ZOOL / UF ­ PARANÁ” and “ CONC. DA BARRA ­ ES / BRASIL ­ 12/V/1969 / Claudionor Elias”; Minas Gerais: 2 workers, “Penedo: Fazenda / Penedo­Serrinha / 1995­6115” and “Itamarandiba MG / BRASIL 12/ 01/1998 / F. A. Silveira”. Holotype and most paratypes in DZUP, 4 paratypes in RPSP and 1 paratype in DZMG.

Biology

Three nests were found in a secondary forest within the campus of the Universidade Estadual de Santa Cruz, in Ilhéus, Bahia. Similarly to the other species of the latitarsis group, all nests were build within active nests of Nasutitermes ( Fig. 14 ). The termite nests (and the bee’s nest entrance) were between 1 to 1.7 m from the ground. The entrance tubes were build with a reddish yellow and soft cerumen ( Fig. 15 ) and measured between 2 to 3 cm in length. The entrance itself had an oval contour whose longer axis measured about 7 mm and the shorter axis around 5 mm. One nest was opened and presented an internal architecture very similar to that described by Camargo (1970).

Figures

FIGURE 13. Map of South America showing the known locality records for Scaura latitarsis (solid triangles) and S. atlantica, sp. nov. (solid circles), in Brazil.

FIGURES 1 – 6. (1, 3, 5) Scaura latitarsis, worker (from Uberaba, Minas Gerais): head, in frontal view (1) and detail of upper frons (3); upper portion of mesosoma, in lateral view (5). (2, 4, 6) Scaura atlantica, sp. nov., worker (from Ilhéus, Bahia): head, in frontal view (2) and detail of upper frons (4); upper portion of mesosoma, in lateral view (6). For figs 1 – 2, scale bar = 1.0 mm; for figs 3 – 4, 0.3 mm; and for figs 5 – 6, 1.0 mm.

FIGURES 7 – 12. (7, 9, 11) Scaura latitarsis, worker (from Uberaba, Minas Gerais, except fig 9, material from Alpinópolis, Minas Gerais): base of antenna, in frontal view (7); hind leg, in outer view (9); apical portion of metasoma, in lateral view (11). (8, 10, 12) Scaura atlantica, sp. nov., worker (from Ilhéus, Bahia): base of antenna, in frontal view (8); hind leg, in outer view (10); apical portion of metasoma, in lateral view (12). For figs 7 – 8, scale bar = 0.3 mm; for figs 9 – 10, 1.0 mm; and for figs 11 – 12, 0.5 mm.

FIGURES 14 – 15. Termite nest (Nasutitermes) used as nesting substrate by the stingless bee Scaura atlantica, sp. nov (14); scale bar = 50 mm. Detail of the entrance tube of the bee’s nest. Notice an older tube collapsed under the active one (15); scale bar = 15 mm.