Revista de la Sociedad Entomológica Argentina ISSN: 0373-5680 [email protected] Sociedad Entomológica Argentina Argentina ROIG ALSINA, Arturo A review of the albidohirta group of Ptilothrix (Hymenoptera: Apidae: Emphorini) Revista de la Sociedad Entomológica Argentina, vol. 66, núm. 3-4, 2007, pp. 113-119 Sociedad Entomológica Argentina Buenos Aires, Argentina Available in: http://www.redalyc.org/articulo.oa?id=322028491014 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative ISSN 0373-5680 Rev. Soc. Entomol. Argent. 66 (3-4): 113-119, 2007 113 A review of the albidohirta group of Ptilothrix (Hymenoptera: Apidae: Emphorini) ROIG ALSINA, Arturo Museo Argentino de Ciencias Naturales «Bernardino Rivadavia,» Av. Angel Gallardo 470, 1405 Buenos Aires, Argentina; e-mail: [email protected] Revisión del grupo albidohirta de Ptilothrix (Hymenoptera: Apidae: Emphorini) RESUMEN. El grupo albidohirta de Ptilothrix Smith incluye tres especies: Ptilothrix albidohirta Brèthes, P. concolor sp. nov. y P. nemoralis sp. nov. Este grupo se conoce del oeste y norte de la Argentina y del centro de Bolivia. Una de sus especies, P. albidohirta, llega hasta los 3.600 m s.n.m. en la cordillera de los Andes, en tanto que las otras dos especies habitan en el llano. Se caracteriza el grupo y se describen e ilustran las especies. PALABRAS CLAVE. Abejas. Emphorini. Argentina. Bolivia. ABSTRACT. The albidohirta group of Ptilothrix Smith includes three species: Ptilothrix albidohirta Brèthes, P. concolor sp. nov., and P. nemoralis sp. nov. The group is known from northern and western Argentina and from central Bolivia. One of its species, P. albidohirta, reaches high altitudes in the Andes mountains, up to 3600 m a.s.l., while the other two species occur in the lowlands. A characterization of the group, descriptions of the species, and illustrations are provided. KEY WORDS. Bees. Emphorini. Argentina. Bolivia. INTRODUCTION occurs in temperate South America, but the number of species is difficult to assess, since The genus Ptilothrix Smith is a member of Ptilothrix has not been reviewed to date. the Emphorini, a tribe of bees restricted to Species of Ptilothrix are solitary, the Western Hemisphere (Michener, 2000). burrowing bees. Many species are The tribe comprises ten genera (Roig-Alsina, oligolectic, and have been associated with 1999), six of which are restricted to South plants mainly of the families Malvaceae, America, two are broadly distributed Onagraceae, Convolvulaceae, and throughout the continent, and two (Diadasia Cactaceae (Linsley et al., 1956; Rust, 1980; Patton and Ptilothrix Smith) have numerous Hazeldine, 1997). species in North and South America, but are According to Roig-Alsina (1994) and Sipes scarce or not represented in Central America. & Tepedino (2005), Ptilothrix shares derived The species of Ptilothrix occur from north- features with Diadasina Moure and central eastern U.S.A. to the state of Morelos Alepidosceles Moure, suggesting that these in Mexico (Michener et al., 1994), and from three genera are closely related. Ptilothrix is northern Brazil to northern Patagonia in distinguished, among other emphorines, by Argentina. The largest diversity of the genus a suite of characters that includes the lack of Recibido: 19-IV-2007; aceptado: 28-VIII-2007 114 Rev. Soc. Entomol. Argent. 66 (3-4): 113-119, 2007 arolia, the elongate first flagellomere, the MATERIAL AND METHODS bowed, elevated upper margin of the clypeus coupled with a short proboscis, the reduced Terminology for structures follows apical projection of the female hind Michener (1944, 2000), except that basitarsus, and the type of scopal hairs on metapostnotum is used instead of propodeal the outer surface of the hind tibia, which have triangle (Brothers, 1976). The maximum the branches not retrorse, but arising at acute diameter of the median ocellus (MOD) is used angles to the axes of the hairs and directed as a reference to express the length of the apicad. pubescence and other structures. In the The present contribution deals with a descriptions, the metasomal terga (T) and small group of species restricted to northern sterna (S) are identified with Arabic numerals. Argentina and Bolivia. Although the three Specimens studied are deposited in the species included in the group are following institutions: Museo Argentino de morphologically homogeneous, they are Ciencias Naturales «Bernardino Rivadavia,» strikingly different in their color pattern and Buenos Aires (MACN); Museo de La Plata, vestiture. La Plata (MLP); Instituto y Fundación Miguel Figs. 1-9. Figs. 1-3, Ptilothrix concolor n. sp., male. 1, S7, ventral (left) and dorsal (right) views. 2, S8, ventral view. 3, apex of T7. Figs. 4-6. Ptilothrix albidohirta Brèthes, male. 4, S7, ventral (left) and dorsal (right) views. 5, S8, ventral view. 6, apex of T7. Figs. 7-9, hairs of center of outer surface of hind tibia of female. 7, P. albidohirta Brèthes. 8, P. concolor n. sp. 9, P. nemoralis n. sp. Scale bars = 0.1 mm. ROIG ALSINA, A. The albidohirta group of Ptilothrix 115 Fig. 10. Distribution map of the species of the albidohirta group: P. albidohirta Brèthes (dots), P. concolor n. sp. (stars; open star indicates imprecise locality in La Rioja province), and P. nemoralis n. sp. (diamonds). Lillo, Tucumán (IFML); American Museum of and P. nemoralis in the Chaco region. Natural History, New York (AMNH); The group is characterized by the slender, Zoologische Staatssammlung, München short-branched scopal hairs on the outer (ZSM). Acronyms are used to indicate surface of the hind tibia of the female, by the depositories of the specimens. lack of an apical white brush of hairs on the hind tibia, and by the digitiform projection RESULTS of the inner lobe of the seventh sternum of the male (although males of P. nemoralis are albidohirta group as yet unknown). The three species differ considerably in This species-group includes Ptilothrix their appearance. Ptilothrix albidohirta albidohirta Brèthes and the two new species resembles Diadasia baeri (Vachal), another P. concolor and P. nemoralis. The group is hirsute, pale-colored emphorine, with which known from northern and western Argentina it is sympatric in the Andes mountains. and from central Bolivia (Fig. 10). One of the Ptilothrix concolor resembles a large, species, P. albidohirta, occurs in the Puna ordinary Diadasia, due to its short, appressed, region, reaching high altitudes; records for yellowish-brown vestiture. On the contrary, this species range from 2200 m to 3600 m Ptilothrix nemoralis bears a color pattern that a.s.l. The other two species occur in the is typical for a large number of species of lowlands, P. concolor in the Monte region Ptilothrix, with a rufous dorsum of the thorax 116 Rev. Soc. Entomol. Argent. 66 (3-4): 113-119, 2007 and a yellow banded metasoma. shiny, elevated, giving rugose appearance. Punctation around and above antennal Ptilothrix albidohirta Brèthes, 1910 sockets similar to that of clypeus, but with (Figs. 4-7, 10) tessellate interspaces; rest of head more finely punctured; vertex around ocelli finely Ptilothrix albidohirta Brèthes, 1910: 295-296 tessellate, except small shiny area close to (Holotype male, 7892, Jujuy, Argentina, lateral ocellus. Punctures on scutum, MACN, examined); Schrottky, 1913: 254; scutellum, and mesopleuron dense, on center Hazeldine, 1997: 33-35, figs. 16-17 of scutum 0.2-1.0 diameters apart, with (biology); Roig-Alsina, 1999: 25. weakly tessellate interspaces. Metapostnotum tessellate. Metasomal terga tessellate between Diagnosis. This species is distinguished punctures. by its hirsute vestiture all over the body. The Structure. Inner orbits nearly straight and metasoma of both sexes is clothed with long, parallel. Ocellocular and interocellar erect hairs, lacking the appressed bands distances subequal. Clypeus 1.9-2.0 times characteristic of many other Ptilothrix. It is wider than long, protuberant in lateral view also characterized by the color of the for a distance 0.65 times maximum eye vestiture, greyish on the head and mesosoma, width. Labrum trapeziform, with pointed and yellowish to orange on the metasoma; apex, 1.5 times as broad as median length. the vestiture of the legs is pale in males, but Interantennal distance 2.5-2.8 times mostly black in females. antennocular distance. First flagellomere 2.2 times longer than its apical width; proportion Redescription. Female. Length: 10.3- of lengths of scape, pedicel and proximal 12.8 mm; length of forewing: 8.8-10.3 mm. three flagellomeres 1.7:0.5:1:0.3:0.35. Color: Black, except middle of mandible, apex of tarsi, and translucent outer margin of Male. Length: 8.0-13.0 mm (holotype tegula reddish brown. Membrane of wings: 10.3 mm); length of forewing: 8.5-10.5 mm slightly infuscate; pterostigma and veins: dark (holotype, 8.7 mm). Color, pubescence and brown to black. sculpture: similar to those of female, except Pubescence. Hairs: gray to pale as follows. Hairs: gray to pale yellowish- yellowish-brown on head, mesosoma and T1; brown all over the body, including legs and hairs grayish, partly dusky, on underside of metasoma. Hairs on head and thorax longer, coxae, trochanters and front and mid femora, those on scutum 3.5-4.3 times MOD, on rest of legs with hairs black, including scopal mesopleuron 3.3-4.3 times MOD. Hairs on hairs. Hairs: yellowish brown (with orange metasomal terga: erect, long, on T2 2.2-2.8 hue in fresh specimens) on T2-T6 and on times MOD. S2-S4 with long, erect hairs, and metasomal sterna; prepygidial fimbria orange. apical fringes poorly defined; S5 with hairs Pubescence of head and thorax: long and short medially and longer laterally. S6 bare erect, hairs on center of scutum 2.5-3.0 times basally and laterally, apically with dense MOD, hairs on mesopleuron also 2.5-3.0 median tuft of erect hairs.