Plectoplebeia, a New Neotropical Genus of Stingless Bees (Hymenoptera: Apidae)
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ZOOLOGIA 33(1): e20150153 ISSN 1984-4689 (online) www.scielo.br/zool TAXONOMY AND NOMENCLATURE Plectoplebeia, a new Neotropical genus of stingless bees (Hymenoptera: Apidae) Gabriel A.R. Melo1 1Laboratório de Biologia Comparada de Hymenoptera, Departamento de Zoologia, Universidade Federal do Paraná. Caixa Postal 19020, 81531-980 Curitiba, PR, Brazil. E-mail: [email protected] ABSTRACT. A new stingless bee genus, Plectoplebeia gen. nov., is proposed to accommodate a peculiar Neotropical species currently placed in Plebeia Schwarz, 1938. The brief, but convoluted taxonomic history of its type species, Trigona nigrifacies Friese, 1900, is documented, with Trigona (Plebeia) intermedia Wille, 1960 being placed as its junior synonym. Plectoplebeia gen. nov. resembles an enlarged species of Plebeia, differing by its larger body size, wider distance between the clypeus and the eye, presence of a shallow depression on the frons above the antennal sockets, coarser punctures on the head and mesosoma, a shorter, convex scutellum, an elongate propodeum and metapostnotum, long wings, with a higher number of hamuli, and by an elongate metasoma, with an unusually long first tergum. The single included species,Plectoplebeia nigrifacies comb. nov., is known only from the Bolivian Yungas, an ecoregion extending from west-central Bolivia to southeastern Peru. KEY WORDS. Bolivia, Meliponini, Peru, taxonomy, Yungas. Currently a total of 32 genera are recognized for the extant lineages that fall outside the genera to which they are related Neotropical fauna of stingless bees (CAMARGO & PEDRO 2007). This (ROUBIK et al. 1997, CAMARGO & ROUBIK 2005). classification system was laid down along the 20th century and mostly through the work of Moure, who departed from contem- MATERIAL AND METHODS poraneous authors in raising to genus-level the many subgenera of Trigona Jurine, 1807 and for proposing additional new genera Material from the following institutions was examined: (MOURE 1942, 1943, 1944, 1946, 1950, 1951, 1953, 1989, CAMAR- DZUP – Coleção de Entomologia Pe. Jesus Santiago Moure, Uni- GO & MOURE 1983). In a summary presented by MOURE (1961), a versidade Federal do Paraná, Curitiba, Brazil; ZMB – Museum total of 28 genus-group names, involving 11 genera, were then für Naturkunde, Berlin, Germany. The following collection is recognized in his classification of the New World stingless bees. also cited in the text: SEMK – Division of Entomology, Natural Moure’s classification system, including additions from sub- History Museum, University of Kansas, Lawrence, USA. In the sequent authors, has close association with biological features of list of type material, the quotation marks indicate the different the taxa at genus-level, in particular details of their nesting habits labels for the same specimen, the backslashes (\) indicate dif- (CAMARGO & MOURE 1988), and more recently has been corroborated, ferent lines on the same label. to a great degree, by independent evidence from molecular data The format of the genus description follows that of CAMAR- (COSTA et al. 2003, RASMUSSEN & CAMERON 2010). In the comprehen- GO & ROUBIK (2005), with distinctive or autapomorphic characters sive study by RASMUSSEN & CAMERON (2010), however, a few taxa highlighted in boldface. The general morphological terminology came out as paraphyletic (Leurotrigona Moure, 1950 and Scaura follows URBAN (1967), SILVEIRA et al. (2002) and MICHENER (2007). Schwarz, 1938) or polyphyletic (Plebeia Schwarz, 1938), indicating Antennal flagellomeres are indicated as F1, F2, etc.; metasomal that further studies are needed to improve the current classification. terga and sterna, respectively, as T1 to T7, and S1 to S8. The The purpose of the present contribution is to propose a density of punctation and intervals between the punctures are new genus-level taxon for a peculiar Neotropical species cur- based on relative puncture diameter, pd (e.g. <1pd: less than rently placed in the genus Plebeia. The distinct features of this 1x the puncture diameter between the punctures). The color taxon have been discussed by WILLE (1960, 1979) and MICHENER images of the holotype of Trigona nigrifacies were obtained on (1990). The two most recently proposed stingless bee genera a camera Nikon Coolpix 995 attached to a stereomicroscope for the Neotropical fauna, Meliwillea Roubik, Lobo & Camargo, Leica MZ7, while those of the paratype of Trigona intermedia 1997 and Paratrigonoides Camargo & Roubik, 2005, are also both on a Leica DFC295 in a stereomicroscope Leica M125; in both monotypic, each with a single species representing relictual cases the images were processed by the software Zerene Stacker. ZOOLOGIA 33(1): e20150153 | DOI: 10.1590/S1984-4689zool-20150153 1 / 8 GAR Melo TAXONOMY having examined and labeled the type specimen, EARDLEY (2004) does not mention it in his revision of the African stingless Plectoplebeia gen. nov. bees. Probably trusting Eardley’s identification as correct, C. Rasmussen also added a label, dated from 2007, to warn of the urn:lsid:zoobank.org:act:BFA974A0-1CA9-4CBE-A148-C1B5EDFB8800 supposedly wrong locality data (Fig. 1). Type species: Trigona nigrifacies Friese, 1900. This mistaken interpretation of Friese’s species was prob- Diagnosis and Comments. At a first glance, the type ably triggered by where the type specimen has been placed in species of Plectoplebeia resembles just an enlarged Plebeia. The the ZMB collection. It has been curated under the name “Trigona somewhat rounded head shape, a mostly smooth, shiny integu- beccarii v. nigrifacies”, a homonymous taxon described by FRIESE ment, a relatively short body pilosity and possession of a narrow (1912) from Africa (Fig. 2), and likely was placed under this name depressed rim along the posterior margin of the inner surface of by a past curator when organizing Friese’s collection following its the hind tibia suggest a species of Plebeia. It differs from Plebeia incorporation to the ZMB. Indeed, under the name “nigrifacies”, by a larger body size, wider distance between the clypeus and referring to a stingless bee, a drawer label and catalog card have the eye, coarser punctures on the head and mesosoma, a shorter, been made only for the African taxon in the ZMB collection, convex scutellum, a higher number of hamuli, and by an elon- with the older name from South America being completely gate metasoma, with an unusually long first tergum. While these ignored. Of course, the peculiar features of this species do not features suggest Mourella and Schwarziana, Plectoplebeia lacks suggest other better known groups of the Neotropical region and the long plumose body pilosity, the plumose sternal fimbria, could easily mislead someone when doing a quick inspection. and the modified hind tibia characteristic of these two genera. A new label indicating the type status was added, as well as a Unique features of Plectoplebeia include a shallow depression barcode label currently used in the ZMB for digitalization of the on the lower portion of the frons, the very short scutellum, the collection (Fig. 1). The specimen has also been moved to a new elongate propodeum and metapostnotum, the rectangular first position within the drawer. segment of the metasoma, the elongate and sinuous hindtibia, As established below, Trigona (Plebeia) intermedia, a name and the long wings. proposed by WILLE (1960) for three workers from Bolivia, is The type species of Plectoplebeia, Trigona nigrifacies, has had considered a junior synonym of Friese’s Trigona nigrifacies. This a brief, but convoluted taxonomic history. It was described by synonymy is based on direct comparisons between type speci- FRIESE (1900) from a single worker collected in Peru (“Callanga”). mens, here illustrated in Figs. 3-11. Friese refers it to Schwarziana quadripunctata (Lepeletier, 1836), Description. Worker. a) Body length about 5.5 to 6.0 mm. an indication that could have hinted on the identity of the b) integument between punctures mostly smooth and shiny, taxon, but the brief and limited original description was not of fine rugulosity present on parts of head and mesosoma; meta- much help in the subsequent recognition of the species. The postnotum with fine transverse rugulosity along basal portion taxon remained completely ignored for more than a century and on middle of dorsal area, remainder finely areolate to until its mention in CAMARGO & PEDRO (2007). Based on personal reticulate. c) Body dark brown to black except for vestiture and communication by Claus Rasmussen, who examined the type markings described below; mesoscutum black; wing membrane specimen (Fig. 1), CAMARGO & PEDRO (2007: 572) attributed it to light brown infumated. d) Yellow markings obscured on head, Plebeina Moure, 1961, a stingless bee genus from the Afrotropical with most of mandible, broad stripe on mid of clypeus, lower region, and excluded the taxon from the Neotropical fauna. parocular area and supraclypeal area dark reddish brown; on Indeed, the type specimen bears a label from C. Eardley, dated mesosoma, yellow markings as follows: a transverse stripe on from 2003, as “Plebenia [sic] denoiti (Vachal)” (Fig. 1). Despite pronotum, a spot on the pronotal lobe, one stripe on each 1 2 Figures 1-2. Plectoplebeia nigrifacies: (1) labels of the holotype of Trigona nigrifacies Friese, 1900; (2) place under which the holotype of T. nigrifacies was found in the ZMB collection. 2 / 8 ZOOLOGIA 33(1): e20150153 | DOI: 10.1590/S1984-4689zool-20150153 Plectoplebeia, a new Neotropical genus of stingless