Centris atra Friese, 2017

Vivallo, Felipe, 2018, Taxonomic note on the type species of Centris (Melanocentris) (Hymenoptera: Apidae), Journal of Melittology 2018 (77), pp. 1-6 : 3-5

Centris atra Friese

( Figs. 1–3 )

Centris atra Friese, 1899: 41 .

TYPE MATERIAL: Lectotype ♀, here designated with the following data label: Brasil Blumenau 1897 Virgil \ Centris atra n.sp. det. Friese, 1898 ♀ \ Lectotype Centris atra Friese, 1899 Des. F. Vivallo, 2017 ( NMW) ( Fig. 4 ) . Paralectotypes: 1♀, Brasil Blumenau 1897 Virgil \ Centris atra type! Fr . ♀ 1900 Friese , det. ( HNHM) ; 1♀, Columbien \ 19761\ Centris atra ♀ det. Friese 1898 ( ZMB) ; 1♀, [indecipherable handwriting]\ Centris atra n.sp. det. Friese 1898 ( NMW) .

Moure et al. (2007) mentioned São Paulo ( Brazil) as one of the type localities, but that information does not agree with that provided in the original description of the species ( Friese, 1899).

In order to facilitate the recognition of C. atra , a redescription of the species based on the lectotype is presented here, following the morphological terminology used by Vivallo (2016) and as originally proposed by Michener (2007) and Neff & Simpson (1981). The abbreviations T and S are used for metasomal terga and sterna, respectively. The morphological structures and the characters of coloration and surface sculpture mentioned below are those useful to identify this species and that vary between the species of Melanocentris .

DIAGNOSIS: This species can be recognized by the following combination of characters: Integument dark brown to black ( Figs. 1‒2 ). Labrum with punctation denser towards the basal margin and on middle longitudinal line. Basitibial plates slightly lanceolate ( Fig. 3 ). Fore elaiospathe with anterior secondary comb formed by five giant, apically curved setae.

DESCRIPTION: ♀: Measurements (mm). Total approximate length: 20.4. Head width: 6.47. Forewing length: 17.2. Coloration. Integument dark brown to black ( Figs. 1‒3 ). Distal margins of terga and sterna, except T 6 and S6, dark brown, slightly translucent. Wings dark brown with greenish iridescence. Sculpture. Clypeus finely areolate with coarse and fine punctation intermixed, denser towards sides; central longitudinal surface only with fine and very scatered punctures and very narrow, impunctate, longitudinal, slightly raised line not reaching epistomal sulcus. Labrum with coarse and fine punctation intermixed, denser towards basal margin and on middle longitudinal line. Metasomal terga finely areolate, with fine and dense punctation, coarser towards apex of metasoma, all terga except T 6 with smooth distal margins. Pubescence. Dark brown to blackish ( Figs. 1, 2 ). T 1 and anterior surface of T 2 with plumose hairs, T 3– T 6 with mostly simple and short pubescence, with some long hairs intermixed, longer on T 4 and T 5. Structure. Flabellum circular, slightly projected forward. Maxillary palpus with four palpomeres (relative lengths: 2 nd>3 rd>1 st>4 th). Mandible strongly curved apically with four teeth each with acute apex, except fourth truncate and broader than others. Clypeus convex, slightly flat on lower half (lateral view), lower margin concave (frontal view). Labrum triangular with rounded apex. Vertex above upper interorbital tangent ( Fig. 1 ). Inner orbits of compound eyes relatively parallel ( Fig. 1 ). Fore elaiospathe with anterior secondary comb formed by five giant apically curved setae. Mesoscutellum with two poorly developed protuberances. Basitibial plate elliptical, slightly lanceolate ( Fig. 3 ). Secondary plate projected backwards ( Fig. 3 ). Pygidial plate with truncate apex and secondary plate. Pretarsal claws with preapical tooth, except hind leg.

COMMENTS: The information of the labels on locality and collector of the specimen here designated as lectotype corresponds exactly to that cited by Friese (1899). In 1901, this author published additional information on the morphology of this species, along with doubtful distribution records taken from a miscellaneous series of misidentified specimens. In that article ( Friese, 1901), the year of the collection of the specimens from Blumenau (1898) differs from that contained on the label (1897). The Brazilian specimens, as well as the one from Colombia cited above, agree with the original description, and are superficially similar to each other, all belonging to the same subgenus. Morphological characteristics shared by these females include the shape of the mandibles, and the basitibial and pygidial plates. This would imply no difference in the higher level classification if the Colombian syntype had been chosen as the lectotype. As mentioned above, even though Friese (1899) cited five specimens forming the type series, only four of them were found. The depository and the current condition of the missing syntype remain unknown.

It is not clear how and when the specimens from Blumenau were deposited at NMW and HNHM. According to Rasmussen & Ascher (2008) there are other primary types of bees described by Friese in these institutions .

The identity of the specimen from Colombia is unclear. There are some undescribed species from northern South America that look superficially similar to C. atra , so that specimen could belong to one of them or to an already described species such as C. braccata or C. xylocopoides whose type specimens have not yet been studied in detail.

The motive that led Moure (1995) to identify the specimen housed at NMW as a melanic form of C. dorsata and not as one of the syntypes of C. atra is unknown. Both species have different morphological characteristics, like the apex of the fourth mandibular tooth (truncated in C. atra and concave in C. dorsata ), the pubescence on the mesoscutum (dark brown to black in C. atra and yellowish in C. dorsata ) and on T 5 (blackish in C. atra and yellowish in C. dorsata ), the coloration of T 6 (dark brown to black in C. atra and yellowish in C. dorsata ), the areolation of the clypeal disc (present in C. atra and absent in C. dorsata ), the shape of the lower margin of the secondary basitibial plate (slightly angulate in C. atra and convex in C. dorsata ), and the punctation patern on the labrum (denser on basal margin and on central longitudinal area in C. atra and uniformly distributed in C. dorsata ). All of these characters make both species unmistakable. On the other hand, the recognition of C. atra as a member of Ptilotopus was probably due to the erroneous interpretation of the information cited by Friese (1899, 1901) concerning the two protuberances on the mesoscutellum. The presence of protuberances is not exclusive to Ptilotopus , but is also observed in species of other subgenera, although with different shapes and sizes.

The presence of a secondary basitibial plate ( Fig. 3 ), the lack of a strong tubercle on the anterior lower part of the hypoepimeral area, and the absence of well-defined glabrous areas on the mesoscutum and mesoscutellum indicate that C. atra does not belong to the subgenus Ptilotopus , but to Melacentris sensu Moure (1995) . By designating this species as the type of Melanocentris , Sandhouse’s (1943) decision requires that this name be revalidated, withdrawing it from synonymy of Ptilotopus and maintaining its traditional conception. Consequently, Melacentris is proposed as a new junior synonym of Melanocentris .

Figures

Figures 1–4. Lectotype female of Centris atra Friese. 1. Head, frontal view (scale bar = 2 mm). 2. Habitus, lateral view (scale bar = 5 mm). 3. Basitibial plates (scale bar = 0.6 mm). 4. Labels of lectotype designated herein.