Two new species of Paratrigona and the male of Paratrigona ornaticeps (Hymenoptera, Apidae)

Abstract Two distinctive new species of the Neotropical stingless bee genus Paratrigona Schwarz from Ecuador and Paraguay are described and figured. The Ecuadorian species, Paratrigona scapisetosa sp. n.,belongs to the haeckeli-lineatifrons group and is easily distinguished from its congeners by the unique shape and pubescence of the antennal scape, which is distinctly convex on its outer margin and bears thick, long, simple hairs along its inner margin. The Paraguayan species, Paratrigona wasbaueri sp. n.,belongs to the lineata group and is easily distinguished by the pattern of body pubescence in both sexes and male genitalic characters. The male of the Mesoamerican species Paratrigona ornaticeps (Schwarz) is described and figured. New geographical records for Paratrigona impunctata and Paratrigona opaca, and an updated key to the haeckeli-lineatifrons and lineata species groups are provided.


Introduction
Stingless honey bees (Meliponini) are among the most commonly encountered bees in the tropics of the world. In the Americas, they are found from Mexico to with a dull, dark brown to black integument and conspicuous, contrasting maculae on the head and mesosoma. There are 32 currently recognized species ranging from Mexico to southern Brazil, most of them known from the worker caste (Table 2). Although Meliponini taxonomy is based on workers, the study of the nesting behavior, males, and queens may provide additional characters useful in recognizing cryptic species and in phylogenetic analyses. Unfortunately, the nest and the male of Paratrigona are known for less than half of the species while the queen is only known for two species (Schwarz 1948;Camargo and Moure 1994;Nates-Parra et al. 1999;Fernández et al. 2010).  Michener (2007) except by those taxa he placed as subgenera of Trigona and Plebeia which are herein recognized at the generic level. The distribution and approximate number of species are based on Michener (2007), Camargo and Pedro (2008), and Ascher and Pickering (2011). NA = North America; CA = Central America; SA = South America; † = Extinct, Miocene Dominican and Chiapas amber; ‡ = Extinct, Mesozoic New Jersey amber; * = one species is from Chiapas amber.

Material and methods
Morphological terminology follows that of Michener (2007), while the format for the descriptions generally follows that used by Gonzalez and Vélez (2007) Diagnosis. This species belongs to the haeckeli-lineatifrons species group sensu Camargo and Moure (1994) recognized by the anterior margin of scutum rounded and the presence of maculations on frons, gena, mese-and metepisternum. It is most similar to P. haeckeli (Friese) sharing the maculations on face, thick antennal scape (1.4-1.5 times width of third flagellomere), and body predominantly ferruginous. It can be easily distinguished from that species and any other species of the genus by the distinctive shape and pubescence of the antennal scape. In P. scapisetosa the scape is distinctly convex on its outer margin, abruptly narrowed on basal one-fourth, and bears long (0.5 times width of third flagellomere), stiff, erect, simple hairs along its inner margin (Fig. 4). In P. haeckeli the scape is gently convex on its inner margin, straight or nearly so on its outer margin, and lacks long hairs (Fig. 5). Also, P. scapisetosa differs from P. haeckeli in the preoccipital margin laterally with few stiff, erect simple hairs as those on scape, and the propodeum yellow laterally (Fig. 1).
Description. Worker: Total body length 4.3 mm; head width 1.7 mm; forewing length 3.5 mm. Head slightly wider than long; inner orbits of compound eyes converging below (Fig. 3); malar area subequal to width of third flagellomere; clypeus about twice as broad as long; interalveolar distance equal to median ocellar diameter, shorter (0.8x) than alveolar diameter; alveolocular distance 1.7 times alveolar diameter, 2.1 times interalveolar distance; interocellar distance about two times median ocellar diameter, 1.2 times longer than ocellocular distance; ocelloccipital distance about 1.3 times median ocellar diameter; scape 3.3 times longer than wide, 1.5 times broader than width of third flagellomere, distinctly convex on outer margin, abruptly narrowed on basal one-fourth; pedicel about as long as broad, slightly shorter than first flagellomere; flagellomeres slightly broader than long, except apical flagellomere much longer than broad (Fig. 4); compound eye 2.7 times longer than broad; gena 0.7 times narrower than compound eye in profile. Scutum with anterior margin rounded, 1.2 times broader than long, about twice as long as scutellum; scutellum 1.4 times broader than long, narrowly rounded on distal margin (long-paraboloid sensu Camargo and Moure 1994); hind tibia 2.6 times longer than broad; hind basitarsus about twice as long as broad, strongly projecting on posterodistal margin. Integument in general finely and densely punctate, dull, as in other species of the genus; propodeum without impunctate midline.
Color predominantly ferruginous, except: black on upper two-thirds of frons, apex of scape, pedicel, flagellum; dark reddish brown on subantennal area, epistomal sulcus, malar area, mandible distally (darker on teeth), mesepisternum ventrally, hind tibia distally, outer surfaces of middle and hind basitarsi; yellow maculations as follows: mandible basally, labrum, scape, face (Fig. 3), gena and vertex with complete, thin band (at most as wide as median ocellar diameter), pronotum, pronotal lobe, anterior one-third of tegula, costal sclerite, mesepisternum laterally, metepisternum entirely, propodeum laterally, scutum laterally with broad band (as wide as median ocellar diameter), axilla, lateral and distal margins of scutellum with narrower band than on scutum, apices of middle and hind femora, outer surfaces of fore and middle tibiae with narrow band, hind tibia with band on posterior margin, fore and middle basitarsi basally. Wing membrane subhyaline with weak greenish and coppery reflections; veins and stigma dark brown (Figs 1, 2).
Body sparsely covered with minute, appressed, simple yellowish to whitish hairs except as follows: inferior margin of mandible, labrum, and hypostomal area with long (about as long as median ocellar diameter), erect hairs; scape with stiff, erect, simple hairs (0.5 times width of third flagellomere) along inner margin (Fig. 4); gena laterally with few stiff, erect hairs as those on scape; mesepisternum ventrally, middle and hind coxae, sterna with much longer, erect simple hairs (about twice as long as median ocellar diameter); sides of propodeum with dense, branched, semierect hairs (0.5 times median ocellar diameter) partially obscuring integument.
Male: Unknown. Queen: Unknown. Etymology. The specific epithet is a combination of the Latin words "scāpus" and "saetae", in reference to the distinctly long hairs along the inner margin of the antennal scape.
Comments. An additional female specimen of P. scapisetosa from Sierra de Chiribiquete in Colombia (Department of Caquetá) has been examined by one of us (VHG) but it was not available for study. The propodeum laterally with yellow maculations of P. scapisetosa is a character only shared with P. ornaticeps.
Paratypes. 54♀, 28♂, with same data as holotype but collected on November 24-30, and December 1-4 (BBSL, DZUP, SEMC). Camargo and Moure (1994) recognized by the anterior margin of scutum rounded and the absence of maculations on frons, gena, mese-and metepisternum . It is most similar to P. lineata (Friese) sharing the narrow antennal scape (narrower than width of third flagellomere), and the presence of hairs on the disc of scutellum distally and mesepisternum dorsally (Figs 9, 10). It can be easily distinguished from that species by the absence of hairs on the disc of the scutum in both sexes and the digitiform basal projection of the penis valve in the male (Figs 18, 19). The new species also resembles P. glabella Camargo & Moure and P. incerta Camargo & Moure in the absence of erect hairs on the scutum; however, in those species the mesepisternum lacks erect hairs dorsally and the erect hairs of the scutellum are either short (at most half median ocellar diameter) or restricted to its distal margin or inferior surface. Also, the basal projection of the penis valve of the male is short and pointed in P. glabella (male of P. incerta unknown), not digitiform as in P. wasbaueri (cf., Camargo and Moure 1994;fig 143). Description. Worker: Total body length 4.2 mm (3.8-5.2 mm); head width 1.6 mm (1.6-1.7 mm); forewing length 3.6 mm (3.6-3.8 mm). Head slightly wider than long; inner orbits of compound eyes converging below (Fig. 8); malar area about half width of third flagellomere; clypeus 1.8 times broader than long; interalveolar distance 1.2 times median ocellar diameter, about equal to alveolar diameter; alveolocular distance 1.3 times alveolar diameter; interocellar distance 2.1 times median ocellar diameter, 1.8 times longer than ocellocular distance; ocelloccipital distance about 1.3 times median ocellar diameter; scape 6.3 times longer than wide, narrower (0.8 times) than width of third flagellomere; pedicel about as long as broad, slightly shorter than first flagellomere; flagellomeres slightly broader than long, except apical flagellomere much longer than broad; compound eye 2.8 times longer than broad; gena 0.8 times narrower than compound eye in profile. Scutum with anterior margin rounded, slightly broader than long, 2.8 times longer than scutellum; scutellum about twice as long as broad, broadly rounded on distal margin (short-semicircular sensu Camargo and Moure 1994); hind tibia 2.6 times longer than broad; hind basitarsus about twice as long as broad, strongly projecting on posterodistal margin.

Diagnosis. This species belongs to the lineata species group sensu
Integument in general finely and densely punctate, dull, as in other species of the genus; propodeum without impunctate midline.
Body sparsely covered with minute, appressed, simple whitish hairs except as follows: inferior margin of mandible, labrum, vertex, hypostomal area, mesepisternum dorsally, distal margin of scutellum dorsally and ventrally, sides of propodeum with long (about as long as median ocellar diameter) erect hairs; mesepisternum ventrally, middle and hind coxae, sterna with much longer, erect simple hairs (about twice as long as median ocellar diameter); sides of propodeum with dense, branched, semierect hairs (0.5 times median ocellar diameter) partially obscuring integument; inner surface of tarsi with yellowish to ferruginous hairs.
Male: As in female except for longer body pubescence, brownish legs, and the following: Total body length 4.4-5.3 mm; head width 1.6 -1.7 mm; forewing length 3.7-3.8 mm. Inner orbits of compound eyes strongly converging below (Fig.  12); malar area linear; clypeus 1.3 times broader than long; interalveolar distance subequal to median ocellar and alveolar diameters individually; alveolocular distance about as long as alveolar diameter; interocellar distance about twice median ocellar diameter, 2.8 times longer than ocellocular distance; ocelloccipital distance about 0.7 times median ocellar diameter; scape 3.6 times longer than wide, slightly narrower than width of third flagellomere; pedicel longer than first flagellomere; first flagellomere about twice as broad as long, 0.5 times shorter than second flagellomere; gena about half width of compound eye in profile. Hind tibia about 3 times longer than broad; hind basitarsus 3 times longer than broad. Genitalia and associated sterna as in Figs 13-19.
Queen: Unknown. Etymology. The specific epithet is a patronym honoring Marius Wasbauer, friend and colleague, who has contributed much of the material we have studied, including the species described in this paper.

Paratrigona ornaticeps
Trigona (Paratrigona) opaca ornaticeps Schwarz, 1938 Diagnosis. The female of this species can be separated from other species of the haeckeli-lineatifrons group by the following combination of characters: frons with broad and long inverted Y-shaped maculation; paraocular area with complete, long, broad maculation; supraclypeus yellow; and clypeus with broad, inverted T-shaped maculation (cf., Camargo and Moure 1994; fig 115). Paratrigona ornaticeps can be confused with P. uwa Gonzalez & Vélez and P. compsa Camargo & Moure by the shape of the facial maculations but in those species they are much narrower and the metasoma is ferruginous (cf., Camargo and Moure 1994;fig 118;Gonzalez and Vélez 2007; fig 1).
The male of P. ornaticeps can be separated from that of P. haeckeli, the only other male known of the haeckeli-lineatifrons group (Table 2), by the sixth sternum, which has a broader midapical projection, and the shape of the gonostylus, which is more strongly curved apically in profile (compare Figs 26 and 27 with Camargo and Moure 1994;figs 130, 132).
Description. Male: Total body length 4.7-5.1 mm; head width 1.6 -1.7 mm; forewing length 3.7-3.8 mm. Head slightly wider than long; inner orbits of compound eyes strongly converging below (Fig. 21); malar area very short, about onefourth width of third flagellomere; clypeus 1.5 times broader than long; interalveolar distance slightly shorter (0.9x) than median ocellar and alveolar diameters individually; alveolocular distance 1.3 times alveolar diameter, 1.2 times interalveolar distance; interocellar distance 1.5 times median ocellar diameter, 2.7 times longer than ocellocular distance; ocelloccipital distance about 0.7 times median ocellar diameter; scape 2.8 times longer than wide, slightly broader than width of third flagellomere; pedicel about as long as broad, slightly longer than first flagellomere; first flagellomere 1.5 times broader than long, 0.7 shorter than second flagellomere, remaining flagellomeres slightly broader than long, except apical flagellomere much longer than broad; compound eye 2.6 times longer than broad; gena about half width of compound eye in profile. Scutum with anterior margin rounded, 1.1 times broader than long, 2.3 times longer than scutellum; scutellum 1.5 times broader than long, broadly rounded on distal margin (long-paraboloid sensu Camargo and Moure 1994); hind tibia about 3 times longer than broad; hind basitarsus 2.6 times longer than broad. Genitalia and associated sterna as in Figs 22-27.
Integument in general finely and densely punctate, dull, as in other species of the genus; propodeum with faint midline.
Color predominantly black, except: brownish on anterior surface of flagellum, tegula, legs (legs light yellow to ferruginous with pale maculations); yellow maculations as follows: mandible, labrum, anterior surface of scape, face as in Fig. 21 (frons sometimes maculate along middle line, never with inverted broad Y-shaped maculation as in fe- male), gena basally with thin band (less than half median ocellar diameter), vertex with small spot laterally, pronotum, pronotal lobe, tegula with small spot on anterior half, costal sclerite, mesepisternum laterally with spots, metepisternum almost entirely, scutum laterally with broad band (about half median ocellar diameter), axilla, lateral and distal margins of scutellum with narrower band than on scutum, apices of middle and hind femora, outer surfaces of fore and middle tibiae with narrow band, hind tibia with band on posterior margin, fore and middle basitarsi basally. Wing membrane subhyaline with weak greenish and coppery reflections; veins and stigma dark brown (Fig. 20).
Body sparsely covered with minute, appressed, simple yellowish to whitish hairs except as follows: vertex, hypostomal area, middle trochanter with long (about half median ocellar diameter), erect hairs; hind coxa, seventh tergum with much longer erect hairs (at least as long as median ocellar diameter); sides of propodeum with dense, branched, semierect hairs (about 0.5 times median ocellar diameter) partially obscuring integument. Comments. These new records expand the distribution of this species from its previously known range: Brazil, Colombia, French Guiana, Guyana, Peru, and Suriname (Table 2).

Key to species of the haeckeli-lineatifrons and lineata species groups of
P. opaca (Cockerell, 1917) ♀♂ F Colombia, Costa Rica, Ecuador, Guatemala, Mexico, Panama P. pacifica (Schwarz, 1943) ♀♂ ‡ A Bolivia, Brazil, Colombia, Ecuador, Peru P. pannosa Moure, 1989 ♀  (9) Scape distinctly convex on its outer margin, abruptly narrowed on basal onefourth, inner margin straight or nearly so, with long (0.5 times width of third flagellomere), stiff, erect, simple hairs (Fig. 4)  Scape straight or nearly so on its outer margin, not abruptly narrowed on basal one-fourth, inner margin gently convex, without long hairs (Fig. 5) (11) Maculations absent or reduced on inferior paraocular area and clypeus; paraocular band present above superior tangent of antennal alveolus; frontal maculation separated in two small spots, one below median ocellus, the other in the middle of frons; mesepisternum dorsally with spot as large as that on pronotal lobe; malar area short, slightly longer than half width of third