Taxonomic revision of Parasarus ( Hymenoptera : Apidae s . l . : Protandrenini ) , a South American genus of bees

Parasarus Ruz, 1993 comprises small black bees (3-5 mm long) endemic to xeric regions of South America, mainly along of the Andean Cordillera. Prior to this study, the genus included only the type-species P. atacamensis Ruz, 1993 (from northern Chile) which has mesoscutum strongly reticulated and inner hind tibial spur curved apically. In this paper, a taxonomic revision of Parasarus is presented and two new species are described: P. specularis sp. nov. (from central to northwest Argentina) diagnosed mainly by pygidial plate of female extremely acute apically and labral plate yellow in male; and P. spiniventris sp. nov. (only recorded from central portion of Chile) diagnosed by antennal socket below middle of face, subantennal area as long as broad, metapostnotum smooth, and sternum 3 of male with a tuft of stiff hairs. The morphological variation related to the type-species was studied and not considered sufficiently to recognized distinct species into P. atacamensis. Distribution maps, floral associations, key to species of the genus, and illustrations of general external morphology and genitalia are also provided.

Protandrenini is the most diverse group of Andreninae bees (Hymenoptera: Apidae s.l.) in the Neotropical region by number of genera with more than 400 species described (MOURE et al. 2012, ASCHER & PICKERING 2014).The tribe is restricted to the Americas, being diverse in temperate and xeric areas (MICHENER 2007).Among Protandrenini genera of South America, Parasarus Ruz, 1993 comprises small black bees (3-5 mm long) endemic to xeric regions of Argentina and Chile (RUZ & ROZEN 1993, MICHENER 2007).Parasarus was proposed by RUZ (in RUZ & ROZEN 1993) for a single species -P.atacamensis Ruz, 1993.Nests of this species are built in soil and shared by a number of females, and parasitized by bees of the genus Kelita Sandhouse, 1943 (Apidae: Nomadini) (RUZ & ROZEN 1993).Species of Parasarus can be collected from September to February and are apparently polylectic in relation to floral hosts.Males fly actively around flowers near nesting sites, searching for mates (RUZ & ROZEN 1993).Although the mature larvae exhibit unique features (such as a globose antennal prominence and minute spiracles), they generally resemble other Protandrenini larvae in having dorsal thoracic tubercles, well-developed maxillae, large maxillary palpi, and strongly recessed labial region (RUZ & ROZEN 1993).
Parasarus remained monotypic until the present study, although RUZ & ROZEN (1993) mentioned the existence of additional undescribed species from Chile and Argentina, and called attention to morphological variability observed among populations of P. atacamensis.In this paper, a taxonomic revision of Parasarus is presented with description of two new species and the study of morphological variation related to the type-species.Floral associations, distribution map, illustrations, and a key to species are also provided.
General morphological terminology follows URBAN (1967) and MICHENER (2007); labral plate is characterized by an elevated and glabrous area in the central portion of the labrum; antennal flagellomeres are indicated as F1-F11, and metasomal terga and sterna as T1-T7 and S1-S8, respectively.The antennal flagellomeres and labial palpomeres were numbered from the base to the apex.The density of punctation refers to the relative puncture diameter, pd (e.g., <2 pd: less than 2x the puncture diameter between punctures).All measurements are given in millimeters.
The labels of the specimens examined are exactly transcribed in the sections Type material and Additional material, where one inverted bar (\) indicates different lines on the label and quotation marks (") indicate different labels of the same specimen.Photographs were taken with a Leica video camera (DFC 295) attached to a Leica stereomicroscope (M205C).Series of images were combined in the software LEICA LAS (Leica Application Suite V3.6.0) and CombineZP to produce confo- Diagnosis.The diagnostic characters presented by RUZ & ROZEN (1993) and MICHENER (2000MICHENER ( , 2007) ) that are common to all species of Parasarus here recognized are the following: small body size (3-5 mm); integument predominantly black or dark brown with some yellow markings on legs; pubescence in general short and white; face without yellow marks in either sex; glossa shorter than prementum; segment 1 of labial palpus with similar length or shorter than segments 2-4 combined; lower half of face of males densely pilose; anterior tentorial pit at intersection between outer subantennal and epistomal sutures; supraclypeal area weakly produced between antennal sockets; mesosoma sparsely punctate; submarginal cells two; outer margin of hind tibia of males toothed; mid tibial spur of females finely serrate; metasoma of males broader than mesosoma; lateral foveae of T2 weakly depressed; T7 of male without pygidial plate (Fig. 29); S8 of male gradually tapering to a distal projection (Figs 31,34,and 37); volsellae with denticles; gonostyli of male less than half length of gonocoxites .However, two additional characters cited by RUZ (in RUZ & ROZEN 1993) as diagnostic for Parasarus were not found in all species recognized here: the hind tibial spurs strongly curved, only observed in females of P. atacamensis and P. specularis sp.nov., and males of P. atacamensis (inner spur); and the small tubercle between antennal sockets of males, exclusively found in P. atacamensis and its presence is variable among individuals.Additional features observed that complement the recognition of this genus are: antennal flagel-lum of males as long as maximum head width (similar to females); pronotal lobe almost black in both sexes; metapostnotum slightly depressed with some minute hairs laterally ; lateral line of T1 evident; metasomal terga of males with postgradular area weakly depressed (Fig. 28); S8 of males with enlarged disc (Figs 31,34,and 37); volsella with short cuspis; gonostylus with sparse pilosity (Figs 39-47); penis valve acute distally and fused basally.
Remarks.The phylogenetic relationships among genera of Protandrenini are poorly understood and the current generic classification is not consensual.Parasarus was recognized as a subgenus of the North American genus Protandrena Cockerel, 1896 by MICHENER (2000MICHENER ( , 2007)).However, morphological and molecular phylogenetic analyses provided substantial support for recognizing Parasarus as a phylogenetic independent lineage from Protandrena (J.S. Ascher, unpubl.data, K.S. Ramos, unpubl. data).Parasarus differs from Protandrena s.s.mainly in having integument with shallow and sparse punctures, face without yellow marks, mid tibial spur of females finely serrate, metasoma of males broader than mesosoma, metasomal terga without basal hair bands, postgradular area of metasomal terga of males weakly depressed, and S8 of males with broad disc (not constricted in the middle).Males of Parasarus exhibit intraspecific variation in the width of head, which may vary from narrower to broader than mesosoma.These wide-headed males look like those of the genus Cephalurgus Moure & Lucas de Oliveira, 1962, but they differ principally by the lateral foveae of T2 weakly depressed, supraclypeal area slightly produced, genital capsule without basal sclerite, and gonocoxite without an oblique lateral impression (Figs 39-47).
Variation.As mentioned above, males of Parasarus show variation in head width.In comparison to males with small head, wide-headed specimens have more sparsely distributed punctures and hairs, distinctly longer mandibles, vertex more swollen above ocelli, and gena broader than compound eyes (Figs 5 and 6).
Distribution.Species of Parasarus are restricted to xeric regions of South America, occurring from lowlands to high mountains (above 4000 m) of northern Chile to southern Argentina, mainly along both sides of the Andean Cordillera (Fig. 48).According to the biogeographical classification of Latin America (see MORRONE 2006, 2014, FERRO & MORRONE 2014), the genus is distributed essentially in the Andean region and South American transition zone.Parasarus atacamensis occurs mainly in the Central Chilean sub-region (Andean region) from Alto Patache (Tarapacá, Chile) to Caleu (Región Metropolitana, Chile), the first being the northernmost distribution record for the genus, with few records from the South American transition zone.Parasarus specularis sp.nov. is widely distributed in the South American transition zone from Salta to Río Negro (Argentina), the latter being the southernmost distribution record for the genus, with scarce records from the Neotropical region (Córdoba, Argentina).Parasarus spiniventris sp.nov. is only known from Central Chilean sub-region (Andean region).
Variation.This species shows a remarkable variation in overall body size and integumental surface in both sexes.In particular, the first labial palpus vary in length from similar to shorter than segments 2-4 combined, and the small tubercle between antennal sockets is absent in many individuals, a variation not correlated with distribution.Specimens from Tarapacá province (Tarapacá region) are small (approximately 3 mm), and show strongly reticulated integument between punctures.Males from Diego de Almagro (Atacama) differ in having a yellow labral plate, and females are more robust and shiny, with slightly longer proboscis than specimens from the type locality (Paipote, Atacama region).Females from the Metropolitan region of Santiago have a narrow lateral fovea of T2 in comparison to P. atacamensis found in Northern Chile.In spite of this, the variation reported is not considered consistent as to split P. atacamensis into two or more unequivocal, morphologically distinct species.Further integrative approaches using other data sources (e.g., nucleotide sequences) will help investigate whether morphological variation reflects divergent lineages (cryptic species) of P. atacamensis.13) head of male in frontal view (holotype); ( 14) habitus of male (holotype).Scale bar: 1 mm.
Diagnosis.This species can be easily distinguished from the other species of Parasarus by the following combination of characters: integument smooth and shiny between punctures (especially on clypeus, supraclypeal area, and mesoscutum) 16,and 19); labral plate and distal margin of clypeus yellow in male (Fig. 9); clypeus of female with median longitudinal groove; lower portion of face of female with sparse hairs; ventral portion of mesepisternum of female with curved hairs apically; apex of hind tibial spurs curved apically in female and straight in male; mid tibial spur as long as mid basitarsus.Additionally, males of P. specularis sp.nov.have distinctive morphology of genitalia and hidden sterna, mainly by lobes of S7 retrorse and enlarged apically with coarse hairs (Fig. 33), S7 with relatively less constriction at base (Fig. 33), and S8 with acute projection on basolateral apodeme (Figs 34 and 35).
Variation.The yellow distal margin of male clypeus can be completely absent or very conspicuous.Although this new species is distributed in distinct altitudinal ranges, individuals from lowland and high altitude do not present morphological variation.

Taxonomic revision of Parasarus (Hymenoptera: Apidae s.l.: Protandrenini), a South American genus of bees Kelli dos Santos Ramos
Parasarus Ruz, 1993comprises small black bees (3-5 mm long) endemic to xeric regions of South America, mainly along of the Andean Cordillera.Prior to this study, the genus included only the type-species P. atacamensisRuz,   1993(from northern Chile) which has mesoscutum strongly reticulated and inner hind tibial spur curved apically.In this paper, a taxonomic revision of Parasarus is presented and two new species are described: P. specularis sp.nov.(from central to northwest Argentina) diagnosed mainly by pygidial plate of female extremely acute apically and labral plate images.Male genitalia and associated sterna were detached from the metasoma, cleared in a 10% KOH solution for 16h, neutralized in acetic acid, and stored in a vial with glycerin.