Xeranthrena imponticula Gonzalez and Engel, 2017

Gonzalez, Victor H., Smith-Pardo, Allan H. & Engel, Michael S., 2017, Phylogenetic Relationships Of A New Genus Of Calliopsine Bees From Peru, With A Review Of Spinoliella Ashmead (Hymenoptera: Andrenidae), Bulletin of the American Museum of Natural History 2017 (412), pp. 1-72 : 18-20

Xeranthrena imponticula Gonzalez and Engel ,

new species

Figures 2 , 3

DIAGNOSIS: In addition to the generic characters indicated above, this species can be recognized by the simple, not bifid, pygidial plate. In this latter regard, the female is superficially similar to S. obscura , a species that also shares with X. imponticula a straight outer metatibial spur. Xeranthrena imponticula can be further separated from S. obscura and other species of Spinoliella by the following combination of characters: larger body size (7–10 mm); frons, mesoscutum, mesoscutellum, and discs of terga smooth and shiny, uniformly punctate (e.g., fig. 2E), with punctures separated by a puncture width or less; propodeum dull, densely and contiguously punctate; forewing with pterostigma with sides diverging distally and with the margin within the marginal cell convex; male S2–S5 with discs densely covered by short, appressed setae as those on tergal discs, without distinct band of long, erect setae; and shape of male S7, S8, and genital capsule (fig. 3F–I).

DESCRIPTION: Female. Total body length 8.7 mm (7.3–8.7 mm); forewing length 5.3 mm (4.6– 5.3 mm); head width 2.5 mm (2.1–2.5 mm). Head 1.3× wider than long; inner orbits of compound eyes parallel; intertorular distance about 3× OD, 1.4× greater than torulorbital distance; torulus diameter about equal to OD; ocellocular distance 2.6× OD, 1.2× greater than ocelloccipital distance; interocellar distance 2.4× OD, slightly shorter (0.9×) than ocellocular distance; compound eye 2.2× longer than wide; clypeus 3.2× broader than long, preapically slightly depressed on disc, with apex surpassing inferior tangent of compound eyes by about half of its length, pro- jected about 0.5× compound eye width in lateral view; gena 0.9× width of compound eye in profile, widest medially; inner subantennal sulcus about 0.7× length of outer subantennal sulcus; facial fovea long, deep, forming a groove, 13× longer than broad, about same width (0.3× width of scape) across its length, 1.1× longer than scape; scape 3.4× longer than broad; pedicel about as long as F1, about as long as broad; F1 slightly longer than broad, 1.5× longer than F2 and F3 individually; remaining flagellomeres broader than long, except last flagellomere longer than broad. Protibial spur with apical portion of rachis about as long as length of malus, with row of 10 elongate branches (not including apical portion of rachis); mesobasitarsus robust, about 2.8× longer than broad; metatibia 4.2× longer than broad; metabasitarsus 5.0× longer than broad, about 0.6× length of metatibia.

Body color black except dark reddish brown on mandible apically, antennal flagellum, legs, and metasoma. Yellow maculation as follows: mandible basally; clypeus laterally and medioapically; supraclypeal area; lower paraocular area including paraclypeal swelling (nearly absent in one paratype); subantennal area; dorsal surface of pronotum laterally; outer surfaces of pro- and mesotibiae basally; T1–T5 each with lateral maculation, gap between maculation narrower on T3 and T4. Tegula semitranslucent brownish; wing membranes brownish with weak green and copper highlights; veins, prestigma, and pterostigma light to dark brown.

Body pubescence whitish except off-white on vertex and metasoma, and light reddish brown on inner surfaces of tarsi. Head and mesosoma with minutely branched setae denser on frons and mesoscutum, integument largely visible among setae; mesoscutum and mesoscutellum with long (1.0–1.5× OD), sparse, erect setae arising among shorter, denser, appressed setae. Metasoma covered by minute, appressed, sparse setae, with semierect, long (1.0–1.5× OD), scattered setae on discs of sterna, sides of terga, and discs of T4 and T5, setae longer and denser on apical terga.

Outer surface of mandible except basally and basal one-third of labrum smooth and shiny, impunctate; clypeus smooth and shiny, with faint punctures separated by 1.0–2.0× a puncture width, punctures smaller and denser laterally; paraclypeal swelling impunctate; subantennal, supraclypeal, and lower paraocular areas smooth and shiny with smaller, fainter punctures than on clypeal disc, punctures separated by 1.0–2.0× a puncture width; remaining areas of face uniformly punctate, punctures coarser and denser than on disc, integument otherwise smooth and shiny; vertex behind ocelli with weakly imbricate integument among oval punctures; gena minutely punctate, punctures denser near orbital margin, scattered, larger on hypostomal area, integument otherwise smooth and shiny. Mesosoma, including legs, smooth and shiny among punctures except strongly imbricate on metepisternum and sides of propodeum, finely alveolate on propodeal triangle, and coarsely alveolate on posterior surface of propodeum; mesoscutum and mesoscutellum densely and uniformly punctate, punctures separated by a puncture width or less; metanotum with denser punctures than on mesoscutellum; mesepisternum with denser, fainter, and larger punctures than on mesoscutum, punctures sparser dorsally. Metasomal terga and sterna uniformly and minutely punctate, weakly imbricate among punctures.

Male. As in female except pubescence slightly longer and denser, and in following features: total body length 7.0‒ 10.1 mm; forewing length 4.6‒5.7 mm; head width 2.2‒2.9 mm. Head 1.3– 1.4× wider than long; mandible arcuate; intertorular distance 2.8× OD, 1.2× greater than torulorbital distance; torulus diameter 0.9× OD; ocellocular distance equal to ocelloccipital distance; clypeus 3.6× broader than long, projected about 0.4× compound eye width in lateral view; gena about as wide as compound eye in profile; facial fovea shallower than in female, 7.0× longer than broad, 0.7× length of scape; scape 3.0× longer than broad; pedicel slightly shorter than F1; F1 1.6× longer than F2 and F3 individually. Metatibia 3.7× longer than broad; metabasitarsus 4.5× longer than broad; mesobasitarsus slender, 5.4× longer than broad. Metasomal S7, S8, and genital capsule as in figure 3F–I.

Body color as in female except yellow on: labrum, clypeus except basally on disc, anterior surface of scape (sometimes reduced) (fig. 3A, C), apices of pro- and mesofemora, and outer surface of protibia (sometimes reduced). Metasomal T1–T5 each with lateral yellow maculation smaller than in female (sometimes reduced to absent on T2) (fig. 3B, D).

HOLOTYPE: ♀, Peru: Lima Dept., 15 km WSW Sayán, V-12-1996 [12 May 1996], J.G. Rozen, A. Ugarte, & M. Laime // On Exodeconus prostratus (AMNH) .

PARATYPES (n = 8♀♀, 10♂♂): PERU: Lima Province: 2♀♀, 1♂ with same data as holotype ( AMNH); 1♀ with same data as holotype but collected on V-11-96 [11 May 1996] ( AMNH); 1♀, 3♂♂, Lima Dept., 15 km WSW Sayan, VI-26–28-95 [26–28 June 1995], J.G. Rozen, A. Ugarte // On Exodeconus maritimus (1♀, 1♂ AMNH, 2♂♂ SEMC); 1♀, same as previous except VI-27-95 [27 June 1995] ( AMNH); La Libertad Province: 1♀, 1♂, La Libertad Dept., La Gloria, 7.5 km, NNW Paiján, V-23-96 [23 May 1996], J.G. Rozen & A. Ugarte // On Exodeconus prostratus (1♂ AMNH, 1♀ SEMC); 1♂, Chile [sic, Peru], La Libertad Pr. 31 km E Trujillo, 21 Mar 1999, J.G. Rozen, A. Ugarte ( AMNH); Ancash Province: 1♀, 1♂, Ancash Prov., 21 km E Casma, 9°28′92″S, 78°06′97″W,el. 2000′ III-20-1999 [20 March 1999] // on plant #5 // J.G. Rozen, A. Ugarte // SEMC 1008502, 1008504 ( SEMC); 1♀, 1♂, same as previous except Yaután, 9°31′69″S, 72°99′22″W, III-20- 1999 [20 March 1999], J.G. Rozen, A. Ugarte // on plant #5 // SEMC 1008501, 1008503 ( SEMC); 2♂♂, same as previous except 9°31′S, 77°99′W, 20 Mar 1999, Rozen, Ugarte ( AMNH).

ETYMOLOGY: The specific epithet is a combination of im- (Latin, “without”) and ponticulus (Latin, diminutive of “bridge”), and is a reference to the lack of a dorsal bridge to the penis valves.

DISTRIBUTION: This species is known only from the xeric areas along the Pacific slope of the Andes in central and northern Peru.

FLORAL ASSOCIATIONS: Exodeconus prostratus (L’Hér.) Raf. and E. maritimus (Benth.) D’Arcy (Solanaceae) .

COMMENTS: The collection locality indicated for one of the male paratypes as “ Chile, La Libertad Pr. 31 km E. Trujillo” is clearly a typographical error because both La Libertad Province and its capital, Trujillo, are in Peru.

Figures

FIGURE 2. Female holotype of Xeranthrena imponticula Gonzalez and Engel, new species. A. Facial view. B. Detail of clypeus. C. Head in lateral view. D. Dorsal habitus. E. Detail of mesoscutum and mesoscutellum in dorsal view. F. Metabasitibial plate. G. Metasoma in dorsal view. H. Lateral habitus. I. Metasomal S6 in ventral view.

FIGURE 3. Male paratype of Xeranthrena imponticula Gonzalez and Engel, new species. A. Facial view. B. Lateral habitus. C. Dorsal habitus. D. Metasoma in dorsal view. E. Metabasitibial plate. F. Metasomal S7. G. Metasomal S8. H. Genital capsule in dorsal (left half) and ventral (right half) views. I. Lateral aspect of genital capsule.