Stilbochlora graceae Engel, 2019

Engel, Michael S., 2019, New species of the augochlorine bee genus Stilbochlora, with a preliminary key (Hymenoptera: Halictidae), Journal of Melittology 2019 (89), pp. 1-15 : 2-5

Stilbochlora graceae Engel , new species

( Figs. 1, 2 , 9 , 12 , 16 )

ZooBank: urn:lsid:zoobank.org:act:1CA65FFD-5DA7-4D9B-A371-F39FD6E62003

DIAGNOSIS: This species, like the others described herein, differs most readily from the type species, S. eickworti , in the more densely striate propodeum. Among the remaining species it is one two in the genus with the striae extending beyond midlength and medially reaching nearly to the posterior border ( Figs. 12 , 16 ), such that the striate area is roughly triangular in form ( Figs. 12 , 16 ). Additionally, the species is noticeably green in color ( Figs. 1, 2 ) rather than the predominantly blue coloration of the other species. It can also be recognized by the testaceous clypeal apex ( Fig. 9 ), similar in this regard to S. eickworti ( Fig. 10 ), and the largely testaceous legs ( Figs. 1, 2 ).

DESCRIPTION: ♀: Total body length 6.70 mm; forewing length 5.02 mm. Head slightly wider than long (length 1.80 mm, width 1.87 mm); distal half of clypeus projecting below lower tangent of compound eyes; frontal line carinate from approximately 0.25× torular diameter below toruli to point slightly more than torular diameter above toruli; upper interorbital distance 1.03 mm; lower interorbital distance 0.77 mm; ocellocular distance approximately 1.5× ocellar diameter. Scape long, extending to level of lateral ocelli; pedicel longer than first flagellomere; first and second flagellomeres subequal in length. Gena narrower than compound eye in profile. Mesoscutum with median and parapsidal lines moderately impressed, parapsidal line approximately 0.75× length of median line; intertegular distance 1.43 mm; mesoscutellum nearly twice as long as metanotum, approximately subequal to basal area of propodeum. Forewing with basal vein distad 1cu-a by 4× vein width; 1rs-m straight, confluent with 1m-cu, roughly parallel to 2Rs; 3Rs subequal to r-rs, and subequal to 4Rs; 5Rs comparatively straight, thus marginal cell tapering uniformly to acutely rounded apex; 2M slightly longer than 3Rs; 3M approximately 2× length 2M; 2rs-m weakly curved, distad 2m-cu by 4× vein width; hind wing with distal hamuli arranged 2-1-2. Inner metatibial spur with five branches, not including apical portion of rachis.

Clypeus centrally with weak, coarse punctures separated by less than a puncture width, integument between such punctures smooth, punctures near margins slightly smaller and separated by a puncture width or less, with integument between marginal punctures weakly and finely coriarious; supraclypeal area with punctures separated by 0.75–2× a puncture width, integument between punctures weakly and finely coriarious; face below tangent of antennal toruli with minute punctures separated by a puncture width or often less, except more widely spaced near antennal torulus, integument between punctures smooth; face above tangent of antennal toruli with minute punctures nearly contiguous, integument between punctures, where evident, smooth; punctures becoming more spaced toward ocellar area and in ocellocular area, separated by 1–4× a puncture width, integument between punctures smooth; vertex with integument as described for ocellocular area; gena as on vertex, blending ventrally to coriarious integument of postgena; postgena prominently coriarious and impunctate. Pronotum smooth; mesoscutum with minute punctures separated by 2–4× a puncture width, except more closely spaced around parapsidal line, integument between punctures smooth; tegula largely smooth and impunctate except a few, sparsely scatered, minute, weak, shallow punctures; mesoscutellum with integument as on central disc of mesoscutum except punctures along posterior border larger and weaker; metanotum minutely nodulose, integument otherwise smooth; preëpisternum with coarse punctures separated by less than a puncture width, integument between punctures smooth, hypoepimeral area with sparse, small punctures, otherwise smooth; mesepisternum with small, shallow punctures separated by 1–3× a puncture width; metepisternum smooth with sparsely scatered minute punctures; basal area of propodeum smooth, glabrous, shining, with prominent striae radiating from basal margin, striae long, extending beyond midlength of basal area, medially extending nearly to posterior rounded margin, striae closely spaced (versus widely spaced and short in S. eickworti ); lateral and posterior surfaces of propodeum smooth with scatered minute punctures. Metasomal tergum I largely smooth, with scatered minute punctures, such punctures more numerous in narrow area near to apical margin, apical margin finely, weakly, transversely coriarious and impunctate; terga II–IV as on tergum I except minute punctures of disc more numerous, separated by 1–3× a puncture width, becoming weaker toward apical margin, apical margin as on tergum I; tergum V as on preceding terga except punctures more prominent and more closely spaced; sterna with basal areas smooth and impunctate, central discs finely coriarious and nodulose at setal bases.

Mandible yellow brown, with reddish brown apex and brown base; labrum yellow brown; clypeus largely brown with apex transversely yellow brown, and some metallic green highlights along lateral and basal margins; supraclypeal area brown with strong metallic green and golden highlights; remainder of face brilliant metallic green with golden highlights, with areas of weak, blue opalescence on vertex; gena and postgena as on face; antennal scape, pedicel, and first flagellomere yellowish brown to brown, remainder of flagellum brown except apex and venter of distalmost flagellomere brownish yellow. Pronotum brown with strong metallic green highlights; propleuron brown with weaker metallic green highlights; mesoscutum brilliant metallic green with some golden highlights and areas of weak blue opalescence; tegula brownish yellow, semi-translucent; mesoscutellum and metanotum as on mesoscutum; mes- and metepisternum as on mesoscutum; propodeum as on mesoscutum; legs largely light brown to brownish yellow. Wing membranes hyaline and clear; veins dark brown to brown. Metasoma largely brown; terga with strong metallic green highlights, highlights weaker to absent in marginal areas giving metasomal dorsum superficial banded appearance.

Pubescence largely white to pale yellow; face with scatered, fine, simple, suberect to erect setae, such setae intermingled with shorter, highly branched to plumose setae on lower face and along ocular borders, such setae not obscuring integument, on upper face fine erect setae short, becoming longer again on vertex and between ocelli; gena with setae as on vertex except long, erect to suberect setae with a few apical branches; postgena with sparse, elongate, erect setae, some setae with a few apical branches but largely simple. Mesoscutum with scatered, short, fine, erect, simple setae, such setae longer anteriorly, some setae, particularly along borders, with a few, short branches; mesoscutellum as on mesoscutum except intermingled with thicker, elongate, erect setae with short branches, some lateral setae almost feathery in appearance; metanotum as on mesoscutum except elongate setae more prominent; pleura with long, erect to suberect, simple setae, such setae becoming progressively slightly longer ventrally; basal area of propodeum glabrous; lateral and posterior surfaces with setae as on pleura except more numerous on lateral surface and sparser and more erect on posterior surface. Setae of legs largely pale yellow, except darker on outer surface of metatibia, and particularly dark fuscous at bases around metabasitibial plate. Metasomal tergum I with long, erect, simple setae on anterior-facing surface, such setae becoming sparse, short, and more inclined medioapically, dorsal-facing surface with sparse, short, suberect setae, narrow apical margin glabrous; terga II–IV with fine, short, suberect to subappressed, simple setae, largely directed toward obliquely outward from midline, intermingled, particularly laterally, with longer, suberect, simple setae, such longer setae progressively more numerous on succeeding terga and slightly fuscous; tergum V with setae more numerous than on preceding terga and more coppery in appearance; central discs of sterna with abundant, elongate, erect, simple setae, a few with short branches.

♂: Latet.

HOLOTYPE: ♀, Peru: Dept. Loreto, 1.5 km N Teniente Lopez , 2°35.66’S, 76°06.92’W, 20 July 1993, 210– 240 m, Richard Leschen, ex: flight intercept trap ( SEMC).

ETYMOLOGY: The specific epithet honors Ms. Grace Alexandra Laïlle (b. 2004), beloved niece.

Figures

Figures 1–2. Holotype female of Stilbochlora graceae, new species. 1. Lateral habitus. 2. Dorsal habitus.

Figures 7–10. Facial views of species of Stilbochlora Engel et al. 7. Stilbochlora wedmanorum, new species. 8. S. kateae, new species. 9. S. graceae, new species. 10. S. eickworti (Engel et al.).

Figures 11–14. Mesosomal dorsa of species of Stilbochlora Engel et al. 11. Stilbochlora eickworti (Engel et al.). 12. S. graceae, new species. 13. S. kateae, new species. 14. S. wedmanorum, new species.

Figures 15–18. Mesoscutella, metanota, and propodea of species of Stilbochlora Engel et al. 15. Stilbochlora eickworti (Engel et al.). 16. S. graceae, new species. 17. S. kateae, new species. 18. S. wedmanorum, new species.