Trichommation osculans Engel, 2019

Engel, Michael S., 2019, A new genus of augochlorine bees from northern Venezuela (Hymenoptera: Halictidae), Journal of Melittology 2019 (87), pp. 1-15 : 9-12

Trichommation osculans Engel , new species

ZooBank: urn:lsid:zoobank.org:act:1CEA7AB0-6226-4F26-8DB6-3F40A0795241

( Figs. 1–16 )

DIAGNOSIS: As for the genus (vide supra).

DESCRIPTION: ♀: Total body length 9.5 mm; forewing length 7.9 mm. Head slightly wider than long, length 2.07 mm, width 2.33 mm. Upper interorbital distance 1.07 mm; lower interorbital distance 0.93 mm. Compound eyes with fine, white ocular setae, individual setae much longer than an individual ommatidial diameter ( Fig. 9 ). Intertegular distance 1.83 mm; mesoscutellum weakly bigibbous. Protibial calcar of strigilis with primary velum somewhat rectangular, with inner margin (long border) straight except rounded proximally and apically, apical margin largely bordered by sclerotized thickening from rachis; malus elongate, straight, longer than velum, inner margin minutely ciliate ( Fig. 13 ); inner metatibial spur pectinate, with five branches ( Fig. 16 ), not including apical portion of rachis. Forewing ( Fig. 10 ) with basal vein distad 1cu-a by two times vein width; first submarginal cell slightly longer than combined lengths of second and third submarginal cells; second submarginal nearly quadrate, anterior border along Rs only slightly shorter than posterior border, anterior border about as long as anterior border of third submarginal cell along same vein (i.e., 3Rs and 4Rs nearly equal); posterior border of third submarginal cell slightly less than twice length of anterior border; 1rs-m confluent with 1m-cu; 2rs-m faintly arched, distad 2m-cu by six times vein width; hind wing with distal hamuli arranged 2-1-2.

Clypeus and supraclypeal area with coarse, shallow punctures separated by less than a puncture width or more, integument between punctures coriarious; face with small, contiguous, irregular punctures giving integument a roughened appearance, such punctures becoming weaker on lower face and blending to coriarious integument, similarly blending to imbricate-coriarious integument in ocellocular area and on vertex; gena and postgena coriarious. Pronotum finely coriarious to imbricate. Mesoscutum with small contiguous punctures, punctures slightly more spaced outside parapsidal lines, punctures weaker and more separated posteriorly; tegula faintly coriarious anteriorly with scatered minute punctures, posteriorly smooth and impunctate; mesoscutellum with faint small punctures in anterior third, punctures contiguous medially, elsewhere separated by a puncture width or more, blending to imbricate and coriarious integument posteriorly; metanotum minutely nodulose; pleura with coarse, small, weak punctures separated by less than a puncture width, such punctures becoming weaker and more drawn out ventrally, integument between finely and weakly coriarious; lateral and posterior surfaces of propodeum imbricate to coriarious, basal area of propodeum coriarious, with short basal rugae. Metasomal terga and sterna imbricate.

Mandible dark brown near base, otherwise largely reddish brown; labiomaxillary complex amber brown, with yellow palpi; labrum reddish brown; clypeal apex light reddish brown (almost fulvous), remainder of clypeus, supraclypeal area, face, and vertex reddish brown, with metallic green and blue reflections on lower face, margins of supraclypeal area and clypeus around subantennal sulci and lateral borders of epistomal sulcus; scape largely reddish brown except lighter on ventral surface; pedicel and flagellum reddish brown to brown except somewhat lighter ventrally and apically on flagellum, particularly so by apical flagellomere; gena and postgena reddish brown with strong metallic green to green-blue highlights, particularly on gena. Pronotum as described for gena; propleuron light reddish brown; mesoscutum largely reddish brown with scatered metallic highlights along borders ( Fig. 11 ); tegula as on mesoscutum without highlights; mesoscutellum and metanotum metallic green, with golden to brassy highlights, particularly on metanotum ( Figs. 10, 11 ); pleura metallic green with golden to brassy highlights ( Fig. 2 ); propodeum metallic green with golden and brassy highlights ( Fig. 12 ). Wing membranes like light parchment ( Figs. 1 , 5 ); veins largely amber colored except darker on C and Sc+R and lighter on R and Rs beyond tangent with submarginal cells ( Fig. 10 ). Legs largely light reddish-orange brown to light amber brown ( Figs. 1 , 14 ); pro- and mesotibial spurs yellow, outer metatibial spur yellow, inner metatibial spur amber. Metasoma dark reddish brown to dark brown on apical terga and sterna ( Fig. 1 ).

Pubescence generally amber to golden yellow ( Figs. 1, 2 ) except largely fuscous on terga II–VI and sterna V–VI; scopal setae distinctly golden yellow ( Figs. 1 , 14 ).

♂: Latet.

HOLOTYPE: ♀ ( Figs. 1 , 5 ), Venezuela, [Aragua: Parque Nacional Henri Pitier, Rancho Grande Biological Station], Pico Periquito [approximately 10°20’26’’N, 67°42’03’’W], 16 Aug 1967, R. W. Poole; deposited in the Division of Entomology, University of Kansas Natural History Museum , Lawrence, Kansas.

ETYMOLOGY: The specific epithet refers to the word osculant, meaning “interme- diate between two taxa”, and derived from the Latin word ōsculāns , itself meaning, “kissing”. The name refers to the intermingling of features of Megommation and Megaloptidia in this taxon.

COMMENT: Pico Periquito is situated inside Aragua along the border with Carabobo, and due north of Mariara, and is a well-known locality for bird watching. Further exploration for crepuscular and matinal bees in the area would be fruitful, ideally leading to the discovery of the yet-unknown male for this species.

Figures

Figures 1–2. Holotype female of Trichommation osculans, new genus and species. 1. Lateral habitus. 2. Lateral detail of head and mesosoma.

Figures 3–5. Holotype female of Trichommation osculans, new genus and species. 3. Facial view. 4. Ventral view of head. 5. Dorsal habitus.

Figures 6–7. Labral and clypeal details from holotype female of Trichommation osculans, new ge- nus and species (clypeal angles of marginal area highlighted in green). 6. Direct view of clypeal apex and labral basal area. 7. Oblique view of clypeal apex and narrow labral distal process.

Figures 8–9. Head details of Trichommation osculans, new genus and species. 8. Lateral oblique view of labiomaxillary complex and hypostomal lamella (arrow points to posterior enlargement of lamella). 9. Detail of compound eye showing fine ocular setae.

Figures 10–13. Details of holotype female of Trichommation osculans, new genus and species. 10. Forewing. 11. Detail of mesoscutum, mesoscutellum, and metanotum. 12. Detail of mesoscutellum, metanotum, and basal area of propodeum. 13. Detail of protibial calcar.

Figures 14–17. Details of holotype female of Trichommation osculans, new genus and species, and Megommation insigne (Smith). 14. Hind leg of T. osculans. 15. Metabasitibial plate of T. osculans. 16. Inner and outer metatibial spurs of T. osculans. 17. Hind leg of M. insigne.