Noteriades Cockerell, 1931.

Small to modest-sized (4.5–10.2 mm), non-metallic, hoplitiform bees lacking integumental maculation; mandible of female quadridentate, without differentiated cutting edges, mandible of male bidentate; malar space linear; clypeus slightly projecting over clypeal-labral articulation; clypeus and often supraclypeal area with mediolongitudinal carina; paraocular area with dense appressed pubescence; preoccipital carina complete. Pronotum not enlarged nor surrounding mesoscutum anteriorly; pronotal lobe and omaulus carinate, with defined omaular surface; mesoscutellum flat, carinate posteriorly, overhanging metanotum (scarcely so in N. pulchripes); propodeum wholly vertical, without basal subhorizontal zone; outer surfaces of pro- and mesotibiae apically with an acute angle and distinct notch anteriorly, therefore appearing bispinose in apical view; arolia present on all legs in both sexes (absent in Megachilina except Matangapis Baker & Engel and Heriadopsis Cockerell). Metasomal tergum I carinate dorsally at angle between anterior- and dorsal-facing surfaces; tergum VI of female nearly vertical except for apical flange-like hyaline margin, without preapical carina, tergum VI of male without preapical carina (present in Megachilina); terga V and VI of male strongly curved ventrally (only terga I–IV visible in dorsal view), covering tergum VII and sterna III–VI (no so in Megachilina); sternum I of male produced over its apical margin subapically, forming double carina (not so in Megachilina); volsella distinct, with well-developed digitus and cuspis, with heavily sclerotized denticles resembling those of short-tongued bee families and Pararhophites Friese. Refer to Gonzalez et al. (2019) for the supraspecific classification of Megachilini.

As for the subtribe (vide supra).

Holotype. Vietnam: ♀, Hoà Binh, Mai Chàu, Hang Kia, alt. 1200 m, 12.vi.2008 [12 June 2008], Liên Thị Phương Nguyễn, Phong Huy Phạm leg.” [IEBR].

Paratypes. Vietnam: 1♀, same data as holotype [SEMC]; 1♀, Tuyên Quang, Hàm Yên, Yên Thuận, Cao Đường, Cham Chu NR, 22°20'16.4"N, 103°51'09.4"E, alt. 670 m, 16.v.2019 [16 May 2019], Cường Quang Nguyễn, Liên Thị Phương Nguyễn leg.; 2♀♀, Kon Tum, Sa Thầy, Chư Mom Ray NP, 14°47'24.5"N, 107°59'46.5"E, alt. 729 m, 25.iv.2016 [25 April 2016], Liên Thị Phương Nguyễn, Đắc Đại Nguyễn, Ngát Thị Trần leg.; 6♀♀, Kon Tum, Sa Thầy, Chư Mom Ray NP, Ro Koi RS, 14°27'25"N, 107°36'22"E, alt. 267 m, 25.iv.2022 [25 April 2022], Liên Thị Phương Nguyễn, Ngát Thị Trần leg. [IEBR].

The female of this species is most similar to that of N. jenniferae as both have the apical margin of the clypeus crenulate, the mediolongitudinal carina distinctly extends onto the supraclypeal area; and the apical margin of the mesoscutellum is rounded, without apicolateral spines. The new species can be distinguished in the female from latter species by the following characters: F1 shorter than F2 (F1 about as long as F2 in N. jenniferae); the rim of the antennal torulus mesodorsally extended into a short lamellate tubercle (the rim of the antennal torulus unmodified and not mesodorsally extended in N. jenniferae); mesosoma approximately as long as broad (mesosoma longer than broad in N. jenniferae). In addition, the new species differs from both N. jenniferae and N. spinosus by the generally shiny face and mesoscutum, which is matte in the latter two species.

♀: Body length 8.0–8.5 mm (holotype = 8.5 mm), forewing length 5.5–6.0 mm (holotype = 6.0 mm).

Structure. Head slightly broader than long, approximately 1.1× as broad as long (Fig. 3). Compound eyes subparallel, 2.5× as long as broad, about 1.3× genal width. Mandible quadridentate, without differentiated cutting edges. Clypeus slightly convex on basal half, 1.8× as broad as long, apical margin crenulate, mediolongitudinal carina distinct, extending onto supraclypeal area (Fig. 3). Supraclypeal area slightly convex. Juxtantennal carina absent. Interantennal distance about 1.6× median ocellar diameter; antennal torulus with rim mesodorsally extended into short lamellate tubercle (Fig. 4), scape about 2.6× as long as broad, pedicel approximately 1.5× as long as broad and about 2× F1 in length, F1 broader than long and about 0.75× F2 in length, F3–F9 subequal in length, F10 longest flagellomere, longer than broad. Mesosoma approximately as long as broad (Fig. 5); mesoscutum without spine or sharp angle apicolaterally; mesoscutellum apical margin rounded, without apicolateral spines (Fig. 5). Forewing prestigma about as long as 1Rs; pterostigma longer than broad (Fig. 6), margin inside marginal cell convex; marginal cell apex broadly rounded and minutely appendiculate, offset from anterior wing margin; 1Rs not perfectly aligned with 1M, 1M weakly arched anteriorly, distad 1cu-a by about 2–2.5× vein width, thus forming exceedingly short 2M+Cu; Rs+M faintly sinuate; two submarginal cells (i.e., 1rs-m absent), first submarginal cell broader than second submarginal cell; 1Rs straight, about as long as r-rs; r-rs arising at pterostigmal midlength; 1m-cu strongly distad 1Rs; 2m-cu basad 2rs-m (in some paratypes, 2m-cu confluent with 2rs-m), 2rs-m strongly arched. Pretarsal claws with arolia on all legs. Anterior-facing surface of T1 strongly concave (Fig. 2) and dorsally rimmed by strong carina. Pygidial plate absent.

Sculpturing and texture. Integument of head and mesosoma generally shiny. Mandible and labrum irregularly punctate, punctures slightly coarser on mandible basally, outer ridges smooth and shiny. Clypeus with contiguous punctures of unequal sizes, puncture sizes laterally and along base larger than on remainder of surface (Fig. 3). Supraclypeal area with contiguous punctures, puncture sizes as on base and sides of clypeus. Frons with contiguous, large, coarse punctures (Fig. 4). Punctures on vertex and gena larger and coarser than on frons, punctures largest on gena. Pronotum with dense coarse punctures, punctures smaller than those on mesoscutum. Mesoscutum with largely contiguous, coarse punctures of subequal sizes, punctures of disc more separated, separated by 0.2–0.5× a puncture width, integument between faintly imbricate; tegula imbricate and impunctate; axilla with contiguous coarse punctures, punctures about 0.5× size of those on remainder of mesoscutellum; mesoscutellum with contiguous, large, coarse punctures, punctures much coarser than those on gena, almost appearing areolate (Fig. 5). Mesepisternum with large, coarse punctures on upper half, separated by about 0.3–0.5× a puncture width, lower half with smaller, denser punctures, such punctures nearly contiguous (Fig. 1). Anterior-facing surface of T1 smooth, shining, impunctate; dorsal-facing surface of T1 and remaining metasomal terga with nearly contiguous, smaller punctures resembling those of frons, except laterally punctures noticeably larger, coarser, and contiguous; S1 with small, sparse punctures; S2–S6 with small, dense punctures, except marginal zones impunctate.

Figures 1, 2. 

Noteriades hangkia Tran, Engel & Nguyen, sp. nov., holotype, female 1 habitus in lateral view 2 habitus in dorsal view. Scale bars: 1 mm.

Figures 3–6. 

Noteriades hangkia Tran, Engel & Nguyen, sp. nov., holotype, female 3 head in facial view 4 head in anterolateral oblique view showing lamellate extensions from antennal torular rims (red arrows) 5 mesosoma in dorsal view 6 forewing, dorsal view. Scale bars: 1 mm (3, 5–6); 0.5 mm (4).

Color. Body black except antenna beneath, tegula, tarsi, and metasomal sterna apical margins dark reddish brown. Wings light brown with faint green mixed coppery highlights in ventral view, membrane of marginal cell and apex darker brown than remainder of remigium and lighter in radial and first cubital cells; veins brown to dark brown, prestigma and pterostigma dark brown.

Pubescence. Paraocular area from epistomal sulcus to slightly above antennal toruli with long, dense, plumose, appressed, white setae, some setae tinged yellowish (Fig. 1). Apical margin of clypeus with sparse, erect, yellow to tawny yellow setae. Outer surfaces of mandible and labrum with minute, erect, yellow to tawny yellow setae, particularly numerous in grooves of mandible. Dorsal surface of pronotal collar, pronotal lobe, lateral surfaces of coxae with short, minutely branched, yellow to yellow tawny setae, those more dorsally on pronotal lobe off white; metanotum and propodeum with longer, erect, minutely branched, yellow setae. Retrolateral surfaces of tarsi with dense, erect, yellowish setae. Metasomal T1–T4 with apical fasciae composed of yellowish plumose setae, medially interrupted on T1–T2, interruption with weak vibrissae composed of scattered, minute, simple setae on T1 (Fig. 2), otherwise discs with scattered short, suberect, yellowish, simple setae, such setae more prominent laterally and progressively longer on T4–T5; S2–S6 with yellowish scopal setae (Fig. 1).

♂: Latet.

The specific epithet is a toponym for the locality at which the holotype was collected, the Hang Kia commune in Hoa Binh Province. The name is treated as a noun in apposition.

The discovery of N. hangkia in the northern and central highlands of Vietnam extends the distribution of the genus Noteriades in Southeast Asia (Fig. 7). In fact, it is likely that the genus shall be found eventually in Laos, Cambodia, and southernmost China.

Figure 7. 

Distribution map of Southeast Asian species of Noteriades Cockerell (Megachilinae: Megachilini: Noteriadina).