Lasioglossum (Eickwortia) hienae Gibbs & Dumesh, 2013

Gibbs, Jason & Dumesh, Sheila, 2013, A new species, Lasioglossum (Eickwortia) hienae, from Mexico (Apoidea: Halictidae), Journal of Melittology 2013 (13), pp. 1-11 : 3-6

Lasioglossum (Eickwortia) hienae Gibbs & Dumesh , new species

ZooBank: urn:lsid:zoobank.org:act:D336B46B-D9D7-472C-BA58-7A4D2FDAB589

( Figs. 1–4, 6, 7 )

DIAGNOSIS: Females of L. hienae can be distinguished from other Halictidae by the following combination of characters: forewing with vein 1rs-m, and 2rs-m weak [as in L. (Dialictus) Robertson, L. (Evylaeus), and L. ( Sphecodogastra ) Ashmead]; anterior third of forewing infuscate ( Fig. 1 ); mandible strongly bidentate ( Fig. 3 ); mesoscutum granulate, obscurely doubly punctate ( Fig. 4 ).

Lasioglossum hienae is most similar to L. nyctere , but the latter has the mesoscutum tessellate with distinct double punctures (fine punctures separated by 1–2 diameters, coarse punctures separated by 5–10 diameters) ( Fig. 5 ). Lasioglossum alexanderi has completely infuscate forewings, mesoscutum distinctly singly punctate, and metapostnotum regularly carinulate to posterior rim (vide McGinley, 1999).

Additional useful characters for recognizing L. hienae include the following: Integument blackish brown ( Fig. 1 ). Off-white, appressed tomentose setae on the pronotal lobe, dorsolateral angle of pronotum, posterior margin of mesoscutum, metanotum, posterior surface of the propodeum and basal portions of T2–T3 ( Figs. 4, 6, 7 ), which sharply contrast with the black integument. Head wider than mesosoma ( Fig. 2 ); compound eyes weakly divergent below ( Fig. 2 ). Pronotal lateral ridge complete; pronotal lobe acutely projected laterally ( Fig. 2 ). Hind wing with distal hamuli organised 3-1- 1-1-2 [typically 2- 1-2 in L. (Dialictus), L. (Evylaeus), and L. ( Sphecodogastra )]. Femora slender; inner metatibial spur pectinate, with four long branches (not including apex of rachis). Metapostnotum smooth with virtually no microsculpture ( Figs. 4, 6 ).

The male of L. hienae is unknown. Males of L. nyctere are similar to females, except they have smaller heads, normal mandibles, and a remarkably slender metasoma. They bear a close resemblance to males of the augochlorine genus Neocorynura Schrottky. It is expected that males of L. hienae may have similar traits.

DESCRIPTION: ♀, Length 6.5 mm. Head length 1.95 mm. Head width 2.31 mm. Intertegular distance 1.43 mm.

Color. Entire body blackish brown ( Fig. 1 ), except: Antennal flagellomere 10 reddish brown apically. Tegula dark reddish brown ( Fig. 4 ). Legs dark brown, except medio- and distitarsi reddish brown ( Fig. 1 ). Forewing membrane dusky, anterior margin deeply infuscate ( Fig. 1 ). Pterostigma and venation reddish brown. T2 with margin translucent reddish brown ( Fig. 7 ).

Structure. Head wide (length/width ratio = 0.84) ( Fig. 2 ). Labrum with basal tubercle; apical process broadly triangular. Mandible bidentate, preapical tooth nearly as long as apical tooth ( Fig. 3 ). Clypeus 3x wider than long, extending 2/3 below suborbital line ( Fig. 2 ). Compound eyes weakly divergent below, upper ocular distance 0.93x lower ocular distance ( Fig. 2 ). Gena 1.4x wider than compound eye in lateral view, widest at midlength. Hypostomal carinae subparallel. Ocelli unmodified. Vertex broad, extending 1.5 OD above lateral ocellus in frontal view ( Fig. 2 ). Pronotum maximum width 2.13 mm; dorsolateral angle obtuse; pronotal ridge carinate, not interrupted by sulcus; pronotal lobe acutely projecting laterally ( Fig. 2 ). Femora and metatibia slender. Inner metatibial spur pectinate, four-toothed, basal tooth longer than width of rachis. Tegula ovoid ( Fig. 4 ). Forewing with marginal cell very narrowly truncate; submarginal cells three; veins 1rs-m and 2rs-m weak. Propodeal lateral carina not reaching dorsal margin, oblique carina absent ( Figs. 6, 7 ). T1 narrow, 0.7x width of T2; T5 with distinct pseudopygidial area ( Fig. 7 ).

Surface sculpture. Face imbricate except as follows ( Fig. 2 ): Clypeus polished distally. Clypeus, supraclypeal area, and lower paraocular area sparsely punctate (i = 1–3 d). Upper paraocular area and frons reticulate. Gena weakly imbricate, punctures sparse (i = 1–2 d), postgena imbricate. Mesoscutum coarsely imbricate, granular; punctures very fine, mostly dense (i ≤ 1 d), difficult to distinguish from background microsculpture, except coarser and sparser on anterior portion (i = 2–4 d) ( Fig. 4 ). Mesoscutellum similar to mesoscutum. Mesepisternum with vertical carinulae converging on subpleural signum, coarser ventrally; hypoepimeral area imbricate. Metepisternum transversely carinulate on dorsal third, remainder imbricate. Metapostnotum smooth, weakly imbricate, not shiny ( Fig. 4 ). Propodeum imbricate, lower lateral surface with weak transverse carinulae. Metasomal terga mostly imbricate, apical impressed area coriarious, T1 smoother ( Fig. 7 ); punctures fine, dense (i = 1–1.5 d), nearly reaching posterior margin ( Fig. 7 ); T5 pseudopygidial area coarsely punctate (i = 1–1.5 d).

Pubescence. Dull white, except tomentum faintly yellowish, largely dark brown on tibiae and tarsi ( Fig. 7 ). Entire body with sparse woolly setae (1–1.5 OD), longer on metanotum, mesopleuron and lateral portions of metasomal terga (1.5–2.5 OD). Paraocular area with short, subappressed tomentose setae ( Fig. 2 ). Gena with tomentum adjacent to compound eye ( Fig. 1 ). Pronotal lobe and posterior margin with dense tomentum ( Figs. 1 , 4 ). Mesoscutum with posterior margin tomentose ( Fig. 4 ). Metanotum almost entirely obscured by tomentum ( Fig. 4 ). Metafemur with well developed scopa ( Fig. 7 ). Propodeal posterior surface obscured by tomentum ( Fig. 7 ), dorsal portion of lateral surface with sparse tomentum. T1 with sparse, erect plumose setae; T2 –T4 with dense basal tomentose bands, thickest and most evident on T2 ( Fig. 7 ). Metasomal sterna with plumose scopa (3–4.5 OD).

♂: Unknown.

HOLOTYPE: ♀, Mexico: Colima, Volcán Colima, South Road , W side of river, N19.45166 W103.71814, 1163m, 0.5.x.10, S. Dumesh, PCYU-MEX10-0175 [on white label] / BeeBOL, CCDB-09841 E07, BOWMT150-10 [on green label] / HOLOTYPE Lasioglossum (Eickwortia) hienae [on red label]. Deposited in Packer Collection , York University. Specimen in good condition except midleg on right side removed for molecular study .

DISTRIBUTION: Only a single female specimen is known, collected from the southern slope of the Colima volcano on the border of Colima and Jalisco Provinces, Mexico ( Figs. 8, 9 ). The specimen was collected at a relatively high elevation (1163 m), as were other specimens in the subgenus ( McGinley, 1999) ( Figs. 8, 9 ). The nearest recorded location of L. nyctere is nearly 200 km distant. The type locality of L. hienae is at the edge of the predicted area of suitable habitat for L. nyctere ( Fig. 8 ).

DNA BARCODES: A single partial DNA barcode sequence (407 bp) is available from the holotype specimen of L. hienae (GenBank accession: KF199918). A single partial DNA barcode sequence (382 bp) is also available from a specimen of L. nyctere from Veracruz Province (near the type locality) (GenBank accession: KF199919). Thirteen nucleotide differences occur over the overlapping 382 bp (= 3.6% genetic divergence). Lasioglossum hienae differs from L. nyctere in the following sites (relative to standard bee barcodes, vide Gibbs et al., 2013): 273(C/T), 363(C/T), 435(C/A), 495(T/C), 543(A/C), 549(C/A), 564(A/G), 570(C/T), 577(C/T), 600(C/T), 603(T/C), 612(C/T), and 621(C/A). Additional sampling is needed to determine what fraction of these 13 differences is fixed between the two species, but this is consistent with species-level differences among closely related bees ( Gibbs, 2009).

ETYMOLOGY: We are pleased to name this bee for our friend and colleague Hien T. Ngo in recognition of her studies of tropical native bees and a memorable fieldwork experience in Mexico with the senior author.

Figures

Figures 1–2. Holotype female of Lasioglossum (Eickwortia) hienae, new species. 1. Lateral habitus. 2. Face. Scale bars = 1 mm.

Figures 3–7. Females of Lasioglossum (Eickwortia) hienae, new species (3, 4, 6, 7) and L. (E.) nyctere (Vachal) from Veracruz Prov., Mexico (5). 3. Mandibles. 4, 5. Dorsolateral views of mesosoma. 6. Dorsal habitus. 7. Dorsal view of metasoma and posterior view of propodeum. Scale bars = 1 mm.

Figures 8–9. Distribution of species of Lasioglossum (Eickwortia). 8. Heat map showing predicted suitable range for L. nyctere based on maximum entropy analysis. 9. Heat map indicating elevation gradients.