Lasioglossum Curtis 1833
Creators: name: Hettiarachchi, Thilina
name: Gibbs, Jason
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Halictidae
Lasioglossum

description: Key to Lasioglossum subgenera in North America
Modified from McGinley (1986), Michener (2007), and Gibbs et al. (2013).
1. Second submarginal crossvein (1rs-m) as strong as first (second abscissa of Rs) (Fig. 16A), difficult to see in male; head and mesosoma black, except L. pavonotus (Cockerell); male clypeus often flat or depressed ventrally; flagellomere 2 subequal to pedicel and flagellomere 1 combined (Fig. 17A); body length usually greater (approx. 7–12 mm)..................... 2
- Second submarginal crossvein (1rs-m) weaker than first (second abscissa of Rs) (Fig. 16B), at least in female; head and mesosoma variable in colour; male clypeus often rounded; flagellomere variable, if black and moderately large (> 6 mm), then flagellomere 2 longer than pedicel and flagellomere 1 combined (Fig. 17B)....................................... 3
2. Propodeum with lateral carina well developed, reaching dorsal surface (Fig. 18A); dorsal surface coarsely sculptured, shorter than scutellum (Fig. 18A); T1 without basal hair band (Fig. 18A); head long (length/width ratio = 0.88–1.0) (Fig. 19A); male gonostylus without retrorse lobe (Fig. 20A)................................................... L. (Leuchalictus)
- Propodeum with lateral carina usually poorly developed, not reaching dorsal surface (Fig. 18B), but if strong (Figs. 18C, 18D) then dorsal surface longer than scutellum (Fig. 18C) or weakly sculptured (Fig. 18C) or T1 with basal hair band or head short (Fig. 18D) (length/width ratio = 0.77–0.89) (Fig. 19B); male gonostylus with retrorse lobe (Fig. 20B).... L. (Lasioglossum)
3(1). Head and mesosoma distinctly metallic (green, blue, or golden)................................................ 4
- Head and mesosoma black-brown, at most with weak reflections............................................... 6
4. Head and mesosoma brilliant metallic (Antillean, southern Florida); male inner metatibial spur typically pectinate; male gonostylus without retrorse lobe........................................................... L. (Habralictellus)
- Head and mesosoma dull metallic; male inner metatibial spur ciliate; male gonostylus with retrorse lobe................ 5
5. Body size usually small (3.5–6 mm); female T1 usually with appressed hairs at least laterally (Fig. 21A) in North American species (except L. ruidosense and L. petrellum (Cockerell) species complexes, L. microlepoides (Ellis), L. pavoninum (Ellis)), typically lacking erect hairs medially; female mandible almost always with small preapical tooth (Fig. 21B), except in the wood-nesting L. coeruleum (Robertson)) (cosmopolitan)............................................ L. (Dialictus)
- Body size usually larger (6–8 mm); female T1 without appressed hairs, medially with distinct erect hairs (Fig. 22A); female mandible often strongly bidentate (Fig. 22B), if preapical tooth small, then propodeum with distinct lateral carina reaching dorsal margin (primarily from Panama to Mexico, except L. aquilae, which reaches to high elevation areas in the southwestern USA)................................................................................ L. (Eickwortia s.l.)
6 (3). Head wide (Fig. 23A); female inner metatibial spur with fine oblique teeth, not as tall as width of main rachis (Fig. 23A); male gonostylus without retrorse lobe; metasomal sterna with erect pubescence.............................. L. (Evylaeus)
- Head usually longer (Fig. 23B); female inner metatibial spur usually with longer, narrow or fat teeth, often taller than width of main rachis basally (Fig. 24B); male gonostylus with retrorse lobe; metasomal sterna with variable pubescence.......... 7
7. Foretibia of female with long projection (Fig. 25A); metapostnotum enclosed by carina, with distinct parallel carinulae (Fig. 26A); frons with two bulbous protuberances (Fig. 26B); retrorse lobe absent (Neotropical)....................................................................... L. gattaca complex (L. gattaca and L. hartmanni Danforth and Wcislo)
- Foretibia of female without long projection (Fig. 25B); metapostnotum not as above; retrorse lobe present (widespread)... 8
8. Female mandible strongly bidentate (Fig. 27), subapical tooth nearly equal to apical one; male metasoma with entirely paleorange sterna; gonobase at middorsum less than one-fourth length of gonocoxite; T1 narrow or apex of clypeus distinctly thick (Mexico and Central America)........................................................... L. (Eickwortia s.s.)
- Female mandible with small preapical tooth dorsally; male gonobase at middorsum usually more than one-third length of gonocoxite.......................................................................................... 9
9. Either propodeum with weak lateral carina and fully developed scopa (Figs. 28A, 28B) or mesosoma coarsely sculptured on pleuron and carina appearing to reach dorsal surface (Figs. 28C, 28D); male metasomal sterna with erect pubescence; male antennae usually relatively short; male heads sometimes enlarged with long mandibles (Fig. 28E)....... L. (Hemihalictus)
- Either propodeum with weak lateral carina and highly modified reduced scopa (Figs. 29A, 29B) or mesosoma weakly rugose at most and propodeum with complete carina (Figs. 29C, 29D); male metasomal sterna nearly bare, except in Onagraceae specialists; male antennae relatively long (Fig. 4C); male heads not enlarged (Fig. 4B).............. L. (Sphecodogastra)
description: Published as part of Hettiarachchi, Thilina & Gibbs, Jason, 2024, A problematic species complex for Lasioglossum subgeneric diagnostics in North America (Hymenoptera: Halictidae), pp. 206-235 in Zootaxa 5404 (1) on page 226, DOI: 10.11646/zootaxa.5404.1.13, http://zenodo.org/record/10566480