Lasioglossum (Dialictus), 1902

Landaverde-González, Patricia, Gardner, Joel, Moo-Valle, Humberto, Quezada-Euán, José Javier G., Ayala, Ricardo & Husemann, Martin, 2023, Seven new species of Lasioglossum (Dialictus) Robertson, 1902 (Hymenoptera: Halictidae: Halictini) from the Yucatán Peninsula, Mexico, European Journal of Taxonomy 862 (1), pp. 1-65 : 52-60

publication ID	https://doi.org/ 10.5852/ejt.2023.862.2079
publication LSID	lsid:zoobank.org:pub:5D38246E-B144-434C-A2FE-C303381B0CD7
DOI	https://doi.org/10.5281/zenodo.8290042
persistent identifier	https://treatment.plazi.org/id/03A287B8-FFD8-FF98-FF2B-DA39FAFE02CE
treatment provided by	Felipe
scientific name	Lasioglossum (Dialictus)
status

Treatment

Key to known females of Lasioglossum (Dialictus) from the Yucatán Peninsula

1. Propodeum dorsolateral slope smooth, with no oblique carina ( Fig. 22A–B View Fig ) ................................. 2

– Propodeum dorsolateral slope with an oblique carina ( Fig. 22C View Fig ) .................................................... 5

2. Metapostnotum smooth with weak rugae covering less than half its length ( Fig. 22A View Fig ); mesonotum and mesepisternum shiny due to weak or absent microsculpture ( Fig. 23A View Fig ); metasoma black to brown and without appressed tomentum .......................................................................................... 3

– Metapostnotum with strong rugae covering half or more its length ( Fig. 22B View Fig ); mesonotum and mesepisternum dull due to very strong microsculpture ( Fig. 23B View Fig ); metasoma orange to reddish brown and with some sparse appressed tomentum on T2–T4 ............................................................ .................................................................................................. L. meteorum Gardner & Gibbs, 2020

3. Clypeus apicolateral margins parallel with distinct, acute teeth ( Fig. 24A View Fig ); hind legs and tarsi of other legs light brown; abdomen dark brown, margin of segment testaceos; metanotum with abundant short plumose setae ( Fig. 23A View Fig ) ................................................................. L. exiguum ( Smith, 1879) View in CoL

– Clypeus apicolateral margins strongly convergent with indistinct, rounded knobs ( Fig. 24B View Fig ); hind legs dark brown or black, tarsi sometimes lighter; abdomen piceous, margin of segment not testaceous; metanotum with short plumose setae very sparse or absent (as in Fig. 23B View Fig ) ................ 4

4. Mesoscutum between parapsidal lines and mesoscutellum sparsely punctate (i = 2–4 pd); face broader than long ......................................................................................... L. tropicior ( Ellis, 1914)

– Mesoscutum between parapsidal lines and mesoscutellum moderately densely punctate (i = 1–2 pd); face about as long as broad or slightly longer ............................................. L. deceptor ( Ellis, 1914)

5. Tegula ovoid and relatively small, clearly not reaching posterior margin of mesoscutum in dorsal view ( Fig. 6D, G–H View Fig ) ......................................................................................................................... 6

– Tegula with inner posterior margin straight or concave, more bean-shaped, and relatively large, reaching posterior margin of mesoscutum in dorsal view or nearly so ( Fig. 6A–C, E–F View Fig ) ............... 8

6. Punctures of face uniformly large and dense ( Fig. 25A View Fig ); mesoscutum punctures large, coarse and dense (i <1 pd) and very coarse, with many punctures touching laterad of parapsidal lines (i = 0 pd) except on anteromedian margin (i> 1.5 pd) ( Fig. 26A View Fig ); propodeum with oblique carina U-shaped and extending onto dorsolateral slope ........................ L. ameshoferi Landaverde-González sp. nov. – Punctures of upper half of face distinctly smaller and denser than punctures of lower half ( Fig. 25B– C View Fig ); mesoscutum punctures between parapsidal lines sparser (i = 1–3 pd) ( Fig. 26B View Fig ); propodeum with oblique carina straight, not extending onto dorsolateral slope ......................................................... 7

7. Mesepisternum slightly sparsely punctate (i ≤ 1–1.5 d) with dense plumose setae (1–1.5 OD); metapostnotum dull, imbricate, with shallow anastomosing rugae reaching posterior margin or nearly so; mesoscutal punctation between parapsidal lines sparse (i = 1.5–3 pd), becoming moderately dense but not crowded laterad of parapsidal lines (i = 1 pd; Fig. 27A View Fig ); head about as long as broad (length/width 0.94–0.99) ( Fig. 25B View Fig ) .................................... L. milpa Landaverde-González sp. nov.

– Mesepisternum imbricate and densely punctate (i ≤ 1 pd); metapostnotum shiny to weakly tessellate, with strong, coarse rugae reaching posterior margin; mesoscutal punctation moderately sparsely punctate between parapsidal lines (i = 1–3 pd), becoming dense and crowded laterad of parapsidal lines (i ≤ 1 pd; Fig. 27B View Fig ); head broader than long (length/width 0.91–0.95) ( Fig. 25C View Fig ) ................... ............................................................... L. nanotegula Landaverde-González & Husemann sp. nov.

8. T2 and usually T3 apical rims glabrous and impunctate ( Fig. 28A View Fig ); mesoscutum with sparse erect setae ~1 OD long (most setae separated by half their length or more in lateral view) and subappressed setae little more than stubble, appearing shaved ( Fig. 29A View Fig ); mesoscutum often with copper-red reflections medially ........................................................................................................................... 9

– T2–T3 apical rims evenly covered with fine setae and/or punctures ( Fig. 28B View Fig ); mesoscutum with dense erect setae ~1 OD long (all setae separated by less than half their length in lateral view) and subappressed setae 0.25–0.5 OD long ( Fig. 29B View Fig ); mesoscutum dark turquoise-green with golden reflections ........................................................................................................................................ 10

9. Tegula lateral margin with shallow, minute, and sparse punctures (i = 1–2 d) no larger than mesoscutum punctures (sometimes inconspicuous and tegula nearly impunctate) ( Fig. 6B View Fig ); mesonotum and mesepisternum shiny; mesepisternum granular with distinct fine and dense punctures (i = 1–1.5 pd) ( Fig. 30A View Fig ) .......................................................................... L. paxtoni Landaverde-González sp. nov.

– Tegula lateral margin with deep, distinct, and dense punctures (i <1 d) slightly larger than mesoscutum punctures ( Fig. 6A View Fig ); mesonotum and mesepisternum dull with strong microsculpture; mesepisternum strongly imbricate to finely rugulose and indistinctly punctate at least dorsal half ( Fig. 30B View Fig ) .................................................................. L. yucatanense Landaverde-González sp. nov.

10. Tegula deeply and distinctly punctate (similar to mesoscutum), usually densely (i <1 pd) ( Fig. 6C View Fig ); mesepisternum usually imbricate and moderately sparsely punctate (i = 1–2 pd) ( Fig. 31A View Fig ) ........... ............................................................................................................... L. stictaspis View in CoL species complex

– Tegula finely punctate (punctures smaller than those of mesoscutum), usually sparsely (i ≥ 1.5 pd) ( Fig. 6E–F View Fig ); mesepisternum very densely punctate (i <0.5 pd) ( Fig. 31B View Fig ) ....................................11

11. Mesoscutum and supraclypeal area sparsely punctate (i = 1–3 pd); tegula with a few scattered minute punctures hardly visible at 40 × magnification ( Fig. 6E View Fig ); metapostnotum dull with shallow rugae blending into finely reticulate background microsculpture ( Fig. 32A View Fig ) .............................................. .............................................................. L. aureoviride Landaverde-González & Husemann sp. nov.

– Mesoscutum and supraclypeal area densely punctate (i = 0.5–1 pd); tegula distinctly punctate at 40 × magnification at least on lateral margins, where it is dense (i ≤ 1 pd; Fig. 6F View Fig ); metapostnotum shiny with strong anastomosing rugae ( Fig. 32B View Fig ) ....................................... L. paralepidii Gardner sp. nov.

Key to known males of Lasioglossum (Dialictus) from the Yucatán Peninsula

1. Tegula ovoid and relatively small, clearly not reaching posterior margin of mesoscutum in dorsal view (as in Fig. 6D, G–H View Fig ) ................................................................................................................ 2

– Tegula with inner posterior margin straight or concave, more bean-shaped, and relatively large, reaching posterior margin of scutum in dorsal view or nearly so (as in Fig. 6A–C, E–F View Fig ) ............... 6

2. S3–S5 pubescence long (2–4 OD), erect, and densely plumose ( Fig. 33A View Fig ); propodeum dorsolateral slope smooth, with rugae not reaching posterior margin ( Fig. 34A View Fig ) ................................................ 3

– S3–S5 pubescence short (1–2 OD), suberect, and weakly plumose, appearing simple at <40 × magnification ( Fig. 33B View Fig ); propodeum dorsolateral slope sometimes roughened by rugae reaching posterior margin ( Fig. 34B–C View Fig ) .......................................................................................................... 4

3. S4–S5 with long setae limited to median portion, hidden in dorsal view; face broader than long .... ................................................................................................................... L. exiguum ( Smith, 1879) View in CoL

– S4–S5 with long setae on extreme lateral margins visible in dorsal view; face about as long as broad ............................................................................................................ L. deceptor ( Ellis, 1914)

4. Metapostnotum with strong and coarse subparallel rugae extending onto and fully covering propodeum dorsolateral slope ( Fig. 34C View Fig ), usually with trace oblique carina present; retrorse lobe small; penis valve small and delicate .......................... L. ameshoferi Landaverde-González sp. nov.

– Metapostnotum with strong or somewhat finer rugae not extending onto propodeum dorsolateral slope except at base ( Fig. 34B View Fig ) and oblique carina absent ............................................................... 5

5. Mesepisternum densely punctate (i <1 pd) ........................................................................................ ............................................................... L. nanotegula Landaverde-González & Husemann sp. nov.

– Mesepisternum sparsely punctate (i = 1–3 pd) ........................ L. meteorum Gardner & Gibbs, 2020

6. Tegula with sparse punctures medially (i> 1.5 dp) (sometimes inconspicuous and tegula nearly impunctate) ( Fig. 35A View Fig ) ..................................................................................................................... 7

– Tegula with dense punctures medially (i ≤ 1dp) ( Fig. 35B View Fig ) ............................................................. 8

7. Mesoscutum with dense plumose setae 0.5–1.0 OD long (all setae separated by less than half their length in lateral view) (as in Fig. 29B View Fig ); mesoscutum dark turquoise-green to olive green; retrorse lobe enlarged and wide; S8 median processs narrow and long; penis valve wide observed in lateral view ...................................................... L. aureoviride Landaverde-González & Husemann sp. nov.

– Mesoscutum with sparse plumose setae 0.5–1 OD long (most setae separated by half their length or more in lateral view, especially on posterior half) (as in Fig. 29A View Fig ); mesoscutum golden-green to brassy; retrorse lobe small; S8 median process wide; penis valve small and delicate observed in lateral view ........................................................................ L. paxtoni Landaverde-González sp. nov.

8. Mesepisternum moderately sparsely punctate at least on ventral half (i = 1–2 pd) (as in Fig. 31A View Fig ). ............................................................................................................... L. stictaspis View in CoL species complex

– Mesepisternum densely punctate (i <1 pd) (as in Fig. 31B View Fig ) ............................................................ 9

9. Mesoscutum with sparse plumose setae 0.5–1 OD long (most setae separated by half their length or more in lateral view, especially on posterior half) (as in Fig. 29A View Fig ); metapostnotum somewhat shiny, finely and weakly reticulate, with strong subparallel rugae ( Fig. 36A View Fig ) .............................................. ................................................................................... L. yucatanense Landaverde-González sp. nov.

– Mesoscutum with dense plumose setae 0.5–1 OD long (all setae separated by less than half their length in lateral view) (as in Fig. 29B View Fig ); metapostnotum shiny, with weak microsculpture and strong rugae ( Fig. 36B View Fig ) ................................................................................. L. paralepidii Gardner sp. nov.