Lasioglossum (Dialictus) tessellatosum, Gardner & Gibbs, 2020

Gardner, Joel & Gibbs, Jason, 2020, The ‘ red-tailed’ Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic, European Journal of Taxonomy 725, pp. 1-242 : 186-191

Lasioglossum (Dialictus) tessellatosum sp. nov.

urn:lsid:zoobank.org:act:70FF0DE1-A7C4-4019-A346-41F5D5F6C6F4

Figs 81–83 , 93A , 94A

Diagnosis

Females of Lasioglossum tessellatosum sp. nov. can be recognized by the head and mesosoma with very strong tessellate to reticulate microsculpture often obscuring the punctures, scutum with sparse punctures (i= 1–4 pd) abruptly becoming denser laterad of the parapsidal lines (i <2 pd), frons with relatively large and crowded punctures (i =0 pd), T1 anterior surface shiny, metasomal terga lacking tomentum, and T2 without dark spiracular spots. They are most similar to L. meteorum sp. nov. Females of L. meteorum sp. nov. have the frons with finer and distinctly separated punctures, scutum with slightly weaker (but still strong) microsculpture, T1 anterior surface coriarious, and metasomal terga with some sparse tomentum.

Males of L. tessellatosum sp. nov. can be recognized by the scutum tessellate with sparse punctures (i =1–4 pd) abruptly becoming dense laterad of the parapsidal lines (i ≤ 1 pd), mesepisternum tessellate and densely punctate (i ≤ 1 pd), clypeus densely punctate (i ≤ 1 pd) with very narrow black to brown apical band, frons very dull and densely punctate (i=0 pd), and metasomal terga with broad impunctate rims. They are most similar to L. meteorum sp. nov. Males of L. meteorum sp. nov. have the clypeus and mesepisternum sparsely punctate (i = 1–4 pd), scutum and mesepisternum with weaker microsculpture, and clypeus without any non-metallic apical band.

Etymology

The specific epithet tessellatosum is formed from the Latin adjective ‘ tessellatum ’ (‘inlaid with small square stones’, a mosaic) and the suffix ‘ -osum ’, indicating fullness or abundance. It refers to the very strong microsculpture of this species. An appropriate translation would be the tessellate sweat bee.

Material examined

Holotype

MEXICO – Chiapas • ♀; Villa Corzo ; 16.23° N, 93° W; 623 m a.s.l.; 3 Feb. 2016; Philippe Sagot leg.; ECOAB.

[Verbatim label: ECOAB.79796 / Mex., Chis / Villa Corzo / 632 m / 16,23 N; 93 W / 2/3/2016 / Philippe Sagot // BOLD / DLIII117-18 / gard0051-MX // HOLOTYPE / Lasioglossum (Dialictus) tessellatosum Gardner and Gibbs ]

Paratypes

GUATEMALA – Huehuetenango • 1 ♀; San Antonio Hulsta, Cajuil ; 15.63746° N, 91.78722° W; 1026 m a.s.l.; 5 Jul. 2010; Mario leg.; ex Coffea ; ECOAB . – Quetzaltenango • 1 ♀; 5 mi. E of Coatepeque; [14.7° N, 91.8° W]; 4 Jul. 1965; Slobodchikoff and Raske leg.; EMEC .

MEXICO – Chiapas • 1 ♀; Jaltenango Paz ; 15.82° N, 92.79° W; 692 m a.s.l.; 3 Feb. 2016; Philippe Sagot leg.; ECOAB • 1 ♀; La Trinitaria , San Francisco de Asis ; 16.0232° N, 92.0455° W; 768 m a.s.l.; 16 Nov. 2011; Philippe Sagot leg.; ECOAB • 1 ♀; Mapastepec , Camino A Santa Rosa ; 15.3405° N, 92.5757° W; 24 Feb. 2005; R. Ayala, R. Vandame and M. Guzmán leg.; ECOAB . – Chihuahua • 3 ♀♀; Santo Niño ; [27° N, 107° W]; 31 Aug. 1968; T.A. Sears, R.C. Gardner and C.S. Glaser leg.; UCDC . – Hidalgo • 1 ♀; 14.5 km NW of Cardonal; [20.73° N, 99.15° W]; 1850 m a.s.l.; 13 Jul. 1990; W. Bell, D. Conlon and R.L. Minckley leg.; ex Agave ; SEMC . – Jalisco • 3 ♀♀; Careyes ; 19.4289° N, 105.0274° W; 12 Feb.–19 Mar. 1997; F.D. Parker leg.; BBSL • 1 ♀, 1 ♂; Guadalajara ; [20.65° N, 103.35° W]; Crawford leg.; USNM • 1 ♀; Puerto Vallarta ; 20.6214° N, 105.226° W; 25 Jan. 1984; G.E. Bohart leg.; BBSL . – Morelos • 1 ♀; 7.3 mi. S. Yautepec; [18.78° N, 99.06° W]; 914 m a.s.l.; 15 Aug. 1962; Marston and Naumann leg.; SEMC • 1 ♀; same location as for preceding; 16 Aug. 1962; Ordway and Naumann leg.; SEMC • 1 ♀; Cañon de Lobos ; [18.86° N, 99.12° W]; 23–30 Mar. 1961; C. Benschoter leg.; UMSP . – Veracruz • 1 ♂; Orizaba ; [18.85° N, 97.1° W]; Crawford leg.; USNM .

Description

Female

COLOURATION. Head and mesosoma blue-green to golden-green; clypeus apical colour black, reddish brown, or orange; labrum reddish brown to orange; mandible orange with black base and red tip; flagellum black to dark reddish brown dorsally, slightly lighter ventrally; pronotal lobe black, reddish brown, or orange; metasoma orange with T1 basal half and T5 sometimes black to brown, dark spiracular spots on T3–4; legs reddish brown with femur-tibia joints, tarsi, and sometimes tibiae mostly orange; tegula orange; wing membrane lightly infuscated, veins with subcosta dark brown, otherwise light brown to pale amber.

PUBESCENCE. Body hair colour white to pale yellow. Tomentum dense on pronotal collar and lobe, space between pronotal lobe and tegula, and metepisternum ventral half; sparse on paraocular area, vertex, gena, and metanotum. Scutum hair thin. Wing hairs dark or light, short and dense. Acarinarial fan incomplete, sparse. T2 fringes sparse, T3 fringes sparse.

SURFACE SCULPTURE. Clypeus punctures dense (i ≤ 1 pd), small on basal margin, otherwise large and somewhat irregular, sculpture tessellate in basal half, shiny apically; supraclypeal area punctures dense marginally (i ≤ 1 pd), sparse medially (i=1–3 pd), sculpture tessellate, sometimes shiny medially; paraocular area punctures dense (i <1 pd), often obscure, sculpture shiny ventrally and in narrow line adjacent to compound eye, otherwise tessellate; frons punctures crowded (i=0 pd), often indistinct, sculpture reticulate or ruguloso-punctate; vertex punctures crowded laterally (i= 0 pd), often obscure, absent medially, sculpture shiny or weakly tessellate; gena punctures fine, moderately dense (i=1–2 pd), sculpture shiny; postgena sculpture shiny to tessellate, becoming ruguloso-lineate posteriorly; tegula punctures absent; scutum punctures sparse (i =1–4 pd), usually abruptly becoming dense to moderately dense laterad of parapsidal line (i <2 pd), sculpture finely reticulate; scutellum punctures dense marginally and on median line (i <1 pd), sparse submedially (i=1–2 pd); minute and hardly evident in anterior half, larger and more distinct posteriorly, sculpture finely reticulate; metanotum sculpture finely reticulate and moderately densely punctate (i=1–2 pd); metapostnotum rugae weak or moderately strong, anastomosing, reaching about halfway to margin, sculpture tessellate; preëpisternum sculpture finely reticulate and densely but obscurely punctate (i ≤ 1 pd); hypoepimeron punctures dense (i <1 pd), obscure, sculpture finely reticulate; mesepisternum punctures dense dorsally (i ≤ 1 pd), becoming sparse ventrally (i =1–2 pd), mostly obscured by microsculpture, sculpture finely reticulate; metepisternum sculpture ruguloso-lineate dorsally, becoming rugulose ventrally; propodeum lateral face sculpture tessellate; propodeum posterior face sculpture tessellate; T1 anterior face sculpture shiny; T1 dorsal surface punctures very fine and sparse (i=2–6 pd), absent in median line and small apicolateral oval patches, sculpture shiny; T2 disc punctures fine, moderately sparse (i =1–3 pd), disc sculpture shiny to weakly coriarious, rim punctures shallow and obscure, moderately sparse (i =1–3 pd), rim sculpture weakly coriarious.

STRUCTURE. Face length/width ratio 0.81 (± 0.02 SD). Clypeus projecting ~50% below suborbital tangent; clypeal area length/width ratio 0.43 (± 0.01 SD); apicolateral denticles rounded knobs; supraclypeal area length/width ratio 0.66 (± 0.05 SD). Forewing with 3 submarginal cells; pronotal angle slightly obtuse, nearly right-angled; tegula shape normal. Intertegular distance 1 (± 0.11 SD) mm. Scutum length/width ratio 0.84 (± 0.04 SD); scutum/scutellum length ratio 2.92 (± 0.13 SD); scutellum/metanotum length ratio 1.61 (± 0.18 SD); metanotum/metapostnotum length ratio 0.62 (± 0.08 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. T2 depressed apical rim length less than 50% of segment. (n =10)

Male

COLOURATION. Head and mesosoma blue-green to olive green; clypeus apical colour narrowly black to reddish brown; labrum black to reddish brown; mandible brown with black basal band and red tip;

flagellum reddish brown; pronotal lobe reddish brown; metasoma black to reddish brown; legs reddish brown; tegula brown; wing membrane lightly infuscated, veins dark brown.

PUBESCENCE. Body hair colour pale yellow to white. Tomentum dense in space between pronotal lobe and tegula; sparse on face below eye emargination, gena anteriorly, and pronotal angle and lobe. Scutum hair thin. Sterna hair moderately long (1–2 OD), moderately plumose, sparse and erect. Wing hairs dark, short and dense.

SURFACE SCULPTURE. Clypeus punctures dense (i ≤ 1 pd), diversopunctate, sculpture shiny; supraclypeal area punctures moderately sparse (i= 1–2 pd), obscure, sculpture tessellate; paraocular area punctures dense (i ≤ 1 pd), sculpture shiny; frons punctures crowded (i= 0 pd), sculpture reticulate-rugulose, becoming shiny to imbricate laterally; vertex punctures crowded laterally (i=0 pd), dense (i ≤ 1 pd) and obscure medially, sculpture imbricate to finely reticulate; gena punctures moderately sparse (i=1–2 pd), sculpture shiny, becoming imbricate posteriorly and ventrally; postgena sculpture shiny, becoming imbricate posteriorly and laterad of hypostomal carina; tegula punctures absent; scutum punctures sparse (i =1–4 pd), abruptly becoming dense laterad of parapsidal lines (i ≤ 1 pd), sculpture tessellate to finely reticulate; scutellum punctures dense marginally and on median line (i ≤ 1 pd), sparse submedially (i =1–4 pd), sculpture tessellate to finely reticulate, becoming shiny submedially; metanotum sculpture finely reticulate, sometimes becoming shiny medially, and moderately sparsely punctate (i=1–2 pd); metapostnotum rugae strong, anastomosing, not reaching margin, sculpture imbricate; preëpisternum sculpture areolate-rugulose to rugose; hypoepimeron punctures dense (i <1 pd), sculpture tessellate to finely reticulate; mesepisternum punctures dense (i ≤ 1 pd), sculpture tessellate to finely reticulate; metepisternum sculpture lineate dorsally, areolate ventrally; propodeum lateral face punctures obscure, sculpture tessellate to weakly rugulose; propodeum posterior face sculpture shiny, becoming imbricate and densely punctate laterally (i <1 pd); T1 anterior face sculpture shiny; T1 dorsal surface punctures sparse (i=1–4 pd), absent or very sparse in large apicolateral oval patches and on rim, sculpture shiny; T2 disc punctures sparse (i=1–3 pd), disc sculpture shiny, rim punctures absent, rim sculpture shiny.

STRUCTURE. Face length/width ratio 0.78 (± 0 SD). F1:pedicel length ratio 0.9 (± 0.14 SD); F2:F1 length ratio 2.13 (± 0.18 SD); F2 length/width ratio 1.49 (± 0.1 SD); F9 length/width ratio 1.23 (± 0.06 SD). Forewing with 3 submarginal cells; pronotal angle slightly obtuse, nearly right-angled; tegula shape normal. Intertegular distance 0.86 (± 0.07 SD) mm. Scutum length/width ratio 0.85 (± 0.01 SD); scutum/ scutellum length ratio 2.61 (± 0.12 SD); scutellum/metanotum length ratio 1.58 (± 0.08 SD); metanotum/ metapostnotum length ratio 0.66 (± 0.08 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. (n=2)

GENITALIA. Not examined.

Range

Tropics and transition zones from Chihuahua south to Guatemala ( Fig. 83 ).

Floral records

ASPARAGACEAE Juss. Agave L. • RUBIACEAE Juss. Coffea L.

DNA barcodes

Two sequences available (BOLD process IDs: BBLEG173-17, DLIII117-18; BINs: BOLD:ADB1211, BOLD:ADH0657). Lasioglossum tessellatosum sp. nov. differs from all other western red-tailed L. ( Dialictus ) by 2 fixed substitutions: 45(A) and 381(T) (Supplementary file 4).

Remarks

Lasioglossum tessellatosum sp. nov. is extremely widespread throughout Mexico and occurs at least as far south as western Guatemala, but seems to be replaced by L. meteorum sp. nov. on the Yucatan Peninsula. It is most commonly found at high elevation in southern Mexico, with a disjunct series of specimens from Santo Niño, Chihuahua. The exact location of this ‘Santo Niño’ is not known (several locations in Chihuahua are known by that name), but somewhere in the less arid western part of the state is likely.

Figures

Fig. 81. Lasioglossum (D.) tessellatosum sp. nov., ♀. A. Dorsal habitus. B. Face. C. Lateral habitus. D. Propodeum and metasoma. Scale bars: 1 mm.

Fig. 82. Lasioglossum (D.) tessellatosum sp. nov., ♂. A. Dorsal habitus. B. Lateral habitus. C. Face. D. Metasoma. Scale bars: 1 mm.

Fig. 83. Georeferenced collection records of Lasioglossum (D.) tessellatosum sp. nov. (black squares) and predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence.

Fig. 93. Mesoscutum. A. Lasioglossum (D.) tessellatosum sp. nov., ♀, with strong microsculpture and sparse punctures. B. L. (D.) droegei Gibbs, 2009, ♂, with strong microsculpture and dense punctures. C. L. (D.) cactorum sp. nov., ♀, shiny and sparsely punctate. Scale bars: 0.5 mm.

Fig. 94. Variation in frons punctation. A. Lasioglossum (D.) tessellatosum sp. nov., ♀, reticulatepunctate to ruguloso-punctate with crowded punctures. B. L. (D.) meteorum sp. nov., ♀, fine and dense but distinctly separated punctures. C. L. (D.) julipile sp. nov., ♀, moderately sparsely punctate. D. L. (D.) perditum sp. nov., ♀, very sparsely punctate. Scale bars: 0.5 mm.