Lasioglossum (Dialictus) torrens, 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 : 195-198

publication ID 10.5852/ejt.2020.725.1167

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scientific name

Lasioglossum (Dialictus) torrens

sp. nov.

Lasioglossum (Dialictus) torrens sp. nov.

Figs 85–86 View Fig View Fig


Females of Lasioglossum torrens sp. nov. can be recognized by the head and mesosoma mostly covered in tessellate microsculpture, frons with crowded punctures (i= 0 pd) contrasting with sparser paraocular area punctures (i ≤ 1 pd), mesepisternum moderately sparsely punctate (i <2 pd), pronotal angle about 90 degrees, T1 anterior surface shiny with acarinarial fan sparse, ocelli normal, wings infuscated with dark veins and dark hairs, and most hair pale yellow to golden. Occasionally the scopa have black hairs intermixed. They are most similar to L. decorum sp. nov. and L. hudsoniellum . Females of L. decorum sp. nov. have T1 anterior surface coriarious with acarinarial fan dense, pronotal angle obtuse, and ocelli enlarged (separated by about 0.5 OD). Females of L. hudsoniellum have the head and mesosoma mostly shiny, frons with dense but distintly separated punctures (i <1 pd), and mesepisternum densely punctate (i <1 pd).


The specific epithet ‘ torrens ’ is a Latin present participle meaning ‘scorching’, ‘roasting’, or ‘rushing’, which is sometimes applied to lava. It is a reference to the yellow, red, and smoky colouration of this species, reminiscent of lava, and the type locality near the Colima volcano. An appropriate translation would be the scorching sweat bee.

Material examined


MEXICO – Colima • ♀; Minatitlán ; 19.43247° N, 103.97724° W; 11 Oct. 2010; S. Dumesh leg.; PCYU.

[Verbatim label: MEXICO Colima Minatitlán / N19.43247 W103.97724 / 1394m 11.x.10 S. Dumesh / PCYU-MEX10-0517 // BeeBOL / CCDB-09853 H08 / BOWMT377-10 // HOLOTYPE / Lasioglossum (Dialictus) torrens Gardner and Gibbs ]



MEXICO – Colima • 1 ♀; Minatitlán ; 19.42414° N, 103.97286° W; 11 Oct. 2010; S. Dumesh leg.; PCYU GoogleMaps . – Morelos • 1 ♀; Cuernavaca ; [18.92° N, 99.22° W]; Dec. 1944; N.L.H. Krauss leg.; USNM GoogleMaps . – Sinaloa • 5 ♀♀; 11.2 km W of Santa Lucia; [23.43° N, 105.96° W]; 12 Aug. 1964; W.R.M. Mason leg.; SEMC GoogleMaps .



COLOURATION. Head and mesosoma olive green to golden-green; clypeus apical colour black to reddish brown; labrum black to reddish brown; mandible orange with black basal band and red tip; flagellum black to reddish brown dorsally, reddish brown ventrally; pronotal lobe reddish brown to orange; metasoma orange to reddish brown with dark spiracular spots on T3–4 and sometimes T2; legs reddish brown with femur-tibia joints, base and apex of tibiae, and tarsi orange; tegula orange; wing membrane infuscated, veins brown to dark brown.

PUBESCENCE. Body hair colour golden to pale yellow. Tomentum dense on gena, pronotal collar and lobe, space between pronotal lobe and tegula, metanotum medially, T2–3 basolaterally, and T4 throughout; sparse on face, metepisternum, and T5. Scutum hair thin to densely plumose. Wing hairs dark, long and dense. Acarinarial fan incomplete, very sparse. T2 fringes sparse, T3 fringes sparse.

SURFACE SCULPTURE. Clypeus punctures moderately sparse (i =1–2 pd), sculpture imbricate or weakly so in basal half, shiny apically; supraclypeal area punctures sparse (i=1–4 pd), becoming dense laterally (i ≤ 1 pd), sculpture imbricate, sometimes shiny medially; paraocular area punctures dense (i ≤ 1 pd), sculpture imbricate; frons punctures crowded (i =0 pd), sculpture shiny to imbricate; vertex punctures crowded laterally (i=0 pd), sparse medially (i =1–3 pd), sculpture shiny to imbricate; gena punctures moderately sparse (i=1–3 pd), sculpture shiny, becoming imbricate and sometimes weakly ruguloso-lineate posteriorly and ventrally; postgena sculpture imbricate, becoming shiny anteriorly; tegula punctures absent; scutum punctures dense (i ≤ 1 pd), becoming slightly sparser submedially and anteromedially (i= 1–3 pd), sculpture tessellate, sometimes becoming shiny posteromedially; scutellum punctures dense marginally and on median line (i <1 pd), sometimes finer and sparser anteriorly (i =1–2 pd), sparse submedially (i =1–3 pd), diversopunctate, sculpture shiny, sometimes becoming tessellate marginally and on median line; metanotum sculpture imbricate; metapostnotum rugae strong, anastomosing, sometimes reaching margin, sculpture imbricate to tessellate; preëpisternum sculpture rugulose; hypoepimeron punctures dense (i <1 pd), sculpture imbricate; mesepisternum punctures dense to moderately sparse (i <2 pd), sculpture imbricate; metepisternum sculpture lineate dorsally, imbricate ventrally; propodeum lateral face sculpture tessellate; propodeum posterior face sculpture tessellate; T1 anterior face sculpture shiny; T1 dorsal surface punctures fine, sparse (i =1–4 pd), absent in broad median line and large apicolateral oval patches, sculpture shiny; T2 disc punctures fine, moderately sparse (i= 1–3 pd), becoming sparser medially (i= 1–4 pd), disc sculpture shiny, becoming coriarious basally, rim punctures fine, moderately sparse (i=1–3 pd), becoming sparse (i=2–6 pd) or absent medially, rim sculpture shiny to weakly coriarious.

STRUCTURE. Face length/width ratio 0.83 (± 0.02 SD). Clypeus projecting ~67% below suborbital tangent; clypeal area length/width ratio 0.41 (± 0.02 SD); apicolateral denticles rounded knobs; supraclypeal area length/width ratio 0.72 (± 0.09 SD). Forewing with 3 submarginal cells; pronotal angle slightly obtuse, nearly right-angled; tegula shape normal. Intertegular distance 0.97 (± 0.02 SD) mm. Scutum length/ width ratio 0.8 (± 0.02 SD); scutum/scutellum length ratio 3.17 (± 0.13 SD); scutellum/metanotum length ratio 1.34 (± 0.07 SD); metanotum/metapostnotum length ratio 0.74 (± 0.04 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. T2 depressed apical rim length less than 50% of segment. (n=8)




Sinaloa, Colima, and Morelos ( Fig. 86 View Fig ).

DNA barcodes

Four sequences available (BOLD process IDs: BOWMT260-10, BOWMT377-10, BOWMT400-10, BOWMT401-10; BIN: BOLD:AAU5301). Lasioglossum torrens sp. nov. differs from all other western red-tailed L. ( Dialictus ) by 7 fixed substitutions: 120(A), 135(C), 177(C), 192(C), 231(C), 301(G), and 324(A) (Supplementary file 4).


Rare. Only known from three localities in southern and central Mexico. Lasioglossum torrens sp. nov. is probably mostly Neotropical.


USA, Washington D.C., National Museum of Natural History, [formerly, United States National Museum]


USA, Kansas, Lawrence, University of Kansas, Snow Entomological Museum


Smithsonian Institution, National Museum of Natural History


University of Kansas - Biodiversity Institute













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