Lasioglossum (Sphecodogastra) iridescens, Hettiarachchi & Gibbs, 2024

Hettiarachchi, Thilina & Gibbs, Jason, 2024, A problematic species complex for Lasioglossum subgeneric diagnostics in North America (Hymenoptera: Halictidae), Zootaxa 5404 (1), pp. 206-235 : 210-217

Lasioglossum (Sphecodogastra) iridescens sp. nov.

Figs 3–7 , 8A , 9A , 10A , 11A, 11B

Diagnosis. Females of L. iridescens can be recognised by the combination of head short [Face length/width ratio = 0.80 (± 0.02 SD)]; presence of oily metallic sheen on mesoscutum and mesoscutellum ( Fig. 8 ) (non-metallic in all other North American L. ( Sphecodogastra ); propodeum with lateral carinae reaching dorsal margin and oblique carina very strong; inner metatibial spur pectinate, basal branch longer than width of rachis ( Figs. 11A, 11B ); mesepisternum area with weakly rugose ventrally and reticulate-rugose to punctate dorsally ( Fig. 9A ); mesoscutum shiny, becoming tessellate to imbricate anteromedially.

Lasioglossum iridescens is quite similar to the other two species described herewith. The other two species have the basal branch on the inner metatibial spur shorter than or subequal to the width of the rachis ( Figs. 11C–11F ). Lasioglossum iridescens has the mesepisternum with reticulate-rugose surface structure with large puncture dorsally ( Fig. 9A ) whereas the other two species have the mesepisternum rugose to reticulate-rugose mostly throughout ( Figs. 9B, 9C ), with punctation less distinct.

Lasioglossum silveirai sp. nov. has sparser punctures on the supraclypeal area, mesoscutum, and mesoscutellum ( Figs. 8C, 8D , 10C ). All three species have an oily metallic sheen on the mesoscutum ( Figs. 8A, 8B, 8C ), but in L. silveirai this may be less evident in some individuals ( Fig 8D ). T 1 punctures appear deeper in L iridescens compared to others.

Males of L. iridescens can be recognised by the combination of head short [Face length/width ratio 0.89 (± 0.03 SD)]; clypeus with yellow on distal half ( Fig. 4B ); mandible short, reaching near opposing clypeal angle; F2 long, nearly equal to scape ( Fig. 4B ); thorax with scattered tomentum; propodeum lateral carinae not reaching dorsal margin, oblique carina absent ( Fig. 4D ); metasomal sterna nearly bare, hairs present but very short ( Fig. 4C ). The retrorse lobe is long and broad, covered in short hairs, curved medially, which gives it a unique shape ( Fig. 5 ). In combination with the short gonostylus with short setae, the genitalia should separate L. iridescens from most other L. ( Sphecodogastra ). Males of other two species described here are unknown.

Males of other L. ( Sphecodogastra ) lack the combination of thoracic tomentum, metasomal sterna bare, and the genital characters. Most L. ( Sphecodogastra ) lack the tomentum and have elongate gonostyli, usually with elongate setae. Onagraceae-specialist L. ( Sphecodogastra ) may have similar pilosity and genitalia but have more evident sternal setae. Lasioglossum (Evylaeus) amicus (Cockerell) has an overall similar appearance, but again differs in the sternal setae, and the structure of the genitalia.

Etymology. The specific epithet refers to the iridescent colouration of the new species.

Holotype. USA — California • ♀; Riverside Co., 1.5 mi. W of Perris [33. 7820° N, 117.2547° W]; 1 April 1936; ex Salvia mellifera ; P.H. Timberlake leg.; UCRC, GIBBS- 12353. [Verbatim label: 1 ½ miles W. / Perris, Cal. // on Salvia mellifera // Timberlake Coll. / Apr 1, 36 // Lasioglossum GIBBS- 12353 // Holotype / Lasioglossum (Sphecodogastra) iridescens Hettiarachchi and Gibbs ]

Paratypes. MEXICO — Baja California • 1 ♀; Ejido Piedras Gordas, Ensenada; 31.9369° N, 116.33833° W; 13 May 2021; A. Castañeda leg.; ex yellow pan trap; A. Castañeda Research Collection. USA — Arizona • 1 ♀; Pinal Co., Ray; [33.183° N, 110.998° W]; 28 Mar 1961; J.C. Bequaert leg.; ASUHIC • 1 ♀; Pinal Co., Superior, Boyce Thompson Arboretum; [33.2678° N, 111.1583° W]; 03 May 1953; G.D. Butler leg.; ex Thistle; ASUHIC • 1 ♀; ibid.; 03 May 1953; G.D. Butler leg.; ex Poppy; ASUHIC • 1 ♀; ibid.; 03 May 1953; G.D. Butler leg.; ex Opuntia ; ASUHIC • 1 ♀; ibid.; 04 Jun 1962; F. Werner, J. Bequaert leg.; ASUHIC— California • 1 ♀; Kern Co., 1 mi. S of Red Rock Canyon; [35.3590° N, 117.9814° W]; 01 Apr 1959; G.I. Stage leg.; ex Tamarix gallica ; UCRC • 1 ♀; Kern Co., Mojave-Deep Creek; [34.2712° N, 117.1307° W]; 26 Apr 1936; P. M. Opitz leg.; UCRC • 1 ♀; Los Angeles Co., 5 mi. S of Pearblossom; [34.4336° N, 117.9094° W]; 12 May 1956; E.G. Linsley leg.; EMEC • 1 ♀; Los Angeles Co., Littlerock—Palmdale Dam; [34.4856° N, 118.0247° W]; elev. 1036.3 m.; 02 May 1970; R. R. Snelling leg.; LACM • 1 ♂; Los Angeles Co., Vincent; [34.098242° N, 117.9228° W]; 04 Aug 1952; P.H. Timberlake leg.; ex flying about junipers; UCRC • 3 ♂♂; Riverside Co., 1.5 mi. W of Perris; [33.7820° N, 117.2547° W]; 13 Jun 1938; Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 1♀; ibid.; 07 Apr 1940; P.H. Timberlake leg.; ex Salvia columbariae ; UCRC • 1 ♀; ibid.; 04 May 1940; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 18 May 1940; P.H. Timberlake leg.; ex either Calylophus sp. or Camissonia sp. (verbatim: nr. Oenothera ); nr. Oenothera ; UCRC • 1 ♀; ibid.; 29 May 1940; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 2 ♂♂; ibid.; 21 Jun 1940; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 1 ♂; ibid.; 17 May 1941; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; Riverside Co., 2 mi. W of Perris; [33.7824° N, 117.2639° W]; 19 May 1936; P.H. Timberlake leg.; ex Lasthenia gracilis ; UCRC • 1 ♀; Riverside Co., 3 mi. NE of Moreno; [33.9607° N, 117.2045° W]; 12 Apr 1963; J. Powell leg.; UCRC • 1 ♀; Riverside Co., 3 mi. W of Perris; [33.7821° N, 117.28° W]; 16 Apr 1939; P.H. Timberlake leg.; ex Lasthenia gracilis ; UCRC • 1 ♀; Riverside Co., 4 mi. W of Perris; [33.7822° N, 117.2981° W]; 10 Apr 1946; P.H. Timberlake leg.; ex Platystemon californicus Benth. ; UCRC • 1 ♀; Riverside Co., 4.5 mi. W of Perris; [33.7821° N, 117.3068° W]; 27 May 1946; P.H. Timberlake leg.; ex Gilia achilleifolia subsp. multicaulis ; UCRC • 1 ♀; ibid.; 27 May 1946; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; Riverside Co., 5 mi. S of Sage; [33.5081° N, 116.9321° W]; 16 Apr 1965; C. A. Toschi leg.; UCRC • 2 ♀♀; ibid.; 16 Apr 1965; J. Powell leg.; UCRC • 1 ♀; Riverside Co., Aguanga; [33.4422 ° N, 116.8669° W]; elev. 605 m.; 09 May 1936; P.H. Timberlake leg.; ex Prosopis sp. ; UCRC • 1 ♀; Riverside Co., Lake Elsinore; [33.6733° N, 117.3361° W]; elev. 440 m.; 13 Apr 1965; C. A. Toschi leg.; UCRC • 1 ♀; Riverside Co., Gavilan Hills; [33.7944° N, 117.3558° W]; elev. 620 m.; 09 May 1936; P.H. Timberlake leg.; ex Prosopis sp. ; UCRC • 7 ♀♀; ibid.; 19 May 1936; P.H. Timberlake leg.; ex Rhus trilobata ; UCRC • 1 ♂; ibid.; 29 May 1936; P.H. Timberlake leg.; ex Keckiella antirrhinoides ; UCRC • 1 ♀; ibid.; 02 May 1937; P.H. Timberlake leg.; ex Salix ; UCRC • 2 ♀♀; ibid.; 02 Mar 1938; P.H. Timberlake leg.; ex Salix lasiolepis ; UCRC • 1 ♀; ibid.; 16 Mar 1938; P.H. Timberlake leg.; ex Ceanothus crassifolius ; UCRC • 1 ♀; ibid.; 16 Mar 1938; P.H. Timberlake leg.; ex Salix laevigata ; UCRC • 1 ♀; ibid.; 01 Apr 1938; P.H. Timberlake leg.; ex Rhus trilobata ; UCRC • 1 ♀; ibid.; 01 Apr 1938; P.H. Timberlake leg.; ex Plagiobothrys collinus ; UCRC • 1 ♀; ibid.; 08 Apr 1938; P.H. Timberlake leg.; ex Rhus trilobata ; UCRC • 3 ♀♀; ibid.; 17 Apr 1938; P.H. Timberlake leg.; ex Lasthenia coronaria ; UCRC • 1 ♀; ibid.; 17 Apr 1938; P.H. Timberlake leg.; ex Rhus trilobata ; UCRC • 1 ♀; ibid.; 16 May 1938; P.H. Timberlake leg.; ex Salix laevigata ; UCRC • 1 ♀; ibid.; 21 Jun 1938; P.H. Timberlake leg.; ex Eriastrum virgatum ; UCRC • 1 ♀; ibid.; 24 Jun 1938; P.H. Timberlake leg.; ex Eriastrum virgatum ; UCRC • 1 ♀; ibid.; 07 Apr 1939; P.H. Timberlake leg.; ex Camissonia contorta ; UCRC • 1 ♀; Riverside Co., Gavilan Hills; [33.7944° N, 117.3558° W]; elev. 620 m.; ex flying near ground; 07 Apr 1939; P.H. Timberlake leg.; UCRC • 1 ♀; Riverside Co., Gavilan Hills; [33.7944° N, 117.3558° W]; elev. 620 m.; 07 Apr 1939; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 16 Apr 1939; P.H. Timberlake leg.; ex Camissonia contorta ; UCRC • 1 ♀; ibid.; 16 Apr 1939; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 07 Apr 1940; P.H. Timberlake leg.; ex Salvia columbariae ; UCRC • 1 ♀; ibid.; 14Apr 1940; P.H. Timberlake leg.; ex Salvia mellifera ; UCRC • 1 ♀; ibid.; 14 Apr 1940; P.H. Timberlake leg.; ex Salvia columbariae ; UCRC • 1 ♀; ibid.; 14 Apr 1940; P.H. Timberlake leg.; ex Chaenactis glabriuscula ; UCRC • 2 ♀♀; ibid.; 14 Apr 1940; P.H. Timberlake leg.; ex Minuartia douglasii ; UCRC • 1 ♀; ibid.; 14 Apr 1940; P.H. Timberlake leg.; ex Salvia mellifera ; UCRC • 2 ♀♀; ibid.; 18 Apr 1940; P.H. Timberlake leg.; ex Salvia columbariae ; UCRC • 2 ♀♀; ibid.; 18 Apr 1940; P.H. Timberlake leg.; ex Lasthenia gracilis ; UCRC • 2 ♀♀; ibid.; 12 May 1950; P.H. Timberlake leg.; ex Hirschfeldia incana ; UCRC • 1 ♀; ibid.; 12 May 1950; P.H. Timberlake leg.; ex Erysimum cheiranthoides ; UCRC • 6 ♂♂; ibid.; 12 May 1950; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 1 ♀; ibid.; 16 May 1950; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 5 ♂♂; ibid.; 09 Jun 1950; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 1 ♀; ibid.; 14 Apr 1959; P.H. Timberlake leg.; ex Phacelia distans ; UCRC • 1 ♀; ibid.; 24 June 1938 to 24 July 1938; P.H. Timberlake leg.; ex Eriastrum virgatum ; UCRC • 2 ♂♂; ibid.; 24 June 1938 to 24 July 1938; P.H. Timberlake leg.; ex Adenostoma fasciculatum ; UCRC • 1 ♀; Riverside Co., Lake Mathews; [33.825° N, 117.500° W]; elev. 260 m.; 11 Apr 1954; P.H. Timberlake leg.; ex Platystemon californicus ; UCRC • 2 ♀♀; Riverside Co., Seven Level Hill,, ~10 Rd. mi. SW of Palm Desert; [33.6067° N, 116.4272° W]; elev. 1160 m.; 12 Apr 1963; J. Powell leg.; UCRC • 22 ♂♂; Riverside Co., Spring Crest, Ribbonwood; [33.5683° N, 116.4897° W]; elev. 1400 m.; 02 Jul 1936; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 1 ♂; Riverside Co., Spring Crest, Ribbonwood; [33.5683° N, 116.4897° W]; elev. 1400 m.; 13 Jun 1938; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 1♀; Riverside Co., Riverside; [33.9556° N, 117.3722° W]; elev. 290 m.; 22 Feb 1937; P.H. Timberlake leg.; ex Salix lasiolepis ; UCRC • 2 ♀♀; Riverside Co., Riverside; [33.9556° N, 117.3722° W]; elev. 290 m.; 17Apr 1925; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1♀; ibid.; 14 May 1925; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 14 May 1925; P.H. Timberlake leg.; ex Encelia farinosa ; UCRC • 1 ♀; ibid.; 24 May 1925; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 06 Apr 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 2 ♀♀; ibid.; 07 Apr 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 20 Apr 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 27 Apr 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 08 May 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 23 May 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 24 May 1927; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 30 Mar 1928; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 31 May 1928; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 2 ♀♀; ibid.; 28 Mar 1931; P.H. Timberlake leg.; ex Eschscholzia californica ; UCRC • 1 ♀; ibid.; 16 May 1932; P.H. Timberlake leg.; ex Cylindropuntia californica ; UCRC • 1 ♀; ibid.; 29 Mar 1934; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 15 May 1934; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 10 Apr 1935; P.H. Timberlake leg.; ex Lasthenia gracilis ; UCRC • 1 ♀; ibid.; 10 Apr 1935; P.H. Timberlake leg.; ex Phacelia minor ; UCRC • 1 ♀; ibid.; 31 Mar 1939; P.H. Timberlake leg.; ex Phacelia minor ; UCRC • 1 ♀; ibid.; 30 Apr 1939; P.H. Timberlake leg.; ex Lasthenia coronaria ; UCRC • 1 ♀; ibid.; 28 Feb 1940; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 07 May 1940; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 08 May 1940; P.H. Timberlake leg.; ex Cryptantha intermedia ; UCRC • 1 ♀; ibid.; 27 May 1945; P.H. Timberlake leg.; ex Senecio californicus ; UCRC • 1 ♀; ibid.; 14 Apr 1952; P.H. Timberlake leg.; ex Gilia achilleifolia subsp. multicaulis ; UCRC • 1 ♀; Riverside Co., Sage; [33.5081° N, 116.9321° W]; 15 Apr 1965; J. Doyen leg.; UCRC • 1 ♀; San Bernardino Co., Kramer Hills; [34.8967° N, 117.5086° W]; elev. 920 m.; 16 Apr 1957; P.H. Timberlake leg.; ex Malacothrix californica ; UCRC • 1 ♀; ibid.; 25 Apr 1957; G.I. Stage leg.; UCRC • 1 ♀; ibid.; 25 Apr 1957; P.D. Hurd leg.; ex Amsinckia tessellata ; UCRC • 1 ♀; ibid.; 25 Apr 1957; P.D. Hurd leg.; ex Camissonia campestris subs p. campestris ; UCRC • 1 ♀; ibid.; 25 Apr 1957; P.D. Hurd leg.; ex Mentzelia micrantha ; UCRC • 1 ♀; ibid.; 25 Apr 1957; P.D. Hurd leg.; ex Gilia latiflora subsp. davyi ; UCRC • 1 ♀; ibid.; 26 Apr 1957; P.H. Timberlake leg.; ex either Calylophus sp. or Camissonia sp. (verbatim: Oenothera sp. ); UCRC • 1 ♀; ibid.; 26 Apr 1957; P.H. Timberlake leg.; ex Coreopsis ; UCRC • 1 ♀; San Bernardino Co., Lytle Creek; [34.2611° N, 117.4992° W]; elev. 1050 m.; 04 Jul 1925; P.H. Timberlake leg.; ex Eriogonum fasciculatum ; UCRC • 13 ♀♀; Tulare Co., 2 mi. E of Johnsondale; [35.9699° N, 118.4984° W]; 27 Apr 1964; J. Powell leg.; ex Prunus subcordata ; UCRC • 33 ♀♀; ibid.; 27 Apr 1964; C. A. Toschi leg.; UCRC • 18 ♀♀; ibid.; 27 Apr 1964; C. A. Toschi leg.; ex Prunus subcordata ; UCRC • 1 ♀; ibid.; 27 Apr 1964; J. Powell leg.; ex Arctostaphylos ; UCRC • 2 ♀♀; ibid.; 27 Apr 1964; C. A. Toschi leg.; ex Salix ; UCRC • 5 ♀♀; ibid.; 27 Apr 1964; P. Rude leg.; ex Prunus subcordata ; UCRC • 5 ♀♀; ibid.; 27 Apr 1964; P. Rude leg.; ex Salix ; UCRC

Description

Female. Length 5.64 (± 0.40 SD) mm. Head length 1.56 (± 0.06 SD) mm. Head width 1.67 (± 0.06 SD) mm. Wing length 4.28 (± 0.21 SD) mm. (n=16)

Colouration. Head and mesosoma dark brown to black, mesoscutum and mesoscutellum with an oily metallic sheen mostly with a green reflection and some with a green-purple mixture. Clypeus apex reddish brown. Labrum reddish brown. Mandible brown basally, light brown apically with reddish brown apex. Flagellum brown dorsally, light brown ventrally. Pronotal lobe brown to reddish brown. Tegula yellowish brown. Wing membrane hyaline, faintly dusky,veins with subcosta brown, otherwise honey-coloured. Legs brown. Metasoma brown to black, apical margins reddish brown to narrowly testaceous.

Pubescence. Setae off-white. Tomentum dense on pronotal angle and lobe, space between pronotal lobe and tegula, T 2– T 3 basolaterally; moderately dense on metanotum anterior margin; scattered on T 4– T 5; partially obscuring metepisternum. Head and mesosoma with mostly sparse pilosity, composed of highly plumose setae with very short fine setae intermixed. Lateral surface of propodeum with sparse erect setae; plumose patch on anterior dorsal area; very short fine hairs intermixed. Metafemoral scopa with dense plumose hairs. Wing hairs pale. T 1 with sparse erect setae.

Surface sculpture. Clypeus shiny, becoming imbricate basally; punctures large, irregularly spaced (IS < PD) on apical third, smaller and denser on near basal margin (IS <1 PD). Supraclypeal area mostly imbricate; punctures dense mostly throughout (IS ≤ 1 PD). Paraocular area reticulate; punctures dense (IS ≤ 1 PD) to crowded (IS = 0 PD). Frons punctate-reticulate; punctures crowded (IS = 0 PD) or dense (IS <1 PD). Vertex imbricate laterally, strongly so medially; punctures absent or obscure. Gena shiny dorsally, becoming finely lineate ventrally; punctures fine, sparse (IS = 2–4 PD). Postgena shiny, becoming tessellate posteriorly. Tegula mostly shiny and impunctate except the base. Tegula base imbricate and diversopunctate with sparse punctures (IS = 1–3 PD). Mesoscutum shiny, becoming tessellate to imbricate anteromedially; punctures large and small intermixed, mostly dense on marginally and on median line (IS <1 PD), little sparser submedially, becoming shallow and indistinct anteromedially. Punctures mesad of parapsidal line sparser (IS = 1–3 PD) than laterad of parapsidal line (IS = 1–2 PD), and becoming closer near medial line (IS ≤ 1 PD). Mesoscutellum shiny; punctures dense marginally and on median line (IS ≤ 1 PD), sparser submedially (IS = 2–4 PD), diversopunctate. Metanotum shiny and becoming weakly rugulose laterally, crowdedly punctate medially (IS ≤ 1 PD). Metapostnotum rugae strong, anastomosing, reaching at the middle of posterior margin; sculpture shiny to imbricate. Preëpisternum reticulate-rugose to rugose. Hypoepimeron shiny, becoming weakly rugulose ventrally; punctures sparse (IS = 1–3 PD) anteriorly, becoming dense (IS <1 PD) or obscure posteriorly, and there are scattered very minute punctures. Mesepisternum weakly rugose ventrally and reticulate-rugose to punctate dorsally; punctures dense (IS <1 PD) in dorsal punctate area. Metepisternum ruguloso-lineate dorsally, imbricate ventrally. Propodeum lateral face imbricate anteriorly and dorsally, otherwise tessellate; posterior face tessellate. T 1 anterior face shiny, punctures small and very sparse; T 1 dorsal surface shiny, becoming weakly coriarious on rim, punctures small, sparse (IS = 1–4 PD), very sparse in large subapicolateral boss, and absent on rim. Usually, punctures appear deeper in this species compared to others. T 2 disc imbricate to coriarious; punctures moderately dense basally (IS = 1–2 PD), becoming sparse apically (IS = 1–3 PD); rim coriarious; rim punctures absent (short hairs present but these not arising from distinct punctures).

Structure. Face length/width ratio 0.80 (± 0.02 SD). Eyes convergent below [UOD/LOD ratio 1.07 (± 0.02 SD)]. Clypeus projecting ~63% below suborbital tangent; clypeal area length/width ratio 0.83 (± 0.08 SD). Gena narrower than eye. Protibial spur with apical serrations quite longer than length to width of malus. Inner metatibial spur pectinate, teeth 3–4, basal teeth longer than width of rachis ( Figs. 11A, 11B ). Intertegular span 1.18 (± 0.06 SD) mm. Distance between parapsidal line (at the starting point) 0.90 (± 0.06 SD) mm. Pronotal angle obtuse. Mesoscutum length/width ratio 0.87 (± 0.05 SD); mesoscutum/mesoscutellum length ratio 3.01 (± 0.18 SD); mesoscutellum/ metanotum length ratio 1.59 (± 0.11 SD). Propodeum lateral carinae reaching dorsal margin; oblique carina very strong. (n=18)

Male. Length 5.64 (± 0. 47 SD) mm. Head length 1.60 (± 0.03 SD) mm. Head width 1.53 (± 0.01 SD) mm. Wing length 4.10 (± 0.18 SD) mm. (n=3)

Colouration. Head and mesosoma dark brown to black, no metallic sheen. Clypeus apex yellow. Labrum yellow. Mandible yellow with brown basomedially and light reddish-brown apex. Flagellum brown dorsally, testaceous ventrally. Pronotal lobe testaceous to yellow. Metasoma brown, apical margins reddish brown to narrowly testaceous. Legs black to brown with femur-tibia joints, base and apex of tibiae, and tarsi yellow. Tegula pale amber. Wing membrane hyaline, veins with subcosta brown, otherwise light brown to pale amber. Metasoma brown to black, apical margins reddish brown to narrowly testaceous.

Pubescence. Body hair colour white. Tomentum dense on face below eye emargination, near posterior margin of pronotal angle and lobe, space between pronotal lobe and tegula; sparse on gena, mesoscutum margins, preëpisternum, mesepisternum, T 2– T 3 basolaterally, and T 4 basally. Head and mesosoma with quite dense plumose and simple setae. Gena with quite dense plumose long setae. Metasomal sterna with short hairs, moderately plumose to simple, nearly bare in S1–S2. Wing hairs pale.

Surface sculpture. Clypeus shiny; punctures moderately dense (IS = 1–2 PD), diversopunctate. Supraclypeal area shiny, becoming imbricate medially; punctures dense to moderately dense (IS ≤ 2 PD). Paraocular area shiny reticulate; punctures crowded (IS = 0 PD). Frons punctulate-reticulate; punctures crowded (IS = 0 PD) or dense (IS <1 PD). Vertex reticulate-rugulose medially, becoming shiny to imbricate laterally; punctures dense (IS ≤ 1 PD) and obscure medially. Gena shiny and weakly rugulose-lineate posteriorly; punctures sparse (IS = 1–3 PD). Postgena sculpture imbricate-lineate, becoming shiny and weakly tessellate anteriorly. Tegula punctures absent. Mesoscutum imbricate, becoming shiny laterally; punctures dense (IS <1 PD), interspersed with scattered minute punctures in some areas, becoming slightly sparser submedially (IS = 1–1.5 PD). Mesoscutellum shiny; punctures dense marginally and on median line (IS <1 PD), moderately sparse submedially (IS = 1–2 PD), interspersed with scattered minute punctures in some areas. Metanotum shiny and becoming rugulose laterally, densely punctate medially (IS ≤ 1 PD). Metapostnotum rugae strong, anastomosing, reaching posterior margin and even go beyond posterior lateral margin; sculpture shiny to weakly imbricate. Preëpisternum sculpture rugose. Hypoepimeron rugulose; punctures crowded (IS = 0 PD), or obscure sometime. Mesepisternum reticulate-rugose to rugulose. Metepisternum rugulose. Propodeum lateral face imbricate to rugulose; posterior face rugose-imbricate, tessellate on propodeal triangle. T 1 anterior face shiny; dorsal surface shiny, becoming weakly coriarious on rim; punctures moderately sparse (IS = 1–3 PD), becoming sparse in small subapicolateral boss (IS = 2–4 PD) and absent on apical rim. T 2 disc weakly imbricate, becoming shiny apically; punctures small and moderately dense (IS = 1–2 PD) basally, becoming larger and denser (IS ≤ 1 PD), and again getting smaller and moderately dense (IS = 1–2 PD) near apical impressed area; rim coriarious; punctures minute, sparse (IS = 1–3 PD), absent apically.

Structure. Face length/width ratio 0.89 (± 0.03 SD). Clypeus projecting ~60% below suborbital tangent; clypeal area length/width ratio 1.15 (± 0.09 SD). Mandible short, reaching near opposing clypeal angle. Flagellomeres, except F1, elongate, F2 longer than F1 and pedicel combined. F1:pedicel length ratio 1.22 (± 0.09 SD); F2:F1 length ratio 0.28 (± 0.04 SD); F2 length/width ratio 1.95 (± 0.08 SD); F9 length/width ratio 1.73 (± 0.11 SD). Eyes strongly convergent below (UOD/LOD ratio 1.42 (± 0.01 SD). Gena clearly narrower than eye. Pronotal angle obtuse. Intertegular span 1.14 (± 0.04 SD) mm. Mesoscutum length/width ratio 0.92 (± 0.03 SD); mesoscutum/ mesoscutellum length ratio 2.40 (± 0.07 SD); mesoscutellum/metanotum length ratio 1.65 (± 0.08 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. (n=3)

Genitalia.As shown in Fig. 5 , gonostylus small, with short setae. Retrorse lobe long and broad, covered in short hairs, curved medially.

Range. Southern California through to Arizona, south to Baja California ( Figs. 6 , 7 ).

Floral hosts. ANACARDIACEAE : Rhus trilobata Nutt. • ASTERACEAE : Chaenactis glabriuscula DC. , Coreopsis sp. , Encelia farinosa Torr. & A.Gray , Lasthenia coronaria (Nutt.) , Ornduff, Lasthenia gracilis (DC.) Greene , Malacothrix californica DC. , Senecio californicus DC.,Thistle • BORAGINACEAE : Amsinckia tessellate A. Gray , Cryptantha intermedia (Gray) Greene , Phacelia distans Benth. , Phacelia minor (Harv.) Thell. , Plagiobothrys collinus (Phil.) I.M.Johnst. • BRASSICACEAE : Erysimum cheiranthoides L., Hirschfeldia incana (L.) Lagr.-Foss. • CACTACEAE : Cylindropuntia californica (Torr. & A.Gray) F.M.Knuth , Opuntia sp. • CARYOPHYLLACEAE : Minuartia douglasii (Torr. & A.Gray) Mattf. • ERICACEAE : Arctostaphylos sp. • FABACEAE : Prosopis sp. • LAMIACEAE : Salvia columbariae Benth. , Salvia mellifera Greene • LOASACEAE : Mentzelia micrantha (Hook. & Arn.) Torr. & A.Gray • ONAGRACEAE : Camissonia campestris subsp. campestris (Greene) P.H. Raven , Camissonia contorta (Dougl. ex Lehm.) Kearney , either Calylophus sp. or Camissonia sp. • PAPAVERACEAE : Eschscholzia californica Cham. , Platystemon californicus Benth., Poppy • PLANTAGINACEAE : Keckiella antirrhinoides (Benth.) Straw • POLEMONIACEAE : Eriastrum virgatum (Benth.) H.Mason , Gilia achilleifolia subsp. multicaulis (Benth.) V.E. Grant & A.D. Grant , Gilia latiflora subsp. davyi (Milliken) A.D. Grant & V.E. Grant • POLYGONACEAE : Eriogonum fasciculatum Benth. • RHAMNACEAE : Ceanothus crassifolius Torr. • ROSACEAE : Adenostoma fasciculatum Hook. & Arn. , Prunus subcordata Benth. • SALICACEAE : Salix laevigata Bebb, Sali x sp. • TAMARICACEAE : Tamarix gallica L.

Figures

FIGURE 3. Lasioglossum (Sphecodogastra) iridescens sp. nov., ♀, holotype. A. Dorsal habitus. B. Face. C. Lateral habitus. D. Metasoma. Scale bars = 1 mm.

FIGURE 4. Lasioglossum (Sphecodogastra) iridescens, ♂, paratype. A. Dorsal habitus. B. Face C. Lateral habitus. D. Metasoma. Scale bars = 1 mm.

FIGURE 5. Genitalia of Lasioglossum (Sphecodogastra) iridescens, ♂, paratype. A. Dorsal view. B. Posterior view. C. Lateral view.

FIGURE 6. Georeferenced collection records of Lasioglossum iridescens. (black squares) and predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence.

FIGURE 7. Distribution map of Lasioglossum iridescens (red dots), Lasioglossum dilisena (blue dots) and Lasioglossum silveirai (green dots).

FIGURE 8. Mesoscutum and mesoscutellum of female A. Lasioglossum iridescens, holotype. B. Lasioglossum dilisena, paratype. C. Lasioglossum silveirai, holotype. D. Lasioglossum silveirai, paratype with lacking metallic sheen.

FIGURE 9. Mesepisternum of female paratypes A. Lasioglossum iridescens. B. Lasioglossum dilisena. C. Lasioglossum silveirai.

FIGURE 10. Supraclypeal area of female A. L. iridescens, holotype. B. L. dilisena, paratype. C. L. silveirai, paratype.

FIGURE 11. Metatibial spur of female paratypes A&B. L. iridescens. C&D. L. dilisena E&F. L. silveirai. Scale bars = 0.25 mm.