Lasioglossum (Sphecodogastra) silveirai, 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 : 223-226

Lasioglossum (Sphecodogastra) silveirai sp. nov.

Figs. 7 , 8C, 8D , 9C , 10C , 11E, 11F , 14 , 15

Etymology. This species is named in honour of the late Fernando Silveira (Universidade Federal de Minas Gerais) for his contributions to bee taxonomy and his warm, jovial spirit, which made it a delight to attend international conferences on pollinators.

Holotype. USA — California • ♀; San Luis Obispo Co., La Panza Camp.; [35.3539° N, 120.2625° W]; elev. 660 m.; 25 April 1968; J. Powell leg.; UCRC GIBBS-11595 . [Verbatim label: La Panza Camp., S.L.O. Co., Calif IV-25-68 // J. Powell Collector // Lasioglossum GIBBS-11595 // Holotype/ Lasioglossum (Sphecodogastra) silveirai Hettiarachchi and Gibbs ]

Paratypes. USA — California • 1 ♀; Monterey Co., 3 air mi. NE of Paloma Creek ; [36.3036° N, 121.4118° W]; elev. 274 m .; 06 May 1975; J. Powell leg.; ex Ranunculus ; EMEC • 1 ♀; Monterey Co., Chew’s Ridge ; [36.3117° N, 121.5682° W]; elev. 1524 m.; 09 May 1975; J. Powell leg.; EMEC • 3 ♀♀; Monterey Co., Chew’s Ridge nr. White Oak camp; [36.3128° N, 121.5721° W]; elev. 1219.2m.; 08 May 1975; J. Powell leg.; ex Ranunculus ; EMEC • 1 ♀; ibid.; 08 May 1975; R. Wharton leg.; ex Ranunculus ; EMEC • 1 ♀; ibid.; 08 May 1975; R. Wharton leg.; EMEC • 2 ♀♀; Monterey Co., Chew’s Ridge, Santa Lucia Mts. ; [36.3117° N, 121.5682° W]; elev. 1524 m.; 08 May 1975; R. Wharton leg.; ex Pinus ; EMEC • 2 ♀♀; Monterey Co., Horse Bridge , 1.5 air mi SW of Arroyo Seco Grd. Sta.; [36.2219° N, 121.4950° W]; elev. 330 m .; 07 May 1975; R. Wharton leg.; EMEC • 1♀; San Benito Co., W side of Pinnacles National Monument ; [36.4886° N, 121.2217° W ]]; elev. 485 m; 02 Jul 1956; E.G. Linsley leg.; ex Hemizonia lobbii ; EMEC • 1 ♀; San Benito Co., 5 mi. SW of Paicines, Limeklin Rd. ; [36.6362° N, 121.4186° W]; 24 Mar 1966; R. L. Langston leg.; UCRC • 10 ♀♀; San Benito Co., SW. of Paicines ; [36.7286° N, 121.2775° W]; 24 Apr 1968; J. Powell leg.; UCRC • 1 ♀; San Luis Obispo Co., La Panza Camp.; [35.3539° N, 120.2625° W]; elev. 660 m .; 25 Apr 1968; P.A. Opler leg.; ex Rhamnus crocea ; UCRC • 1 ♀; ibid.; 25 Apr 1968; J. Powell leg.; UCRC • 3 ♀♀; ibid.; 25 Apr 1968; J. Doyen leg.; ex Rhamnus crocea ; UCRC • 2 ♀♀; Ventura Co., Lockwood Valley ; [34.7331° N, 119.0958° W]; elev. 1555 m.; 05 May 1959; P.H. Timberlake leg.; ex Phacelia ciliata ; UCRC • 2 ♀♀; Ventura Co., Lockwood Valley, nr. Stauffer P.O.; [34.7556° N, 119.0592° W]; elev. 1540 m.; 05 May 1959; P.D. Hurd leg.; ex Euphorbia albomarginata ; EMEC .

Description

Female. Length 5.57 (± 0.34 SD) mm (n=7). Head length 1.51 (± 0.07 SD) mm (n=16). Head width 1.67 (± 0.08 SD) mm (n=16). Wing length 4.11 (± 0.27 SD) mm (n=6).

Colouration. Head and mesosoma dark brown to black, mesoscutum and mesoscutellum with or without an oily metallic sheen. If they have a metallic sheen, it can be metallic green either with or without a purple tint. Metallic sheen not as prominent compared to the other two species, with nearly 30% of specimens (n=30) lacking the sheen or having a sheen that is not notable (Fig. D). Clypeus apex dark brown. Labrum dark brown. Mandible brown basally, light brown apically with reddish brown apex. Flagellum light brown dorsally, brown ventrally. Pronotal lobe brown to dark brown. Tegula brown. Wing membrane hyaline, faintly dusky, veins with subcosta brown, otherwise honey-coloured. Legs dark 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, T2–T3 basolaterally; moderately dense on metanotum anterior margin; scattered on T4–T5; 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. T1 with sparse erect setae.

Surface sculpture. Clypeus shiny, becoming weakly imbricate basolaterally; punctures large, irregularly spaced (IS ≤ PD) on apical third, smaller and denser on near basal margin (IS ≤1 PD). Supraclypeal area mostly shiny; punctures sparse medially (IS = 2–4 PD). Paraocular area imbricate to reticulate, becoming shiny laterally; punctures mostly 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 = 1–3 PD). Postgena shiny, becoming weakly tessellate posteriorly. Tegula mostly shiny and impunctate except the base. Tegula base imbricate with punctures absent or obscure. Mesoscutum shiny, becoming tessellate to imbricate anteromedially; punctures large and small intermixed, mostly dense on marginally and on median line (IS <1 PD), sparser submedially, becoming shallow and indistinct anteromedially. Punctures mesad of parapsidal line (IS = 2–4 PD) slightly sparser than laterad of parapsidal line (IS = 2–3 PD) and becoming closer near medial line (IS ≤ 1 PD). Mesoscutellum shiny; punctures comparatively smaller than the other two species, dense marginally and on median line (IS ≤ 1 PD), sparser submedially (IS = 1–5 PD), diversopunctate, Metanotum shiny and becoming weakly rugulose laterally, densely punctate medially (IS ≤ 1 PD). Metapostnotum rugae strong, anastomosing, reaching posterior margin; sculpture shiny to imbricate. Preëpisternum rugose. Hypoepimeron shiny, becoming weakly rugulose posteriorly; punctures moderately dense (IS = 1–2 PD), and sometime there are few scattered minute punctures anteriorly. Mesepisternum rugose dorsally and becoming strongly so ventrally; punctures obscure or indistinct dorsally, absent ventrally. Metepisternum ruguloso-lineate dorsally, imbricate ventrally. Propodeum lateral face imbricate anteriorly and dorsally, otherwise tessellate; posterior face tessellate. T1 anterior face shiny, punctures small and very sparse; T1 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. T2 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 0.78 (± 0.01 SD). Eyes convergent below [UOD/LOD ratio 1.06 (± 0.03 SD)]. Clypeus projecting ~60% below suborbital tangent; clypeal area length/width ratio 0.86 (± 0.07 SD). Gena narrower than eye. Protibial spur with apical serrations quite longer than length to width of malus. Inner metatibial spur pectinate, basal branches shorter or subequal to width of rachis ( Figs. 11E, 11F ). Intertegular span 1.11 (± 0.10 SD) mm. Distance between parapsidal line 0.85 (± 0.08 SD) mm. Pronotal angle obtuse. Mesoscutum length/width ratio 0.87 (± 0.04 SD); mesoscutum/mesoscutellum length ratio 2.83 (± 0.21 SD); mesoscutellum/metanotum length ratio 1.59 (± 0.11 SD). Propodeum lateral carinae reaching dorsal margin; oblique carina very strong. (n=18)

Male. Unknown.

Range. Coastal Mountains of central California ( Figs. 7 , 15 ).

Floral hosts. ASTERACEAE : Hemizonia lobbii Greene • BORAGINACEAE : Phacelia ciliata Benth. • EUPHORBIACEAE : Euphorbia albomarginata Torr. & A.Gray • RANUNCULACEAE : Ranunculus sp. • PINACEAE : Pinus sp. • RHAMNACEAE : Rhamnus crocea Nutt.

Figures

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.

FIGURE 14. Lasioglossum (Sphecodogastra) silveirai sp. nov., ♀, holotype. A. Dorsal habitus. B. Face. C. Lateral habitus. D. Metasoma. Scale bars = 1 mm.

FIGURE 15. Georeferenced collection records of Lasioglossum silveirai (black squares) and predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence.