Lasioglossum (Sphecodogastra) dilisena, 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 : 218-223

Lasioglossum (Sphecodogastra) dilisena sp. nov.

Figs. 7 , 8B , 9B , 10B , 11C, 11D , 12 , 13

Etymology. The specific epithet ‘dilisena’ is derived from the Sinhala word ‘dilisena’, which means ‘shining’, but is used here as a noun in apposition. This name was chosen because all three species described in this paper have an unusual metallic reflection on the mesosoma that is not seen in other known North American species in the subgenus Sphecodogastra . The first author is also a native speaker of Sinhala from Sri Lanka. Sinhala language is one of the official and national languages of Sri Lanka and the mother tongue of the majority people of Sri Lanka. Through this naming choice, we hope to honour all the linguistic and cultural diversity of the world.

Holotype. USA — California • ♀; Santa Clara Co., 8 mi. E of Mount Hamilton [37.3416° N, 121.4964° W]; 16 April 1955; D.J. Burdick leg.; UCRC GIBBS- 11531. [Verbatim label: Calif: Sta. Clara Co., Mt. Hamilton, 8mi. E. VI-16-55 / D.J. Burdick Collector // Lasioglossum GIBBS- 11531 // Holotype / Lasioglossum (Sphecodogastra) dilisena Hettiarachchi and Gibbs ]

Paratypes. USA — California • 1 ♀; Alameda Co., Arroyo Mocho; 37.5839° N, 121.6297° W; 09 Apr 1957; D.J. Burdick leg.; EMEC • 3 ♀♀; Santa Clara Co., 5 mi. E of Mount Hamilton; [37.3414° N, 121.5505° W]; 16 Apr 1955; D.J. Burdick leg.; UCRC • 1 ♀; Santa Clara Co., 8 mi. E of Mount Hamilton; [37.3416° N, 121.4964° W]; 16 Apr 1955; D.J. Burdick leg.; EMEC • 21 ♀♀; Santa Clara Co., 8 mi. E of Mount Hamilton; [37.3416° N, 121.4964° W]; 16 Apr 1955; D.J. Burdick leg.; UCRC • 1 ♀; Santa Clara Co., 11 mi. E of Mount Hamilton; [37.3386° N, 121.4419° W]; 19 Apr 1956; D.J. Burdick leg.; UCRC • 1 ♀; Sierra Co., 5 mi. NNE Sierra City; [39.6332° N, 120.5981° W]; 07 Sep 1964; J. Bedea leg.; OSAC • 6 ♀♀; Mariposa Co., 5.5 mi. N of Coulterville; [37.7892° N, 120.1902° W]; 18 July 1963; R.W. Thorp leg.; ex Clarkia dudleyana ; EMEC • 1 ♀; Tulare Co., 4 mi. N of Kaweah; [36.5278° N, 118.9182° W]; 13 May 1963; C. A. Toschi leg.; UCRC • 1 ♀; Tulare Co., Three Rivers; [36.4386° N, 118.9044° W]; elev. 265 m.; 10 June 1925; P.H. Timberlake leg.; ex Penstemon sp. ; UCRC • 2 ♀♀; Tulare Co., Coffee Camp; [36.1519° N, 118.7425° W]; elev. 620 m.; 17 June 1953; P.H. Timberlake leg.; ex Clarkia purpurea subsp. viminea (verbatim: Godetia viminea ); UCRC • 3 ♀♀; Kern Co., Miracle Hot Springs; [35.5756° N, 118.5344° W]; elev. 725 m.; 29 April 1964; J. Powell leg; UCRC.

Description

Female. Length 5.66 (± 0.42 SD) mm (n=6). Head length 1.57 (± 0.04 SD) mm (n=16). Head width 1.65 (± 0.06 SD) mm (n=6). Wing length 4.20 (± 0.19 SD) mm (n=16).

Colouration. Head and mesosoma dark brown to black, mesoscutum and mesoscutellum with an oily metallic sheen with variable reflections; most specimens with a green reflection, while some display a green-purple mixture and others with a greater prominence of purple reflection around the parapsidal line and its vicinity. Clypeus apex dark brown. Labrum dark 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 dark brown, 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; 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 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 imbricate basolaterally, mostly becoming weakly or moderately imbricate medially; punctures dense laterally (IS ≤ 1 PD) and moderately dense to moderately sparse (IS = 1–2 PD) medially. Paraocular area imbricate to 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 = 1–3 PD). Postgena shiny, becoming 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 = 1–3 PD) slightly sparser than laterad of parapsidal line (IS = 1–2 PD), becoming closer submedially and adjacent to 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, densely punctate medially (IS ≤ 1 PD). Metapostnotum rugae strong, anastomosing, reaching at the middle of posterior margin; sculpture shiny to imbricate. Preëpisternum rugose. Hypoepimeron weakly rugulose; punctures dense (IS <1 PD), or sometime obscure, and sometime there are few scattered minute punctures anteriorly. Mesepisternum rugose mostly throughout; punctures obscure dorsally, absent ventrally. 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. T 2 disc imbricate to coriarious; punctures moderately dense basally (IS = 1–2 PD), becoming abruptly 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 0.81 (± 0.02 SD). Eyes convergent below [UOD/LOD ratio 1.03 (± 0.03 SD)]. Clypeus projecting ~66% below suborbital tangent; clypeal area length/width ratio 0.83 (± 0.05 SD). Gena narrower than eye. Protibial spur with apical serrations as long as width of malus. Inner metatibial spur pectinate, branches mostly shorter than width of rachis ( Figs. 11C, 11D ). Intertegular span 1.14 (± 0.08 SD) mm. Distance between parapsidal line (at the starting point) 0.87 (± 0.08 SD) mm. Pronotal angle obtuse. Mesoscutum length/width ratio 0.88 (± 0.03 SD); mesoscutum/mesoscutellum length ratio 2.84 (± 0.16 SD); mesoscutellum/metanotum length ratio 1.54 (± 0.19 SD). Propodeum lateral carinae reaching dorsal margin; oblique carina very strong. (n=18)

Male. Unknown

Range. Diablo and Sierra Nevada mountain ranges of California ( Figs. 7 , 13 ).

Floral hosts. ONAGRACEAE : Clarkia dudleyana (Abrams) J.F.Macbr. , Clarkia purpurea subsp. viminea (Douglas ex Hook.) H. Lewis & M. Lewis • PLANTAGINACEAE : Penstemon sp.

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

FIGURE 13. Georeferenced collection records of Lasioglossum dilisena (black squares) and predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence.