Lasioglossum

Walker, Kenneth L., 2025, The “ weak-veined ” Lasioglossum in Australia, New Zealand and West New Guinea, with descriptions of three new subgenera (Hymenoptera: Apoidea: Halictidae), Zootaxa 5651 (1), pp. 1-94 : 63-65

Lasioglossum . ( Enigmalictus ). excelsum . new species urn:lsid:zoobank.org:act:E55E952F-CADF-43AE-818B-6FEE812C87B6

( Figures 16, 26C–D, 31B, 45A–B, 46A–B, 47A–B)

Diagnosis. Females of L. excelsum can be recognised by the combination of: Body length 6.12 (± 0.54 SD) mm ( Fig. 45A). ITS = 1.20 (± 0.06 SD) mm. Face short (FL/HW ratio 0.77 (± 0.04 SD)). Head and mesosoma black, metasoma either entirely light red brown or T1–T4 light brown, T5–T6 dark brown ( Fig. 45A). Mesoscutum medially with equally sized punctures, medially with sparse punctures (IS = 2–6 PD), inner margins of parapsidal lines with moderately dense punctures (IS = 1–2 PD), in parapsidal areas with moderate punctures (IS = 2–3 PD), in posterolateral corners with moderate punctures (IS = 1–3 PD) and along posterior margin with moderately sparse punctures (IS = 2–4 PD) ( Fig. 26D). Metapostnotum striate ( Fig. 46A). Inner metatibial spur pectinate and oblique with six, small, sharply pointed teeth less than one third width of rachis.

Males of L. excelsum can be recognised by the combination of: Body length 7.23 (± 0.12 SD) mm ( Fig. 45B). ITS = 1.23 (± 0.04 SD) mm. Face round (FL/HW ratio 0.87 (± 0.04 SD)). Mesoscutum with dense punctures (IS ≤ 1 PD) medially and laterally ( Fig. 46B). Metasoma sterna S3 with weak lateral, plumose hair tufts, S4 with dense lateral, plumose tufts (Length of hair:MOW ratio as ratio 2.83 (± 0.04 SD)), S5 with lightly less dense lateral, plumose hair (Length of hair:MOW ratio as 2.01 (± 0.0 3 SD)). S5 apical margin weakly curved basally ( Fig. 31B). Genitalia with gonostylus:gonocoxite length ratio 1.11 (± 0.02 SD), retrorse lobe present ( Figs. 47A–B).

Comments. See diagnosis for L. disclusum to distinguish between L. disclusum , L. exoneuroides and L. excelsum . This is another species with a preference for high altitudes e.g. Mt Hotham (1,861 m) and Falls Creek (1,842 m). Most of the specimens were collected at high altitude locations; however, there are also records from lower altitudes such as Toolangi, Victoria at 600 m.

Etymology. The species named “excelsum ” is from the Latin word “excelsus” which means “high” and refers to the high-altitude locations generally preferred by this species. An appropriate translation would be “high altitude species”.

Holotype of “ Lasioglossum excelsum ”. AUSTRALIA. Victoria. ♀: Mt Hotham—Dargo High Plains , [37.0666S 147.1500E], 8 – 9 April 2000, K. Walker, on Hypochaeris radicata (HYM-99616. NMV).

Paratypes of “ Lasioglossum excelsum ”. (29 specimens, 16 ♀, 13 ♂) AUSTRALIA. Victoria. (13 ♀, 4 ♂) Mt Hotham–Dargo High Plains, [37.0666S 147.1500E], 8 – 9 April 2000, K. Walker, on Hypochaeris radicata (HYM-99617–99633. NMV); (4 ♂) Falls Creek, [36.8666S 147.2833E], 5 March 1992, K. Walker, on Leptospermum (HYM-99634–99637. NMV); (3 ♂) Dinner Plain, [36.9833S 147.2833E], 4 March 1992, K. Walker, on Senecio (HYM-99638–99640. NMV); (2 ♂) Dinner Plain, 1572m, [37.02345S 147.2833E], 18 March 2021, K. Walker, Achillea & Hypochaeris (HYM-93699–93700. NMV); (1 ♀) 10 km S Dinner Plain, 1570m, [37.05395S 147.2591E], 11 Feb 2021, K. Walker, on Helichrysum (HYM-93697. NMV); (1 ♀) Falls Creek, 1551m, [36.8636S 147.2848E], 17 March 2021, K. Walker, on Senecio (HYM-93706. NMV); (1 ♀) Falls Creek, 1459m, [36.8557S 147.2737E], 17 March 2021, K. Walker, on Hypochaeris radicata (HYM-93703. NMV).

Additional non-type specimens examined. (57– 27 ♀, 32 ♂): AUSTRALIA. New South Wales and Canberra: (1 ♀) Bulls Head , 10 Oct 2001, M. Batley, on Acacia melanoxylon (AM) ; (1 ♀) Yarrangobilly , 14 Feb 1981, G.A. Holloway & D.J. Hyatt ( AM); (2 ♀) Brindabellas , 22 Oct 1972, O.W. Richards ( ANIC); (4 ♀) Mt Gingera , 10 Nov 1976, J.C. Cardale ( ANIC); (2 ♀) Mt Gingera , 24 Feb 1959, E.F. Riek ( ANIC) .

Victoria: (11 ♀) Toolangi, 18 Nov 2000, K. Walker, on Ranunculus lappaceus (NMV) ; (1 ♀) Mt Buffalo Nat Pk , 29 Jan 1969, D. Crosby ( NMV) .

Tasmania: (4 ♂) Gordon River Rd , 20 km W Maydena, 9 Feb 1988, K. Walker, on Leptospermum (NMV) ; (17 ♂) Needles Picnic area, 9 Feb 1988, K. Walker, on Leptospermum (NMV) ; (6 ♂) Pelion Hut, 3 km S Mt Oakleigh, 5–10 Feb 1990, I.D. Nauman, open forest, on Wahlenbergia (ANIC) ; (3 ♀) 12 km NNE Bronte Park, 2 Feb 1983, I.D. Naumann & J.C. Cardale, on Lomatia (ANIC) ; (2 ♂) 14 km SWS Wilmot, 31 Jan 1983, I.D. Naumann & J.C. Cardale ( ANIC); (1 ♂) Lake Fenton , Mt Field Nat Pk, 31 Jan 2001, K. Hingston, on Pultenaea juniperina (NMV) ; (1 ♂) Breona, 27 Jan 1960; F.J. D. McDonald ( QM); (1 ♂) Cradle Mt , 2 Jan 1934, A.J. Turner ( QM) .

Description

Female. Body length 6.12 (± 0.54 SD) mm. ITS = 1.20 (± 0.06 SD) mm. Head length 1.57 (± 0.07 SD) mm. Head width 1.74 (± 0.16 SD) mm. Wing length 4.93 (± 0.65 SD) mm. (n=10).

Colouration. Head and mesosoma black. Clypeus black. Labrum light red brown. Mandible red brown basally and medially with dark reddish-brown apically. Flagellum dark brown to black dorsally and ventrally. Pronotal lobe dark brown. Tegula dark reddish-brown. Wing membrane hyaline, faintly dusky, veins with subcosta brown, otherwise honey coloured. Legs with coxa, trochanter and femur dark brown, fore and mid legs with both tibiae and all tarsi light red brown, hind leg with tibia and metatarsi red brown to brown. Metasoma either entirely light red brown or T1–T4 light brown, T5–T6 dark brown. Body setae white. Wing hairs pale. ( Figs. 26C–D, 45A, 46A).

Pubescence. Head with frons, vertex and gena with sparse cover of erect hair, paraocular area with a light cover of appressed hair ( Fig. 26C). Pronotal lobe with a cover of short, erect, plumose hair, posterior margin of spiracle cover with dense layer of short, appressed hair. Mesoscutum with sparse cover of short, erect hair, a few more hairs along posterior margin ( Fig. 26D). Mesepisternum with weak cover of erect, plumose hair. Lateral surface of propodeum with moderate cover of elongated, branched, erect hair and short appressed hair, posterior surface with spare cover of erect hair. Metafemoral scopa with dense plumose hairs. T1–T3 dorsally almost bare, some hairs laterally, T4–T6 with sparse cover of short setae.

Surface sculpture. Clypeus shining and smooth on anterior half, dull with imbricate pattern on basal half, apical half punctures large, deeply impressed, irregularly with moderately sparse punctures (IS = 2–3 PD), basal half with smaller moderately sparse punctures (IS = 2–3 PD). Supraclypeal area dull, with imbricate pattern and moderately sparse punctures (IS = 2–3 PD). Paraocular area smooth and impunctate. Frons dull, with minute, crowded punctures (IS = 0 PD) with rim of each puncture raised and forms part of adjoining puncture. Vertex impunctate with imbricate pattern. Gena strigulate with parallel lines. Tegula shining, impunctate on apical half, basal half substrigulate with minute, dense punctures (IS = 0–1 PD). Mesoscutum dull, entirely covered with a thick imbricate pattern, equally puncture sized, medially with moderately sparse punctures (IS = 2–6 PD), inner margins of parapsidal lines with moderately dense punctures (IS = 1–2 PD), in parapsidal areas with moderately sparse punctures (IS = 2–3 PD), in posterolateral corners with moderate punctures (IS = 1–3 PD) and along posterior margin with sparse punctures (IS = 2–4 PD) ( Fig. 26D). Mesoscutellum dull, imbricate, with dense punctures (IS = 1 PD), laterally with moderate punctures (IS = 1–2 PD). Metanotum dull, impunctate, imbricate. Metapostnotum striate across entire surface, medially striae extend beyond midpoint to posterior margin but not reaching rim, striae laterally reaching dorsolateral slope, surface with an imbricate sculpture pattern ( Fig. 46A). Propodeum lateral face dull, imbricate and impunctate, posterior face dull, imbricate and impunctate, lateral and oblique carinae absent ( Fig. 46A). Preëpisternum weakly scabrous. Mesepisternum coarsely imbricate and impunctate. Metepisternum dull, imbricate and impunctate. Hypoepimeron inflated, dull, almost glabrous, weakly imbricate and impunctate. T1 dorsal surface shining, with minute, sparse punctures (IS = 4–6 PD). T2 shining with similar punctures to T1.

Structure. Face short (FL/HW ratio 0.77 (± 0.04 SD)). Eyes convergent below [UOD/LOD ratio 1.07 (± 0.03 SD)]. Median ocellus width/ocellocular distance ratio [MOW:OOD ratio 0.51 (± 0.4 SD)]. Clypeus extends ~50% below suborbital tangent, clypeus length/width ratio 0.45 (± 0.06 SD). Clypeus slightly produced medially with apicolateral denticles. Gena narrower than eye. Mandible long, reaching opposing clypeal angle. Protibial spur with apical serrations longer than length to width of malus. Inner metatibial spur pectinate and oblique with six, small, sharply pointed teeth less than one third width of rachis. Distance between parapsidal line (at the starting point) 0.91 (± 0.04 SD) mm. Pronotal angle rounded and weakly projected. Mesoscutum length/width (widest point) ratio 0.78 (± 0.04 SD). Mesoscutum/mesoscutellum length ratio 2.93 (± 0.13 SD). Mesoscutellum/metanotum length ratio 1.66 (± 0.14 SD). Stigma medium, 0.84 mm long, 0.24 mm wide (ratio ~3.50 (± 0.06 SD)), margin in marginal cell convex, marginal cell 1.32 mm long, 0.36 mm wide, free portion about 1.6X that subtended by submarginal cells (0.77 mm: 0.46 mm). 1m-cu distinctly inside the second submarginal cell and separated from 1rs-m. Stigma perpendicular goes about middle of third submarginal cell.

Male. Body length 7.23 (± 0.12 SD) mm. ITS = 1.23 (± 0.04 SD) mm. Head length 1.87 (± 0.05 SD) mm. Head width 1.82 (± 0.03 SD) mm. Wing length 5.34 (± 0.10 SD) mm. (n=5).

Colouration. Head and mesosoma black. Clypeus apical half yellow-white, basal half black. Labrum dark brown to black. Mandible with dark brown basal patch, followed by dull yellow patch followed by red brown and tip dark reddish colour. Flagellum dark brown to black dorsally and ventrally. Pronotal lobe dark brown. Metasoma T1–T3 black basally and brown apically, T4–T6 black. Legs dark brown except fore and mid tarsi lighter brown. Tegula dark red brown. Wing membrane hyaline, veins with subcosta brown, otherwise light brown to pale amber. Wing hairs pale. ( Figs. 45B, 46B).

Pubescence. Body hair colour brownish white. Frons with sparse cover of erect setae, dense setae between antennal bases, moderate cover of appressed hair in paraocular area. Clypeus dorsal surface almost glabrous, with sparse erect hairs, laterally with denser long setae ( Fig. 46B). Gena with sparse cover of erect setae. Pronotal lobe almost glabrous, some denser hair around posterior margin of spiracle cover. Sparse cover of hair on preëpisternum and mesepisternum. Metanotum, mesoscutum with sparse cover of short, erect hairs. T1–T6 with sparse cover of short, erect hair, a few long hairs on margins of tergites. Metasoma sterna S3 with weak lateral, plumose hair tufts, S4 with dense lateral, plumose tufts (Length of hair:MOW ratio as 2.83 (± 0.04 SD)), S5 with lightly less dense lateral, plumose hair (Length of hair ratio:MOW ratio as 2.01 (± 0.03 SD)). S6 with short, simple hair pointing towards midline ( Fig. 31B).

Surface sculpture. Clypeus with a dull sheen, apical half with moderately dense, large punctures (IS = 1–2 PD), basal half with moderately dense punctures (IS = 1–3 PD) with imbricate sculpture, diversopunctate between apical and basal halves. Supraclypeal area with imbricate sculpture, with minute, moderately dense punctures (IS = 1–2 PD). Paraocular area smooth and shining, impunctate. Frons with minute, crowded punctures (IS = 0 PD). Vertex weakly rugulose across vertex surface. Gena weakly rugulose. Tegula shining, impunctate across apical half, with dense (IS ≤ 1 PD) to moderate punctures (IS = 1–2 PD) basally. Mesoscutum dull, with dense punctures (IS ≤ 1 PD) medially and laterally. Mesoscutellum dull, with crowded punctures medially, dense punctures laterally (IS ≤ 1 PD). Metanotum dull, scabriculous. Metapostnotum rugulose with striae reaching about halfway to posterior margin, sculpture shining. Preëpisternum and mesepisternum imbricate and with sparse punctures (IS = 2–3 PD). Metepisternum dull and striate. Propodeum lateral face scabriculous, posterior face imbricate-scabriculous. T1 dorsal surface shining, with dense punctures medially (IS ≤ 1 PD) and moderately sparse and minute punctures laterally (IS = 1–3 PD). T2 shining, with moderately sparse punctures (IS = 2–4 PD).

Structure. Face round (FL/HW ratio 0.87 (± 0.04 SD)). Clypeus projecting ~50% below suborbital tangent, clypeus length/width ratio 0.76 (± 0.05 SD). Mandible short, not reaching near opposing clypeal angle. Flagellomeres, except F1, elongate, F2 equal to F1 and pedicel combined. F2:F1+pedicel length ratio 1.00 (± 0.02 SD). F2:F1 length ratio 1.71 (± 0.03 SD); F2 length/width ratio 1.71 (± 0.03 SD). F9 length/width ratio 1.50 (± 0.08 SD). Eyes strongly convergent below (UOD/LOD ratio 1.54 (± 0.03 SD). Gena narrower than eye. Mandible long, reaching opposing clypeal angle. Pronotal angle rounded and not well projected. Mesoscutum length/width ratio 0.83 (± 0.03 SD). Mesoscutum/mesoscutellum length ratio 2.63 (± 0.03 SD). Mesoscutellum/metanotum length ratio 1.90 (± 0.04 SD). Propodeum lateral and oblique carinae absent. S5 apical margin weakly curved basally.

Genitalia. Gonobase flat at bottom, tapered basally, arms ventroapically complete, gonobase:gonocoxite length ratio 0.94 (± 0.03 SD), gonostylus:gonocoxite length ratio 1.11 (± 0.02 SD), gonostylus apically with elongated setae, inner margin setae curved at tip and setae from each gonostylus extends beyond midway between gonostyli, penis valve inner margin with setae, retrorse lobe present, long and narrow (length 3 times width), not reaching gonobase, densely setose medially with short setae, apical and on inner margin with elongated setae, length of setae equal to or greater than width of retrorse lobe, setae radiating out from margins of retrorse lobe, setae straight at tip. ( Figs. 47A–B).

Range. Occurs in New South Wales, Victoria and Tasmania ( Fig. 16).

Flight period. This species has been collected between February and March and again between September to November ( Table 1).

Floral hosts. ASTERACEAE : Hypochaeris radicata . CAMPANULACEAE : Wahlenbergia sp. FABACEAE : Acacia melanoxylon ; Pultenaea juniperina . PROTACEAE: Lomatia sp. RANUNCULALES : Ranunculus lappaceus .