Lasioglossum rufibasis Walker, 2025

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 : 74-77

Lasioglossum . ( Enigmalictus ). rufibasis ( Cockerell 1923) new status

( Figures 2, 16, 17C, 27A–B, 51)

Halictus rufibasis Cockerell 1923, p. 238 (original description); Cockerell 1933, p. 296 (key); Cockerell 1933, p. 319 (redescription).

Lasioglossum (Chilalictus) rufibase — Michener 1965, p. 175 (generic and subgeneric status change).

Diagnosis. Females of L. rufibasis can be recognised by the combination of: Body length 5.49 (± 0.40 SD) mm ( Fig. 51). ITS = 1.10 (± 0.03 SD) mm. Face short (FL/HW ratio 0.79 (± 0.05 SD)). Head and mesosoma black. Metasoma T1–T2 light brown, T3–T6 dark brown ( Fig. 51). Mesoscutum medially diversopunctate, with sparse punctures (IS = 2–10 PD), inner margins of parapsidal lines with sparse punctures (IS = 3–6 PD), and in parapsidal areas almost impunctate with only a few isolated punctures, in posterolateral corners with moderately sparse punctures (IS = 2–4 PD) and along posterior margin with moderately sparse punctures (IS = 2–3 PD) ( Fig. 27A). Metapostnotum striate across entire surface ( Fig. 27B). Inner metatibial spur coarsely pectinate with 3 oblique, well separated, pointed teeth, tooth length up to 5 times width of rachis ( Fig. 17C).

Comments. There is considerable body colour variation in this species. The type has the head and mesosoma black while other specimens exhibit body colour variation from brown to light brown (e.g. Mt Glorius ( BPBM) and Mt Tambourine ( SEMK) specimens). These brown coloured specimens are conspecific due to similar mesoscutum sparse punctation (medially and in parapsidal areas (IS = 3–4 PD)) and inner metatibial spur with 3 large, separated, pectinate, apically acute teeth. Whether specimens with the light brown colours were callow when collected may be the reason .

The species name “rufibasis ” is a Latinized noun so the species name should remain as “rufibasis ” in combination with Lasioglossum rather than as Michener 1965 changed the name to “rufibase ”.

Etymology. The species name “rufibasis ” comes from two words: “rufus” is Latin for “reddish” and “basis” is a Greek word meaning “foundation”. An appropriate translation would be the combination of these words refers to Cockerell (1923, p. 238) description noting the first segment of the “abdomen is ferruginous”.

Syntype of “ Halictus rufibasis ”. AUSTRALIA. Queensland. ♀: National Park (Probably Binna Burra, Lamington National Park ), Dec 1919, H. Hacker ( QM Hy /2741. Type in poor condition: Head dislodged and glued to pith, missing right fore and left hind legs, mid right tarsi and metasoma. QM) .

Additional material examined. (40 ♀ specimens): AUSTRALIA. Queensland. (4 ♀) National Pk , Dec 1921, H. Hacker. (1♀ SEMK; 3♀ QM); (2 ♀) Cunningham’s Gap, 16 March 1959, C.D. Michener ( SEMK); (1 ♀) Cunningham’s Gap, 25 February 1959, C.D. Michener, on flowers of Solanum (SEMK) ; (5 ♀) Mt Tamborine, 20 Feb 1959, C.D. Michener, on flowers of Erigeron floribundus (SEMK) ; (1 ♀) Mt Glorious , 13 Nov 1961, L & M Gressitt ( BPBM); (8 ♀) Mt Glorious SF, subtropical rainforest, (4 ♀) 25–30 Oct 1978, (2 ♀) 9–16 April 1987, (1 ♀) 10–17 Dec 1987, (1 ♀) 11–18 Feb 1988, Y. Basset, on Argyrodendron actinophyllum (QM) ; (2 ♀) Brisbane Forest Pk, 29 Dec 2007, L.J. Cookson, malaise trap ( NMV) .

New South Wales. (4 ♀) 3 km N of Lansdowne , 4 Jan 1999, 9 Dec 1999, 3 Deb 2000, G. Williams, ex. wet sclerophyll forest, on Pollia crispata (NMV) ; (1 ♀) Lorien Wildlife Refuge, 3 km N of Lansdowne , 4 Jan 1999, 9 Dec 1999, 3 Deb 2000, G. Williams, ex. wet sclerophyll forest, on Lobelia trigonocaulis (NMV) ; (1 ♀) Nth Brother Mtn, Laurieton , 11–23 Feb 1999, G. Williams, ex. malaise trap in rainforest ( NMV); (1 ♀) Narooma, 17 Dec 1946 ( AM); Sydney, Royal National Park , 10 Oct 1991, P. Bernhardt, on Hibbertia scandens (NMV) .

Redescription of female and male

Female. Body length 5.49 (± 0.40 SD) mm. ITS = 1.10 (± 0.03 SD) mm. Head length 1.39 (± 0.04 SD) mm. Head width 1.57 (± 0.17 SD) mm. Wing length 4.46 (± 0.48 SD) mm. (n=10).

Colouration. Head and mesosoma black (type black but in some specimens colour varies from integument entirely light brown to dark brown). Clypeus apical margin brown, remainder black or entirely light brown if head brown. Labrum brown. Mandible dark red brown basally, red brown medially with reddish-brown apically. Flagellum dorsally and brown ventrally. Pronotal lobe brown. Tegula brown. Mesoscutellum dark brown (light brown in two specimens). Wing membrane hyaline, faintly dusky, veins with subcosta brown, otherwise honey coloured. Legs light red-yellow brown colour. Metasoma T1–T2 light brown, T3–T6 dark brown. Body setae white. Wing hairs pale. ( Figs. 2, 17C, 27A–B, 51).

Pubescence. Head with frons, paraocular area, clypeus, vertex and gena with sparse cover of erect hair ( Fig. 2). Pronotal lobe almost bare, posterior margin of spiracle cover with dense layer of short, appressed hair. Mesoscutum and mesoscutellum with sparse cover of short, erect hair, a few more hairs along posterior margin ( Fig. 27A). Mesepisternum with weak cover of erect hair. Lateral surface of propodeum with moderate cover of elongated, branched, erect hair, posterior surface with spare cover of erect hair ( Fig. 27B). Metafemoral scopa with dense plumose hairs ( Fig. 51). T1–T4 dorsally almost bare, some hairs laterally, T5–T6 with sparse cover of short setae ( Fig. 5).

Surface sculpture. Clypeus shining and smooth on anterior half, dull with imbricate pattern on basal half, apical half with large, deeply impressed, irregularly spaced moderately dense punctures (IS = 1–2 PD), basal half with smaller, rounded moderately sparse punctures (IS = 2–3 PD). Supraclypeal area dull, with imbricate pattern, medially and laterally with moderately sparse punctures (IS = 2–3 PD. Paraocular area smooth and impunctate. Frons dull, imbricate, medially with moderately sparse punctures (IS = 2–4 PD) ( Fig. 2). 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 with a dull sheen, entirely covered with imbricate pattern, medially diversopunctate with sparse punctures (IS = 2–10 PD), inner margins of parapsidal lines with sparse punctures (IS = 3–6 PD) in parapsidal areas almost impunctate with only a few isolated punctures, in posterolateral corners with moderately sparse punctures (IS = 2–4 PD) and along posterior margin with moderate punctures (IS = 2–3 PD) ( Fig. 27A). Mesoscutellum dull, imbricate with dense punctures (IS = 1 PD) medially and laterally with shallow, moderate punctures (IS = 1–2 PD). Metanotum dull, impunctate, imbricate. Metapostnotum striate across entire surface, medially striae reaching halfway to posterior margin, laterally striae extend onto dorsolateral slope, posterior margin rounded, sculpture shining but imbricate ( Fig. 27B). Propodeum lateral face dull, imbricate and impunctate, posterior face shining, imbricate and impunctate, lateral carina present, oblique carina absent ( Fig. 27B). Preëpisternum and mesepisternum imbricate. Metepisternum dull, imbricate and impunctate. Hypoepimeron inflated, dull, glabrous, weakly imbricate and impunctate. T1 dorsal surface shining, appears impunctate but with minute, moderately sparse punctures (IS = 2–3 PD). T2 shining with similar punctures to T1.

Structure. Face short (FL/HW ratio 0.79 (± 0.05 SD)). Eyes convergent below [UOD/LOD ratio 1.08 (± 0.03 SD)]. Median ocellus width/ocellocular distance ratio [MOW:OOD ratio 0.54 (± 0.3 SD)]. Clypeus extends ~50% below suborbital tangent, clypeus length/width ratio 0.50 (± 0.09 SD). Clypeus with apicolateral denticles. Gena narrower than eye. Mandible short, almost reaching opposing clypeal angle. Protibial spur with apical serrations longer than length to width of malus. Inner metatibial spur coarsely pectinate with 3 oblique, well separated, pointed teeth, tooth length up to 5 times width of rachis ( Fig. 17C). Distance between parapsidal line (at the starting point) 0.84 (± 0.03 SD) mm. Pronotal angle rounded and weakly projected. Mesoscutum length/width (widest point) ratio 0.74 (± 0.07 SD). Mesoscutum/mesoscutellum length ratio 2.57 (± 0.15 SD). Mesoscutellum/metanotum length ratio 2.00 (± 0.13 SD). Stigma small, 0.77 mm long, 0.26 mm wide (ratio ~2.96 (± 0.05 SD)), margin in marginal cell convex, marginal cell 1.13 mm long, 0.36 mm wide, free portion about 2.2X that subtended by submarginal cells (0.79 mm: 0.36 mm). 1m-cu almost meets second submarginal cell at 1rs-m. Stigma perpendicular goes about middle of third submarginal cell.

Male. Unknown. Range. Occurs in SE Queensland and coastal New South Wales ( Fig. 16). Flight period.. This species has been collected in the months of February and March as well as December. Floral hosts. ASTERACEAE : Erigeron floribundus . CAMPANULACEAE : Lobelia trigonocaulis . COMMELINACEAE : Pollia crispata . DILLENIACEAE : Hibbertia scandens MALVACEAE : Argyrodendron actinophyllum . SOLANACEAE : Solanum .

Subgenus Evyloides New Subgenus