Lasioglossum (Australictus) davide (Cockerell)

Walker, Kenneth L, 2022, Taxonomic revision of the Australian native bee subgenus Australictus (Hymenoptera: Halictidae: Halictini: genus Lasioglossum) - “ Wood-Splitting Axe Bees ”, Memoirs of Museum Victoria 81, pp. 135-162 : 139-143

Lasioglossum (Australictus) davide (Cockerell)

( Figs. 2E , 5 A-F, 10A-B, 12A)

Halictus davidis Cockerell 1910a: 234 .

Halictus kurandensis Cockerell 1910a: 234 . syn. nov.

Halictus nigroscopaceus Friese H. 1917 syn. by Cockerell 1929:211. Lasioglossum (Australictus) davide – Michener 1965: 165. Lasioglossum (Australictus) kurandense – Michener 1965: 165. Lasioglossum (Australictus) nigroscopaceum – Michener 1965: 165.

Material examined: Holotype of davidis ♀, Queensland, Kuranda (has Cairns typed on label and Kuranda hand written), 4. 02. Turner BMNH Hym.17.a.914 ( BMNH) (view type data and image at https://data.nhm. ac.uk/object/f00271eb-7e4e-41fb-9e8d-2736fa9ff79f accessed 16 August 2022).

Holotype of kurandensis ♂, Queensland, Kuranda (Cairns typed on label and Kuranda handwritten), 4. 02. Turner BMNH Hym.17.a.956 ( BMNH) (view type data and image at https://data.nhm.ac.uk/object/ e1eec50b-a2b4-4b89-84ca-6bea23587e8e accessed 16 August 2022).

Syntypes (“ TYPUS ”) of nigroscopaceus – Queensland: Malanda , Mjöberg. All three specimens have same label and type number: Am. Mus. Nat. Hist. Dept. Invert. Zool. No. 26926 (2♀, 1♂). The male specimen has Cockerell’s handwritten label saying “ Halictus davidis Ckll ” ( AMNH) .

Other specimens examined: (13♀, 6♂): QUEENSLAND: (1♀) Upper Mulgrave 19 June 1991, J.H. Barrett, nesting in rotten log ( QDPI); (1♀) Tully Falls , S.F. 730m, 18 km SSW Ravenshoe, 7 Dec 1987 – 7 Jan 1988, R. Storey & B. Dickinson ( QDPI); (1♀) Mt Halifax summit, 45 km WNW Townsville, 4 Dec 1990 – 8 Jan 1991, A. Graham, pitfall and intercept traps ( QDPI); (1♀) Mt Halifax summit, 45 km WNW Townsville, 2 Dec 1990, A. Graham, hand collecting ( QDPI); (1♀) Mt Lewis nr Mossman , 22 Oct 1984, N.W. Rodd ( AM); (1♀, 1♂) Cairns District , F.P. Dodd ( SAM); (2♀) Kuranda , 2 Jan 1953 & 25 Sept 1954, GB ( NMV); (5♀, 3♂) Kuranda Black Mountain Forest Road, Jan 2001, K. Walker, on Lophostemon grandifloris subsp. riparius (NMV) ; (1♂) Kuranda , Jan 1952, J.G. Brooks ( AM); (1♂) Mt Spec Nat. Pk , 10 km E Paluma, 22 Nov 1988, K. Walker, on Eucalyptus (NMV) .

Floral record: Family visited: 1 ( Myrtaceae (2)). Genera visited: 2 ( Eucalyptus , (1), Lophostemon (1)).

Flight phenology capture records: Jan (3) Feb (0) Mar (0) Apr (0) May (0) June (1) July (0) Aug (0) Sept (1) Oct (1) Nov (1) Dec (3).

Diagnosis. Lasioglossum (Australictus) davide is most like L. (Australictus) plorator in body colours. This species can be distinguished, in both sexes, from other Australictus species by black body colour with bluish tinge on mesoscutum; the lack of tomentum on the mesosoma or metasoma; dorsal surface of metapostnotum posterior margin carinate, defined by raised posterior and lateral carinae; metapostnotum dorsal surface sculpture ruguloso-striolate (figs. 2E, 5A–D); male genitalia with gonobase widened basally (a characteristic shared only with L. tertium ), large retrorse lobes with small, apically rounded gonostylus (figs. 10A, 10B); and males lacking any distinctive metasomal sternal vestiture (fig. 5F). This species is restricted to North Queensland (fig. 12A).

Description of female: (figs. 5A–B, 5E) body length: 9.58– 9.68– 10.21 mm (n=10); forewing length: 2.45–2.47– 2.49 mm (n=10); head width: 2.78–2.88– 2.93 mm (n=10); intertegular width: 2.06–2.38– 2.40 mm (n=10). Relative head measurements: HW: 100, HL: 84–85, UID: 54–55, LID: 50– 52, IAD: 08–09, OAD: 21–22, IOD: 08–09, OOD: 14–15, CL: 19–21, GW: 18–20, EW: 20–22, SL: 37–40, FL: 63–65.

Head: (fig. 5E) inner eyes margins weakly narrowed basally; median frontal carina reaching less than one third way to median ocellus; clypeus entirely polished and smooth, anterior half weakly concave medially, sparsely deeply punctate, punctures rounded to elongate; supraclypeal area distinctly raised above paraocular area, polished, smooth, punctures small, round and open with small rounded punctures; frons sculpture above antennal bases smooth but dull, microtessellate with small punctures for setae insertion points, paraocular area smooth and closely punctate.

Mesosoma: (fig. 5A) mesoscutum anterior mesial margin weakly produced mesoanteriorly, surface smooth with dull, “oily” sheen, medially openly punctate, laterad of parapsidal areas closely punctate, parapsidal areas and posterior margin densely punctate; scutellum 2 x as long as dorsal surface of metapostnotum, scutellum smooth, with dull sheen, weakly, openly punctate; dorsal surface of metapostnotum carinate (fig. 2E), posterior margin with well-defined, raised, semicircular carina and posterolateral carinae, dorsal surface transversely ruguloso-striolate medially, striate laterally, sculpture reaches posterior carina, lateral margins smooth microalveolate, vertical posterior surface of metapostnotum defined by lateral carinae meeting dorsal surface posterolateral carinae; mesepisternum and metepisternum plicate; first recurrent vein (1m-cu) meeting 1rs-m vein or entering second submarginal cell.

Metasoma and legs: (figs. 5A, 5B) metasomal T 1– T 5 dull, smooth, closely to densely punctate with minute punctures; anterior metatibial spur finely serrate to simple, with no distinct teeth.

Colour: (figs. 5A, 5B) body and legs black except mesoscutum and scutellum dark “oily” grey with bluish tinge.

Vestiture: (figs. 5A, 5B, 5E) sparse, clypeus and supraclypeal area glabrous, frons with sparse small, black, erect hair; mesoscutum and scutellum almost glabrous but with sparse small, black, erect hair; long hair on lateral, vertical posterior surface of metapostnotum; apical one third of T 1 with long, erect, white hair, remainder of T 1 and T 2 glabrous, T 3 and T 4 with some black, adpressed hair apically. Description of male: (figs. 5C, 5D, 5F) body length: 7.07–8.45– 8.79 mm (n=6); forewing length: 1.94–2.48– 2.54 mm (n=6); head width: 1.82–2.42– 2.50 mm (n=6); intertegular width: 1.44– 2.15– 2.21 mm (n=6). Relative head measurements: HW: 100, HL: 88–89, UID: 56–57, LID: 42–43, IAD: 12–13, OAD: 23–24, IOD: 15–16, OOD: 14–15, CL: 26–29, GW: 16–18, EW: 28–29, SL: 20–23, AF4/AF2+3 (18/14, 20/14) 1.29–1.43, FL: 178–180.

Differs from female as follows: inner eyes converging more basally; median frontal carina reaching about one quarter to median ocellus; frons sculpture reticulate across surface to inner margins of eyes; scape reaches basally level of median ocellus; clypeus surface shiny weakly microtessellate basally, medium area rounded not concave, openly punctate, supraclypeal area protruding above paraocular area, supraclypeal area bulbous, shining, openly to closely punctate; mesoscutum surface similar to female in colour but densely punctate medially, openly punctate laterad of parapsidial areas, densely punctate in parapsidal areas and anterolaterally; scutellum shiny as in female but closely punctate; dorsal surface of metapostnotum same as in female, posteriorly carinate, dorsal surface ruguloso-striolate; apical two thirds of clypeus pale yellow and metasoma in some specimen with distinct blue tinge.

Vestiture: frons hair dense, erect, black; paraocular area hair sparse, white, adpressed; mesoscutum appearing glabrous but with sparse, short, erect, black hair; metapostnotum lateral sides with short, white, adpressed hair; apical posterior vertical posterior surface of metapostnotum glabrous; metasomal sterna with moderately dense, short erect and adpressed black setae, no distinct patterns observed (fig. 5F).

Genitalia: (figs. 10A, 10B) gonobase widened basally, complete ventroapically, gonocoxa wider and longer than gonobase, with sparse, erect setae dorsoapically, glabrous ventrally, dorsal inner margins of gonocoxa basally rounded, apical inner margin not produced continuing contour of gonostylus, glabrous; retrorse lobes large, overlapping at midline, membranous, basal inner margins with short setae, apical inner margins of retrorse lobes glabrous; gonostylus small (about one third length of gonocoxa) erect, small, apically rounded, with sparse short setae; penis valves curved apically, with short dense hair dorsolaterally.

Distribution: (fig. 12A) the species is restricted to north Queensland between approximately Townsville to Cairns.

Remarks: Cockerell (1929: 211) synonymised Halictus nigroscopaceus with Halictus davidis ; however, Michener (1965: 165) listed Lasioglossum (Australictus) nigroscopaceum as a valid species. Cockerell’s (1929) synonymy was checked and accepted here. Due to the restricted distribution of this species, fewer than 20 specimens were located for this study. The only significant variation observed was in the body length of males (7.07 mm to 8.79 mm). Lasioglossum davide and L. tertium are the only two Australictus species in which the gonobase is widened basally (figs. 10A, 11C); in the other three Australictus species, the gonobase narrows basally (figs. 10A, 10E, 11A).

Figures

Figure 2. A, Lasioglossum (Australictus) lithusca female labrum; B, Lasioglossum (Australictus) tertium female anterior metatibial spur; C, Lasioglossum (Australictus) peraustrale male vertical metapostnotum tomentum; D, Lasioglossum (Australictus) tertium, banded male metasoma form; E, Lasioglossum (Australictus) davide female dorsal surface of metapostnotum; F, Lasioglossum (Australictus) plorator female dorsal surface of metapostnotum.

Figure 5. A–F Lasioglossum (Australictus) davide: A, dorsal female; B, lateral female; C, dorsal male; D, lateral male; E, female head front; F, male vestiture on metasomal sterna.