Lasioglossum (Chilalictus) orbatum (Smith)

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 : 160

Lasioglossum (Chilalictus) orbatum (Smith)

( Figs. 12F ; Walker 1995, pp. 193–194, figs. 132 A–H)

Halictus orbatus Smith 1853: 58-59 .

Halictus viridarii Cockerell 1930: 42 . syn. by Walker 1995: 193. Halictus franki Friese H. 1924 syn. nov.; Cockerell 1929: 13. Lasioglossum (Chilalictus) orbatum – Michener 1965: 177. Lasioglossum (Chilalictus) viridarii – Michener 1965: 177. Lasioglossum (Australictus) franki – Michener 1965: 165.

Remarks: in the present study, the TYPUS of Halictus franki could not be located. ABRS (2022b) lists the type of Halictus franki as in AMNH. A search of the AMNH Invertebrate Zoology database for “ Halictus franki ” returned “Objects 0” result ( AMNH, 2022a) and a search for just “franki ” returned one result for Paracolletes franki Cockerell 1929 ( AMNH 2022b).

The description of Halictus franki lists the TYPUS sex and location as “ ♀ Freemantle (sic Fremantle), 20 July 1906 Frank leg”. This study has determined that for valid Lasioglossum (Australictus) species, the subgenus occurs only along the east coast of Australia and a few records in SE South Australia (figs. 12A–E). If this species does belong to the subgenus Australictus , it would suggest the TYPUS location label for Halictus franki in Western Australia (Fremantle) is doubtful.

While searching for the Halictus franki TYPUS specimen in AMNH, a Friese specimen, missing the metasoma, labelled as TYPUS was located (this specimen was borrowed and examined) with Friese’s handwritten label as “ Halictus ” and with an unpublished Australian place-based species name. This specimen has the following labels in descending order: the location label of “ Australia: Sydney, 14.9.06 Frank”; a Friese handwritten species name label with “1909 Friese det”; a printed orange TYPUS label; a printed AMNH registration number of “ Am. Mus. Nat. Hist. Dept. Invert. Zool. No. 26905”; a handwritten Cockerell determination label; and an undated, typed and handwritten label stating “ Lasioglossum [typed] Australictus [handwritten] det. G.C. Eickwort ” .

Below the orange Friese TYPUS label is a Cockerell handwritten label with “ Halictus franki ”. Cockerell (1929: 13) examined this specimen and under the species name “ Halictus franki ”, wrote these remarks:

A second specimen, which has lost the abdomen, but is evidently the same species, is labeled (sic) Sydney, 14.9.06 (Frank). It carries a manuscript name by Friese referring to it as Australian. I assume that Friese withdrew the latter from publication, finding it to be identical with H. franki . The hind spur has short noduliform teeth. The mesothorax is excessively densely punctured all over.

Cockerell’s (1929) remarks and his handwritten specimen label of Halictus franki on the unpublished Friese named specimen provide an insight into the actual species Halictus franki . Examination of this unpublished Friese TYPUS specimen confirmed that it is Lasioglossum (Chilalictus) orbatum . The identification was confirmed by the specimen having the following subgeneric and species characters. Subgeneric characters: mandibular preapical tooth is not enlarged or elongated but of typical Chilalictus length and shape; anterior metatibial spur is typical of Lasioglossum (Chilalictus) species (i.e. one large basal tooth followed by a wavy margin to the apex). Species characters: mesoscutum punctation is typical of L. (Chilalictus) orbatum ; shape of dorsal surface of the metapostnotum is diagnostic for L. (Chilalictus) orbatum (i.e. lateral margins of metapostnotum expanded at level of dorsal surface). Only five species of Chilalictus have this type of metapostnotum sculpture ( Walker, 1995: 193), and the Sydney location is within the known distribution for L. (Chilalictus) orbatum (fig. 12F). From the identification of this specimen, I conclude that Halictus franki is a synonym of Lasioglossum (Chilalictus) orbatum , a species which is restricted to the east coast of Australia ( Walker, 1995, fig. 12F).

Figures

Figure12.Species distribution maps:A,Lasioglossum (Australictus) davide; B,Lasioglossum (Australictus) lithusca; C,Lasioglossum (Australictus) peraustrale: D, Lasioglossum (Australictus) plorator; E, Lasioglossum (Australictus) tertium; F, Lasioglossum (Chilalictus) orbatum.