This subgenus was erected by Vockeroth (1969), who designated Syrphus novaezelandiae Macquart, 1855 as type-species. Following Vockeroth (1969), Austrosyrphus species have eye bare; face slightly widened and rather prominent below, with well-developed tubercle, yellow to yellow-brown, densely pollinose, with broad black medial vitta; scutum shining black with notopleuron slightly pollinose; scutellum yellow-brown to dark brown, with well-defined pollinose band on about anterior 1/6; pleura black, moderately to densely pollinose; dorsal and ventral katepisternal pile patches broadly separated throughout; metacoxa without tuft of pile at posteroventral apical angle; terga 2 to 4 each with a pair of subtriangular, slightly oblique or (novaezelandiae only) transverse and almost sub rectangular dull yellow or yellow-orange maculae, those on terga 3 and 4 rarely narrowly confluent medially; and sterna usually yellow, sometimes with dark median markings.
The male genitalia of Austrosyrphus has: Surstylus extending caudad, rather slender, nearly parallel-sided or slightly swollen at mid length, broadly rounded apically. Sternite 9 with broad and deep posteroventral emargination; lingula very broad and almost parallel-sided on about basal half, then tapering to subacute apex, the apical half thick and convex dorsally, the basal half deeply excavated on dorsal surface; emargination without swelling beside base of lingula; apex of apicolateral process of sternite broad and bluntly rounded. Superior lobe short, dorsoventrally elongate, broadly rounded dorsally and posteriorly, thick basally and thinner but not at all compressed apically, with a blunt process bearing several very small irregular marginal teeth at posteroventral angle and with a single strong hook-like tooth at anteroventral angle; a very weak lateral pre apical ridge present, ending dorsally in a weak appressed tooth; outer surface with a few moderately strong setae, inner surface without pile. Aedeagal base in the form of a short non-compressed cylinder, the dorsal surface produced caudad well beyond the base of the distal portion. of the aedeagus, the lower surface produced ventrad on each side into a broad compressed ventrolaterally directed plate with the anteroventral angle slightly more produced and twisted strongly mediad. Distal portion of aedeagus nearly tubular but with posterodorsal surface distinctly flattened, the base usually slightly broadened, the apex only obscurely membranous, produced slightly forward but not otherwise expanded, with extremely minute spicules anteriorly at apex (Vockeroth 1969).
From Thompson (2008):
"The types of novaezelandiae Macquart and ortas Walker were examined and found to represent the same species. The description of rectus Nowicki also clearly applies to this species. Under the principle of priority, the name for this species should be ortas Walker. However, as novaezelandiae has far more widespread use, being the only name of the three that has been used as valid (with the exception of catalogs and checklists) in the last 80 or more years (exactly since Miller 1921), the name is eligible to be preserved under the plenary powers of the International Code of Zoological Nomenclature (Art. 81; ICZN (1999)). Normally, I (FCT) am against preserving junior synonyms, but as the name novaezelandiae is most appropriate for this species, the second most common New Zealand flower fly, and has become the basis of the common name, the New Zealand flower fly, I feel that an exception for its preservation should be made.
The original spelling of the epithet was "novae zelandiae" based on material collected from "Nouvelle-
Zelande." Subsequent authors have misspelt the epithet, but there is no basis for an emendation or is there sufficient usage to adopt the spelling novaezealandiae."
Synonyms:
Syrphus novaezelandiae Macquart, 1855: 115.
Syrphus novaeselaniae: Kertész 1910: 123 (subsequent misspelling).
Syrphus ortas Walker, 1849: 585.
Syrphus rectus Nowicki, 1875: 24.
New description:
MALE.
Head: Face with facial tubercle, yellow with medial broad dark vitta not reaching antennal bases, black pilose, densely white pollinose laterally; gena yellow, yellow pilose, white pollinose; frontal triangle black, black pilose; holoptic, eye bare; vertical triangle black, black pilose; antenna dark brown, basoflagellomere orange ventrally; occiput black, white pollinose, withepilose ventrally, yellow pilose dorsally.
Thorax: Scutum shiny black, densely white pollinose anteriorly and laterally, mainly yellow pilose, black pilose laterally; postpronotum bare; notopleuron densely white pollinose; scutellum yellow, black pilose, densely white pollinose anteriorly, subscutellar fringe complete with long yellow pile. Pleuron black, densely white-golden pollinose, white pilose except posterior anepisternum black pilose posterodorsally; katepisternum without anteromedial pile patch, with dorsal and ventral pile widely separated; metasternum bare; calypter whitish, brownish dorsally; plumula white; halter yellow, capitulum dark; spiracular fringes white. Wing: Wing membrane hyaline, microtrichose except bare on basal half of costal cell, cell BM and before RS furcation on cells R and R1, cell CuP bare basally. Alula broad, microtrichose. Legs: Entirely dark brown to black, femur-tibia joints more yellow.
Abdomen: Parallel-sided, unmargined. Dorsum mainly black or dark brown, terga 2-4 with two subbasal lateral yellow maculae covered by white pollinosity, broadly separated; terga 1and 2 white pilose, tergum 2 with some black pile posteriorly, tergum 3 black pilose except laterally pale pilose on anterior 1/2; terga 4 and 5 black pilose, except tergum 4 pale pilose on anterolateral 1/4; tergum 5 black.
FEMALE.
Similar to male, with frons shiny black, white pollinose laterally, and tergum 5 black with two basal triangular yellow maculae covered by white pollinosity.
Melangyna (Austrosyrphus) novaezelandiae (Macquart, 1855).
Macquart, P.J.M. (1855) Dipteres exotiques nouveaux ou peu connus. 5e supplement. Mémoirs de la Société Royale des Sciences, de l'Agriculture et des Arts, de Lille (2) 1: 25-156, 7 pls.
unless otherwise stated