Vockeroth, J.R. (1969) A revision of the genera of the Syrphini (Diptera: Syrphidae). Memoirs of the Entomological Society of Canada 62, 176 pp.
Citrogramma notiale Vockeroth
Rather small species with black facial stripe, large brown triangle on scutellum, entirely trichose wing, preapical tuft of setulose black hairs on hind femur, and enlarged male terminalia without processes on sternite 8 or tergite 9.
Adapted from original description (Vockeroth 1969).
Head. Facial tubercle rather broad, indistinct above. Front, face, gena, and lower fourth of occiput yellow, the face with a narrow black median vitta extending to antennae. Occiput otherwise black, white-haired, densely silver pollinose behind eyes on middle half. Vertical triangle black-haired. Hairs of front and of face beside antenna black; remainder of face, and gena, white-haired. Antenna yellow-brown, basoflagellomere narrowly darker above.
Thorax. Scutum black on disc, with very fine subshining grey-brown pollen and with a pair of indistinct broad submedian blue-grey vittae, laterally with broad entire bright yellow vitta, slightly wider than postpronotum and notopleuron, extending from anterior margin of postpronotum to scutellum. Scutellum pale brown, a narrow anterior and broad posterior margin bright yellow. Pleura black, subshining, faintly silvery pollinose, much of dorsal portion bright yellow as follows: anterior flat part of anepisternum and portion of katepisternum directly below it, posterior half of posterior convex portion of anepisternum, dorsoposterior corner and indistinct ventral posterior corner of broad upper margin of katepisternum (this yellow area is narrowly separated from that on the anterior part of katepisternum), upper convex portion of hypopleuron,anatergum , lower posterior corner of hypopleuron (metathoracic episternum and epimeron), and metasternum. Postnotum black. Scutal pile white or yellow except for a few brown or black hairs in front of scutellum and on postcallus; scutellar hairs black, those on the margin longer and almost bristle-like; pleural hairs yellow. Scutellar fringe moderately dense, almost complete. Dorsal and ventral katepisternal pile patches broadly confluent over anterior half of their length, well separated on posterior half. Meron without hairs in front of spiracle. Metasternum with a few long hairs. Wing membrane entirely microtrichose. Stigma yellow-brown. Legs: Pro- and mesolegs dark yellow, the tarsi becoming dark brown apically; metaleg with coxa and trochanter mostly bright yellow but slightly darkened anteriorly, femur black with only extreme apex slightly brownish, tibia dark brown, tarsus dark brown, becoming blackish apically. Metafemur at 7/9 its length with a postero-ventral tuft of erect black setulose hairs, the longest of which are about 1/3 as long as femoral diameter; tuft preceded by slightly shorter black hairs which become longer and slightly sparser towards base of femur; legs otherwise without distinctive vestiture.
Abdomen not wider than thorax, almost parallel-sided, very slightly narrowed at apex of tergum 2, with a weak margin on terga 3 to 5. Terga discoloured in paratype, tergum 4 slightly deformed in holotype, markings as follows: tergum 1 black with lateral margins or extreme posterolateral corners yellow; tergum 2 black with a pair of large well-separated yellow-orange maculae which reach the anterior margin narrowly or broadly laterally; terga 3 and 4 black, becoming reddish or reddish-brown posteriorly, each with an entire yellow transverse fascia which becomes considerably broader laterally; tergum 5 in holotype yellow with narrow anterior fascia and large posterior triangle reddish brown, in paratype entirely reddish. Sterna yellow, without distinct markings.
Terminalia reddish, considerably enlarged. Cercus very long and slender, with four or five stronger and many weaker hairs. Surstylus produced strongly forward, attached along almost entire lower margin of tergite 9, slightly broader posteriorly, with posterior margin produced strongly mediad and bearing a swollen densely haired club-like apical process and a weak triangular apicolateral ridge in front of this process; lower margin with a few short coarse setulae on about median third, posterior margin with abundant hairs above club-like process. Sternite 9 greatly reduced, in ventral view with ventral surface reduced to a sharp lateral margin on posterior 2/3, anterior 1/3 well developed, with strong internal ridges and long broad narrowly-triangular lingula projecting caudad about half the length of the posteroventral emargination. Superior lobe strongly compressed, almost parallel-sided, rounded apically, with a few short setae on lower margin. Aedeagal base very short, slightly broader basally, open ventrally, with a small triangular dorsolateral process on each side near base. Distal portion of aedeagus very complex; just beyond base with an elaborate ventral process which has a pair of rather weak, compressed, ventrally fimbriate posterior ridges which curve anterolaterad and merge at their base with a flattened, finger-like, slightly curved, ventrolaterally directed process; remainder of aedeagus continuing posterodorsad as a moderately stout, weakly sclerotized tube, with the anterodorsal surface more strongly sclerotized and at about 2/3 its length dividing into a pair of slender tapering rods which are slightly unequal in length and curvature.
Very similar to male, differing as follows: vertex behind ocellar triangle and upper fifth of front black, this colour extending forward along sides of front, becoming narrower anteriorly and ending shortly above antennae; swollen area above antenna brownish black; front otherwise bright yellow. Antenna yellow-orange, basoflagellomere narrowly to broadly brown above; arista black. Submedian vittae of scutum bright steel-blue, becoming obscure near scutellum. Pleura as in male except that anepimeron is black only anterodorsally or entirely yellow, and posterior convex portion of anepisternum may be only obscurely brownish anteriorly. Metacoxa entirely yellow. Abdomen not at all narrowed subbasally, widest at end of tergum 2, markings similar to those of male but the yellow fasciae considerably narrower and the black posterior fasciae of terga 2 to 5 each opaque on approximately anterior half and strongly shining on posterior portion.
Citrogramma notiale is very similar to C. australe Mengual. Both species occur in the same region and they only differ by male genitalia. Although very similar morphologically, male genitalia of these two species are completely different and much modified. Citrogramma arisanicum, from Taiwan, keys close to them but it is very different: metafemur is mainly yellow, black on distal 1/3–2/5; male genitalia small; and scutellum has a brownish diffuse macula, in contrast with the perfectly defined brown macula on scutellum of the Australian species that does not reach anterior margin.
Females of C. notiale and C. australe, if any, might be indistinguishable like the males.
Citrogramma notiale is endemic to Australia, found in the Brisbane (Queensland) and Sydney (New South Wales) areas.