Notorisa, Mathis & Zatwarnicki, 2023

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2023, Phylogeny and Taxonomy of the Risa Genus-group (Diptera: Ephydridae), with Description of a New Genus from Australia, Records of the Australian Museum (Rec. Aust. Mus.) 75 (1), pp. 1-23 : 5-7

Notorisa gen. nov.

urn:lsid:zoobank.org:act:3B1C2CEC-63AE-4746-ACB0-19D2B2582A46

“Genus E”. D. K. McAlpine, 2002: 5–6; 2011: 9–10 [discussion of antennal morphology].

Type species: Notorisa mcalpinei sp. nov., by present designation and monotypy.

Diagnosis. Small to moderately small shore flies, body length 1.90–2.80 mm; generally dark colored, shiny ( Fig. 2 ); mouthparts geniculate, with long haustellum and rather short labellum ( Figs 5–7 ); wing venation normal ( Fig. 8 ).

Head: Frons about as high as wide; ocellar triangle long and narrow, extended to anterior margin of frons, shiny ( Figs 3, 4 ); ocellar setae well developed, proclinate, slightly convergent; pseudopostocellar setulae divergent; both medial (= inner) and lateral (= outer) vertical setae well developed; fronto-orbital setae 3, 2 proclinate, with anterior proclinate seta much larger, 3–4 times length of smaller, posterior proclinate seta, 1 large reclinate seta, length subequal to large proclinate seta; frons otherwise with few setulae above and near antennal base ( Figs 4 , 20 ). Antenna moderately elongate ( Figs 5–7 ); antennal ratio about 0.4; basal flagellomere ratio 2–2.5; pedicel lacking a well-developed, spine-like seta anterodorsally; pedicel elongate with lobe on medial side of dorsal seam more prominent than on lateral side; distal articular surface less deeply concave, lacking any suggestion of a cup-like cavity; conus relatively narrow but strongly projected, arising close to medial dorsal lobe; foramen faces laterally; basal flagellomere has no basal stem, basal foramen on a slight scabrous prominence on lateral margin of basal hollow, hollow capacious tilted medially, and its floor with a narrow caecum-like extension; pore of sacculus in a ventral position; beyond base of arista; arista about as long as antenna, rather thick at base, bearing short dorsal hairs. Face vertically carinate ( Figs 5 , 7 ), carina produced toward ventral margin as a rounded point; 1 large facial seta near ventral margin; ventral margin of face concave. Clypeus exposed in ventral facial emargination. Gena low, gena-to-eye ratio about 0.8; 1 large genal seta. Eye vertically oval, higher than width, appearing bare of interfacetal setulae. Proboscis geniculate but with length of labellum slightly more than half haustellum; 7 pseudotracheae ( Fig. 10 ); 7 medial sensillae; 6–7 ventral sensillae ( Figs 11, 12 ); palpus black; lacinia digitiform, bearing numerous setulae ventrally ( Fig. 10 ).

Thorax: Mesonotum generally dark, bronzish black, more golden bronze on scutellum ( Figs 2, 3 , 6 ); scutellum as long as wide, not extended over most of abdomen. Chaetotaxy as follows: acrostichal setulae in 5, more or less regular rows and with 1 well-developed, prescutellar pair; only posteriormost dorsocentral seta well developed; 1 postpronotal seta; 1 presutural supra-alar seta; 1 postsutural supra-alar seta; 1 postalar seta; 2 notopleural setae; 2 marginal scutellar setae; 1 proepisternal seta; 1 proepimeral seta; 2 anepisternal setae along posterior margin, ventral seta longer; 1 katepisternal seta ( Figs 5 , 6 ). Wing generally hyaline to faintly milky white ( Fig. 8 ), not darkened at base or elsewhere; costa long, extended to apex of vein M; vein R 4+5 long, reaching costa close to wing tip; wing apex slightly truncate; vein M reaching margin slightly after wing apex; coloration of all veins similar, yellow to brownish yellow; R stem vein lacking setulae dorsally; crossvein dm–cu present, distinct, mostly straight or shallowly arched, not angulate; costal setulae numerous, arranged in 2 more or less equal rows (anterodorsal and anteroventral rows), extended to vein R 4+5. Halter whitish yellow. Coxae, trochanters, femora, and tibiae dark greenish black; tarsi predominantly yellow, becoming brownish on apical 2–3 tarsomeres.

Abdomen: Male with tergites and sternites 1–5 well developed, each tergite with a spiracle in ventral margin; spiracle 6 in membrane adjacent to genital capsule; sternite 2 simple, rectangular with anterior margin even. Male terminalia ( Figs 16–19 ): Epandrium well developed, in lateral view ( Fig. 16 ) widest at midheight, ventral margin rounded; cercus ( Figs 16, 17 ) long and narrow; gonostylus a narrow, moderately wide sclerotized structure beyond ventral margin of epandrium ( Figs 16, 17 ); pregonite a well-sclerotized structure, wider basally, tapered toward ventral apex; subepandrial plate very shallowly arched, simple, band-like; postgonite clavate, apex rounded, bearing 5–6 setulae; aedeagus and phallapodeme broadly fused at juncture; aedeagus bearing a lateral keel in lateral view ( Fig. 19 ), as a scoop shovel in ventral view ( Fig. 18 ); phallapodeme in lateral view ( Fig. 19 ) with keel long, narrow; hypandrium large, as wide and almost as long as epandrium, pocket-like. Female: Tergites 6–8 narrow, transverse bands; tergites 6–7 bearing several setulae along posterior margin, but not fringe-like; sternites 4–8 subequal in width, bearing numerous setulae; cerci present; subanal plate present ( Fig. 13 ); 8 sternites evident; ventral receptacle large, well developed, sclerotized, with a helmet-shaped operculum and curved stalk, not bearing ventral appendages ( Fig. 14 ); spermathecae and accessory glands reduced to 4 short, delicate, transversely ridged ducts; dorsal wall of vulva with a narrowly V-shaped sclerotized structure, vertex anterior.

Etymology. Notorisa is a combination of “notios,” which is Greek for southern, and Risa , which is also of Greek derivation and means nose (Becker, 1907:404), in reference to the pronounced facial carina.

Distribution. Notorisa is known to occur thus far only on the island continent of Australia, where it is reasonably widespread (see below).

Discussion. This distinctive genus was first noticed by D. K. McAlpine (2002, 2011, = his “Genus E”), who showed us specimens while on a visit to the Australian Museum. David had collected several specimens and had accumulated others, which he set aside as an unusual and probably undescribed genus of shore flies. He had labelled the series with “? Ephydridae .” By good fortune and coincidence, we had begun a study of Risa a few months before our field work in Australia and we immediately recognized a close resemblance with Risa . We further observed that in many features Notorisa is intermediate between Risa and other genera of Psilopini , especially those that have an association with Amaranthaceae . Our subsequent, more detailed studies have confirmed that this similarity has a phylogenetic basis, reflecting our proposal of a sister-group relationship.

As noted on the cladogram ( Fig. 1 ) and generic diagnosis above, Notorisa is characterized by having a digitiform lacinia that bears numerous setulae ventrally ( Fig. 10 ). The finger-like lacinia is a synapomorphy for Notorisa . Other genera in Psilopini , including species of Risa , have a narrowed and tapered lacinia.

Figures

Figure 1. Cladogram and synapomorphies depicting phylogenetic relationships for lineages related to the Risa group of genera.

Figures 2–5. Photographs of Notorisa mcalpinei sp. nov. (2) Habitus, dorso-oblique view. (3) Head and thorax, dorsal view. (4) Head, anterior view. (5) Head and thorax, lateral view. Scale bars = 0.5 mm.

Figures 6–9. Photographs of Notorisa mcalpinei sp. nov. (6–8) and Risa longirostris Becker (9). (6) Head, thorax and abdomen, anterooblique view. (7) Head, lateral view. (8) Wing. (9) Wing. Scale bars = 0.5 mm.

Figures 20–25. Line drawing of frons and associated setae, dorsal view. (20) Notorisa mcalpinei sp. nov. (21) Risa longirostris Becker. (22) R. asiatica Ozerov. (23–25) Line drawing of head, lateral view. (23) R. longirostris Becker. (24) R. brevicornis Papp. (25) R. longicornuta Papp.

Figures 10–15. Photographs of Notorisa mcalpinei sp. nov. (10–14) and Risa longirostris Becker (15). (10) Proboscis, lateral view. (11) Labrum, posterior view. (12) Cibarium, posterior view. (13) Terminal female abdominal segments, ventral view. (14) Ventral receptacle, lateral view. (15) Ventral receptacle, lateral view. Scale bars = 0.2 mm (10–11), = 0.1 mm (12–13), = 0.05 mm (14–15).

Figures 16–19. Male terminalia of Notorisa mcalpinei sp. nov. (16) Epandrium, cerci, gonostylus, ventral view. (17) Same, lateral view. (18) Internal structures (postgonite, hypandrium and aedeagus fused with phallapodeme), ventral view. (19) Same, lateral view. Scale bar = 0.1 mm.