Risa (Risa) kotrbae, Mathis & Zatwarnicki SMNH, 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 : 20-21

Risa (Risa) kotrbae sp. nov.

urn:lsid:zoobank.org:act:14EEDD8C-B16C-4904-B35A-B8472A374C11

Figs 57–64

Diagnosis. This species is distinguished from congeners by the following combination of characters: Small shore flies, body length 1.40–1.56 mm.

Head: Structure: Face high, with shallow carina ( Figs 58, 60 ); antennal ratio ⅕; basal flagellomere ratio about 2; aristal hairs very short; labellar ratio about 1–1.2. Coloration: Antenna as for genus; palpus black; head otherwise black; ventral portion of frons, including apex of ocellar triangle, parafacial and lateral margin of face including antennal groove conspicuously whitish to silvery microtomentose ( Figs 57, 58, 60 ); most of ocellar triangle bare, shiny. Chaetotaxy: Medial-to-lateral vertical setal ratio 2–3; fronto-orbital setae 3 (rarely 2 or 4), proclinate, small, hair-like, equal or subequal in size.

Thorax: Scutum rather densely microtomentose. Prescutellar acrostichal setae lacking; 1 anepisternal seta present; scutellar disc bearing sparse and scattered setulae ( Fig. 60 ). Wing: costal setulae few and sparse. Wing length: 1.16–1.40 mm. Halter yellow. Legs as in generic description.

Abdomen: Entirely dark. Male: Male terminalia ( Figs 61–64 ): Epandrium in posterior view ( Fig. 61 ) rectangular with dorsal margin produced medially, lateral margins sinuous, ventral margin slanted medioventrally, bearing 2 narrow pregonital projections medially, these tapered and with apices recurved, in lateral view ( Fig. 62 ) epandrium much longer than wide, with angulate projection at dorsal third, ventral postgonal projection with posterior recurve thumb-like, length of recurve about half total height of surstylar projection, epandrium bearing 6–8 setulae in cluster toward base of ventral projection; cercus in posterior view ( Fig. 61 ) rectangular, dorsal margin slightly produced mediodorsally, basal margin fused with ventromedial margin of epandrium, bearing setulae along length, in lateral view ( Fig. 62 ) distinctly narrowed dorsally, and curved anteriorly, thereafter ventrally slightly expanded, narrowly spatulate before ventral fusion with epandrium; aedeagus in ventral view ( Fig. 63 ) elliptical, elongate, phallapodeme fused to base, in lateral view ( Fig. 64 ) aedeagus narrowly digitiform, apical half slightly wider than base, rod-like, fused phallapodeme irregularly bifurcate at base, with longer process, narrow, digitiform, other process wider at base, tapered to point apically; internally with subepandrial plate at medial base of epandrium, in ventral view ( Fig. 61 ) sclerite wider than long, base shallowly projected medially, rest of arch deeply bifurcate, each lateral projection bearing a postgonite, latter shallowly digitiform, bearing 2–3 apical setulae, in lateral view ( Fig. 64 ) with irregular quadrate base with rounded corner toward base, thereafter apically as trifurcate with postgonite as medial projection; hypandrium in ventral view ( Fig. 63 ) pentagonal with base truncate and sharply angulate at basolateral corners, posterior half evenly angled medially, medial margin broadly rounded, in lateral view ( Fig. 64 ) slipper-like, tapered and shallowly curved posteriorly to pointed apex. Female: Tergites 6–7 bearing row of fringe-like, long setulae along posterior margin; tergite 8 bare, in 3 sections, interrupted dorsolaterally; sternite 8 transversely oval (length/width ca. 0.5); middle of sternite 8 with a shallow, transverse, truncate protrusion separating setulose anterior ⅘ of sternite from bare posterior margin; anterior portion bearing about 28 stout, black setae in more than 2 irregular rows toward anterior margin; setae relatively long with pointed apices curved anteriorly; posteriorly anterior portion bearing fringe of long, apically hooked setulae; subanal plate present, triangular; ventral receptacle lacking paired tubular appendages; cerci short, rounded.

Type material. The holotype ♂ of Risa kotrbae is labelled “ ISRAEL [.] Ẕomet Zohar [31°08.5'N 35°21.6'E], 9. vi. 1997 [9 Jun 1997,] A. FREIDBERG [white]/ HOLOTYPE ♂ Risa kotrbae Mathis & Zatwarnicki SMNH [red].” Thirty-nine paratypes ( SMNH, USNM) bear the same locality label as the holotype (additional specimens in alcohol; SMNH). Other paratypes are as follows: ISRAEL. Kalya (31°45'N

Mathis & Zatwarnicki: The Risa genus group of ephydrid flies 21

35°28'E; ex Suaeda palaestina Eig & Zohary ), 9 May–28

Sep 1995, 1996, A. Freidberg, B. Merz, I. Yarom (22♂, 15♀; SMNH) ; Na h al Qidron (31°47.1'N 34°38.1'E; Rt. 90), 7 Jun–10 Jul 1996, A. Freidberg, B. Merz (33♂, 22♀; SMNH; additional specimens in alcohol; SMNH); Ẕomet Me z ada (31°18.8'N 35°23'E; swept from Suaeda fruticosa Forsskål , occasionally from S. palaestina ), 10 Jul 1996, A. Freidberg (28♂, 5♀; SMNH) .

Type locality. Israel. Ẕomet Zohar (31°08.5'N 35°21.6'E) .

Distribution. Palearctic: Israel.

Natural history. This species is associated with Suaeda fruticosa Forsskål and Suaeda palaestina (Amaranthaceae) .

Etymology. The specific epithet, kotrbae , is a Latin genitive patronym to honor our friend and colleague, Dr Marion Kotrba, for her numerous contributions to the systematics of Diptera , especially female reproductive systems, including those for species of Risa .

ACKNOWLEDGEMENTS. We gratefully acknowledge the assistance and cooperation of many organizations and individuals who contributed to the field work and production of this paper. To the curators and collection managers noted previously who loaned specimens, we express our sincere thanks. We also thank Martin J. Ebejer (NMWC) for re-examining the type series of R. salsolae . Young T. Sohn† rendered the habitus line drawings and is thanked. For reviewing a draft of this paper, we thank Martin J. Ebejer and Marion Kotrba.

Figures

Figures 57–60. Photographs of Risa kotrbae sp. nov. (57) Head, anterior view. (58) Head and thorax, lateral view. (59) Same, dorsal view. (60) Same, dorsolatero-oblique view. Scale bars = 0.2 mm (57), = 0.5 mm (58–60).

Figures 61–64. Male terminalia of Risa kotrbae sp. nov. (61). Epandrium, cerci, gonostylus, ventral view. (62) Same, lateral view. (63) Internal structures (postgonite,hypandrium and aedeagusfused withphallapodeme),ventral view.(64)Same,lateral view.Scalebar =0.1 mm.