Microphorella irwini, Brooks & Cumming, 2023

Brooks, Scott E. & Cumming, Jeffrey M., 2023, The first Neotropical and Afrotropical species of Microphorella Becker, with a key to the genera of Parathalassiinae and species of Microphorella from the Southern Hemisphere (Diptera: Dolichopodidae sensu lato), Zootaxa 5301 (5), pp. 581-593 : 585-590

Microphorella irwini sp. nov.

( Figs 3, 4 , 14–22 )

urn:lsid:zoobank.org:act:9419AC89-147A-4611-BC94-B5FED3EDCB84

Type material. HOLOTYPE ♁ ( Figs 14, 15 ) labelled: “SOUTH AFRICA: W. Cape: [Langeberg]/ Tradouw Pass, Groot Vaders / Bosch [ South Cape Boundary ], 300m, 33°56ʹ52ʺS / 20°42ʹ26ʺE, 30.ix–22.x.2004,/ MT in meadow, Irwin, Parker,/ Hauser, CNC1099255 ”; “HOLOTYPE/ Microphorella irwini / Brooks & Cumming [red label]” ( NMSA) . PARATYPES: SOUTH AFRICA: same data as holotype except, CNC1099257 (1♀, NMSA) ; same data as holotype except, CNC1099254 , CNC1099256 , CNC1099258 , CNC1099260 (2♁, 1♁ dissected, 1♀ dissected, CNC) ; same data as holotype except, CNC1099252 , CNC1099261 (2♁, CSCA) ; same data as holotype except, CNC1099253 , CNC1099262 (1♁, 1♁ dissected, USNM).

Diagnosis. Microphorella irwini sp. nov. is distinguished from other known Southern Hemisphere species of the genus by the following combination of features: head with lower margin of face projected anteriorly above frontoclypeal suture ( Fig. 15 ); thorax with tiny biserial acrostichal setae; body and legs brown with dark setation; male foreleg with curled cluster of three long setae on trochanter ( Fig. 16 ) and long posterior seta on tibia ( Fig. 15 ); male midleg with long seta on trochanter ( Fig. 16 ); male wing with larger costal seta posterior to apex ( Figs 17, 18 ); female terminalia ( Fig. 22 ) with syntergite 9+10 bearing acanthophorous setae, female cercus with broadly rounded apex, setose with longer apical setae.

Description. Male ( Figs 14–21 ): Body length 1.7 mm, wing length 1.5 mm (based on Figs 14, 17 ). Head ( Figs 14–16 ): Brown, frons and face coppery greenish-brown in anterior view, vertex and occiput coppery-brown to blackish depending on angle of examination; as wide as thorax in dorsal view; ovoid in lateral view (higher than broad); broader than high in anterior view; setae brown. Ocellar triangle conspicuous. Occiput weakly concave on upper median part. Eyes covered with short ommatrichia; medial edge of eye with small but distinct emargination adjacent to antenna; ommatidia of uniform size. Frons about 1.5X broader than high, widening above. Face broad above (about width of combined antennal bases) weakly narrowed ventrally, coppery-brown in anterior view ( Fig. 16 ), lower margin projected anteriorly above frontoclypeal suture ( Fig. 15 ). Clypeus not separated from face, higher than broad ( Fig. 16 ), deflected posteriorly and laterally flanked by protruding parafacial ( Fig. 15 ). Setae of head well differentiated: 1 pair of fronto-orbitals near level of median ocellus; 1 pair of lateroclinate anterior ocellars; 1 pair of small posterior ocellars; 1 pair of inner verticals (sometimes referred to as postocellars) apparently present (setae missing but sockets visible); outer verticals apparently absent; postocular setae fine and uniserial. Antenna ( Fig. 15 ) inserted above middle of head in profile, dark brown; scape short, funnel-shaped; pedicel slightly longer than scape, spheroidal with subapical circlet of setulae; postpedicel about 2.7X longer than pedicel, 1.7X longer than wide, drop-shaped, clothed in fine setulae; arista-like stylus apical, 1.5X length of postpedicel, with minute hairs. Palpus brown, subtriangular, about as long as wide, with fine setae. Proboscis brown, short, projecting ventrally. Gena projected below eye, with a few setae along oral margin. Thorax ( Figs 14, 15 ): Brown pruinose, setae dark brown. Mesoscutum moderately arched, prescutellar depression present. Proepisternum with 2 tiny setae. Postpronotal lobe with 1 tiny seta. Mesonotum longer than wide. Acrostichal setae tiny, biserial, rows ending before prescutellar depression; each side of mesonotum with: apparently 7–8 dorsocentrals, anterior setae tiny (similar to acrostichals), posterior 2 setae larger, progressively longer and stronger, 1 presutural supra-alar (posthumeral), 2 notopleurals (lower seta missing in all males, but socket visible), 1 postalar and several acrostichal-sized setae above notopleuron on either side of transverse suture. Scutellum broadly crescent-shaped with 1 long, strong, posteriorly projected seta per side. Mesopleuron bare. Halter brown. Legs: Brown, with brown setae; tarsomeres 1–4 of all legs progressively shorter apically with tarsomere 5 slightly longer than 4; tarsal claws, pulvilli and empodium normally developed on all legs. Foreleg: Coxa with fine setae on anterior surface, longer at apical margin; trochanter with curled cluster of three long setae ( Fig. 16 ); femur, tibia and tarsus subequal in length; tibia with long, strong posterior seta before midlength; tarsomere 1 slightly shorter than combined length of tarsomeres 2–3. Midleg: Coxa with several setae on anterior surface and margin; trochanter with long, strong ventral seta ( Fig. 16 ), 1 long anterodorsal seta (half as long as ventral seta) and a few small setae; femur slightly shorter than tibia, basally with series of 3–4 long anterodorsal setae, apically with distinct anteroventral and posteroventral seta; tibia and tarsus subequal in length; tarsomere 1 subequal to combined length of tarsomeres 2–5. Hindleg: Coxa with 2 setae on lateral surface; femur, tibia and tarsus subequal in length; femur with series of long anteroventral setae along distal 2/3 (setae slightly longer than femur width); tibia with distinct anterior and dorsal rows of setae; tarsomere 1 subequal to combined length of tarsomeres 2–4. Wing ( Figs 17, 18 ): With brownish tinge, veins dark brown, about 2.6X longer than wide. Pterostigma absent, membrane entirely covered with minute microtrichia, alula absent. Costa circumambient. Extreme anterior base of costa with strong dorsal seta and a few shorter proximal setae. Anterior section of costa (between base and R 2+3) with double row of spine-like setae. Posterior section of costa (beyond R 2+3) with setae finer and longer, apex with 1 larger costal seta between R 4+5 and M 1 ( Fig. 18 ). Radial and medial veins complete and reaching wing margin, CuA+CuP (anal vein) very faint and short, Sc reaching costa. R 1 terminating beyond midpoint of wing distal to M 2. Base of Rs originating opposite humeral crossvein. R 2+3 subparallel with R 1 in basal 1/3, straight and subparallel with R 4+ 5 in distal part. R 4+5 and M 1 gently curved posteriorly, gradually diverging to wing apex. M 1 and M 2 divergent. M 2 and M 4 subparallel beyond cell dm. Costal section between M 1 and M 2 about 1.3X longer than costal section between M 2 and M 4. CuA rounded (convex). Crossvein r-m short, distal to base of R 4+5. Crossvein bm-m complete. Cell dm present, closed by base of M 2 and dm-m crossvein, cell extending to middle of wing. Crossvein dm-m about 3.5X longer than base of M 2. Cells br, bm and cua in basal fourth of wing. Cell cua ovoid. Anal lobe not developed. Calypter with a few fine setae. Abdomen: Brown with weak brown setae; segment 7 bare. Segments 5–7 narrowed and laterally compressed to form cavity on right side for hypopygium. Sternite 5 without process. Sternite 8 subrectangular, slightly broadening apically, with short setae, width similar to segment 7; tergite 8 indistinct. Hypopygium ( Figs 19–21 ): Concolorous with abdomen; lateroflexed to right; inverted with posterior end directed anteriorly; large, half as long as abdomen; asymmetrical; foramen not formed. Epandrium divided into left and right lamellae. Left epandrial lamella ( Fig. 19 ) partially overlapping left side of hypandrium, posterior margin trifurcate, with projecting surstylar lobes and ventral epandrial process, ventral edge fused with hypandrium but margin distinct; ventral epandrial process articulated at base, long and evenly broad with short apicomedial bifurcate tip; dorsal epandrial margin (anterior to surstylus) broadly humplike with marginal seta. Left surstylus bilobed, dorsal and ventral lobes separated by U-shaped cleft through which left postgonite lobe protrudes. Dorsal lobe of left surstylus with elongate and curved lateral seta near base, medially with tubular process (projecting behind postgonite lobe), bearing elongate, curved and modified apical seta. Ventral lobe of left surstylus broad, slightly longer than dorsal lobe, with truncate apex, medial surface with basal cluster of modified and irregularly curved setae. Right epandrial lamella ( Fig. 20 ) partially overlapping right side of hypandrium, ventral edge apparently not fused with hypandrium, as long as hypandrium; dorsal margin with broad emargination bordering ventral margin of right cercus; ventral epandrial process absent. Right surstylus bilobed, dorsal and ventral lobes separated by U-shaped cleft through which right postgonite lobe protrudes. Dorsal lobe of right surstylus narrow, digitiform. Ventral lobe of right surstylus broader and longer than dorsal lobe. Hypandrium reniform, posterior half with series of 3 setae on each side, posterior end with long, narrow, dorsally projected process ( Fig. 19 ). Left postgonite large and complex in structure, narrow basally, apex broad and multilobate ( Fig. 19 ). Right postgonite lobe large and complex in structure, multilobate ( Fig. 20 ). Phallus tubular, J-shaped, projected dorsally, preapical portion ribbed on inner surface, apex enlarged, outer surface with long, narrow process near middle. Ejaculatory apodeme moderately sized and keel-like. Hypoproct simple, left and right sides short and asymmetrical. Cerci ( Fig. 21 ) asymmetrical, right cercus larger with longer subtriangular apical projection, each cercus with humplike base bearing 3 setae and medial tubercle bearing 1 larger seta.

Female. Similar to male except as follows: Legs: Foreleg: Trochanter without curled cluster of three long setae; tibia without long, strong posterior seta before midlength. Midleg: Trochanter without long, strong ventral seta. Hindleg: Femur without series of long anteroventral setae along distal 2/3; tibia lacking distinct anterior and dorsal rows of setae. Wing: Apex without larger costal seta between R 4+5 and M 1. Abdomen: Tapering posteriorly, apical segments retractable into segment 5. Terminalia ( Fig. 22 ): Syntergite 9+10 medially divided into subrectangular hemitergites, with four acanthophorous setae on each side; cercus sclerotized, broadly rounded apically, setose, apical setae slightly longer than cercus.

Distribution. This species is known only from the type locality in Tradouw Pass, Grootvadersbosch, Western Cape, South Africa ( Figs 3, 4 ).

Etymology. This species is named after our colleague, Dr. Michael Irwin formerly of the University of Illinois, Urbana-Champaign, who headed the team that collected the type series of this new species.

Remarks. This species was collected in a Malaise trap placed on an inland windswept meadow with very low, grassy vegetation at 300 m elevation (M.E. Irwin pers. comm.). Microphorella irwini sp. nov. is the first recorded species of the genus from the Afrotropical Region and the first non-coastal parathalassiine species from the Region.

Figures

FIGURES 1–4. Known geographical distribution of Microphorella in the Neotropical Region and Afrotropical Region. 1–2. Distribution of M. amorimi sp. nov. in the Neotropical Region (Chile). 3–4. Distribution of M. irwini sp. nov. in the Afrotropical Region (South Africa).

FIGURES 14–18. Microphorella irwini sp. nov., male. 14. Habitus of holotype. 15. Head and foreleg of holotype, lateral view showing projected lower margin of face (arrow) and long posterior seta on fore tibia (arrow). 16. Fore and mid legs in ventral view (showing setae on each trochanter, arrows) and head in anterior view. 17. Wing. 18. Apex of wing, showing larger costal seta (arrow). Abbreviations: an lb—anal lobe; cua—anterior cubital cell; CuA—anterior branch of cubital vein; dm—discal medial cell; M1, M2, M4—medial veins; plp—palpus; R1, R2+3, R 4+5 —medial veins.

FIGURES 19–22. Male and female terminalia of Microphorella irwini sp. nov. 19. Hypopygium, left lateral view. 20. Hypopygium, right lateral view. 21. Male cerci and hypoproct lobes, dorsal view. 22. Female terminalia, dorsal view. Abbreviations: cerc—cercus; d sur—dorsal lobe of surstylus; epand—epandrium; hypd—hypandrium; hypd proc—hypandrial process; hyprct lb—hypoproct lobe; (L)—left; pgt lb—postgonite lobe; ph—phallus; (R)—right; tg—tergite; v epand proc— ventral epandrial process; v sur—ventral lobe of surstylus.