Microphorella similis Brooks

Brooks, Scott E. & Ulrich, Hans, 2012, Microphorella similis sp. nov. from Switzerland, a close relative of the type species, M. praecox (Loew) (Diptera: Dolichopodidae: Parathalassiinae), Zootaxa 3489, pp. 45-57 : 46-50

publication ID	https://doi.org/ 10.11646/zootaxa.3489.1.3
publication LSID	lsid:zoobank.org:pub:758682E7-1B32-4096-B4A8-8B883835D497
DOI	https://doi.org/10.5281/zenodo.6175033
persistent identifier	https://treatment.plazi.org/id/6605879A-FF81-FF90-FF27-FBAAFC5BFF69
treatment provided by	Plazi
scientific name	Microphorella similis Brooks
status	sp. nov.

Treatment

Microphorella similis Brooks View in CoL sp. nov.

( Figs. 1A View FIGURE 1 , 1B View FIGURE 1 , 2A View FIGURE 2 , 2B View FIGURE 2 , 3A–C, 4 View FIGURE 4 , 5 View FIGURE 5 , 6 View FIGURE 6 , 7 View FIGURE 7 )

Type material. HOLOTYPE 3 from Leuk-Pfynwald , Switzerland labelled: “Schweiz, Wallis [=Valais],/ Leuk-Pfynwald,/ Rhône-Kiesbett,/ 16.V.2000 H. Ulrich ”; “HOLOTYPE/ Microphorella similis / Brooks” ( ZFMK, in ethanol) . PARATYPES: 283, 29♀, same locality and date as holotype ( ZFMK, in ethanol) ; 33, 3♀, same data ( MHNG, in ethanol) ; 33, 3♀, same data ( CNC, in ethanol) ; 173, 28♀, Leuk-Pfynwald, 27.V.1999, B. Merz ( MHNG, in ethanol) ; 33, 2♀, same data ( CNC , critical-point dried and mounted on pins from ethanol).

Diagnosis. Microphorella similis sp. nov. is a medium-sized species for the genus (body length 1.4–1.9 mm), shining white when dry and with white setae, with long pointed antennae, which most closely resembles Microphorella praecox (Loew) , the type species. The characters shared with M. praecox and those differing from it are enumerated under ‘Comparison’ following the detailed description. It is easily distinguished from other species of Microphorella by the following combination of features: postpedicel ( Figs. 1B View FIGURE 1 , 4A View FIGURE 4 ) elongate, roughly conical; stylus ( Figs. 1B View FIGURE 1 , 4A View FIGURE 4 ) claw-shaped, curved ventrad and pointed, distinctly shorter than postpedicel in male, at most subequal in female; male mid leg with tarsomere 1 bowed and bearing a ventral comb-like row of hook-like setae ( Fig. 4B View FIGURE 4 ); wing venation modified with R4+5 and M1 sinuous, cell r2+3 narrowing before apex and broadening again to apex, M2 and M4 subparallel beyond cell dm, costal section between M1 and M2 distinctly longer than section between M2 and M4 ( Figs. 1A View FIGURE 1 , 3A, 3C); hypopygium with ventral epandrial process ( Fig. 6A View FIGURE 6 ) Y-shaped with ventral arm of furca thick and lacking basal hump-like projection, left postgonite lobe ( Figs. 6A View FIGURE 6 , 6E View FIGURE 6 ) with bifurcate apex, phallus ( Figs. 6A View FIGURE 6 , 6E View FIGURE 6 ) bearing pointed process near middle and lacking longitudinal serration; female terminalia ( Fig. 7 View FIGURE 7 ) with acanthophorite setae, sternite 8 with apex narrow and bifurcate, cercus rounded and setose.

Description. Male: Body length 1.4–1.7 mm, wing length 1.3–1.6 mm. Dark brown ground colour with dense greyish-white pruinosity, with faint bluish-green and bronze metallic tinges at certain angles, legs with pruinosity slightly less dense, joints and tarsi paler. Setae and pubescence of body and legs white. Head ( Figs. 1B View FIGURE 1 , 2A View FIGURE 2 ): Ovoid in lateral view; slightly broader than high in anterior view. Neck inserted slightly above middle of head. Ocellar triangle conspicuous. Occiput weakly concave on upper median part above occipital foramen. Dichoptic; eyes entirely covered with ommatrichia, medial edge with weak emargination adjacent to antenna, ommatidia smaller anterodorsally. Frons greyish, over 2X broader than high, widening above. Face and clypeus conclourous with frons. Face narrowest at middle, about 1.7–2.0X width of anterior ocellus. Clypeus not separated from face, slightly higher than broad, widening below, apical margin truncate, weakly produced. Bristles of head welldifferentiated; dorsal bristles strong: 1 pair of inclinate fronto-orbitals well-separated from base of antenna and arising very close to posterior ocellus, 1 pair of lateroclinate anterior ocellars, 1 pair of small posterior ocellars, 1 pair of strong widely spaced inclinate postocellars, 1–3 pairs of lateroclinate verticals; postocular setae short and uniserial; postgena with longer scattered setae around edge of mouth-opening. Antenna ( Figs. 1B View FIGURE 1 , 4A View FIGURE 4 ) entirely dark brown, inserted above middle of head in profile; scape short, funnel-shaped; pedicel subequal in length to scape, spheroidal with subapical circlet of setulae; postpedicel elongate, about 3X longer than wide, clothed in fine setulae, roughly conical (not bulb-shaped) but with broad basal and narrow distal portions set off against each other, broad basal portion subequal in length to narrow distal portion; stylus stout, claw-shaped (i.e. evenly tapering from base to pointed tip and gently curved ventrad), about 1/3–1/2 (rarely 3/4) length of postpedicel, with minute hairs. Palpus ovoid with lower margin straight, dark brown, clothed with minute pile, apical half with several short setulae on outer surface, sensory pit present. Proboscis short, projecting ventrally; epipharyngeal carina present; epipharyngeal blades narrow; labellum with 6 geminately sclerotized pseudotracheae. Gena narrow. Thorax: Mesoscutum moderately arched, prescutellar depression apparent. Prosternum fused with proepisternum forming precoxal bridge. Proepisternum with 1 upper setula and 1 lower setula. Antepronotum narrow with 1–2 pale setula per side. Postpronotal lobe distinct with several small setulae. Mesonotum shield-shaped in dorsal view, longer than wide, bristles well-differentiated. Acrostichal setae absent, except for 1 pair on extreme anterior margin of mesoscutum; 6–8 dorsocentral bristles (posteriormost bristle strongest, anterior bristle short), 1 presutural supraalar bristle, 3 postsutural supra-alar bristles (anteriormost bristle at suture), 2 notopleural bristles, and 1 post-alar bristle per side. Scutellum crescent-shaped in dorsal view with 1 pair of strong bristles. Mesopleuron bare. Halter pale brownish-white. Legs: Mostly clothed with white setulae, tarsal claws, pulvilli and empodium normally developed on all legs. Foreleg: Coxa with setae on anterior surface; femur slightly longer than tibia, with row of erect posteroventral setae; tibia slender with row of 4–5 long erect posterior setae, with adjacent row of erect ventral setae; tarsus slightly shorter than tibia, somewhat compressed laterally; tarsomere 1 slightly shorter than combined length of tarsomeres 2–5, lacking spinose anterior tubercle at base; tarsomeres 2–4 decreasing slightly in length apically; tarsomere 5 subequal in length to tarsomere 2, apex lacking medial finger-like process. Midleg: Coxa with row of several setae on anterior surface above apical margin; femur subequal in length to tibia, with row of 7–8 long erect posteroventral setae, lacking dense tuft of short setulae at middle third; tibia slender; tarsus shorter than tibia; tarsomere 1 bowed with ventral comb-like row of hook-like setae, with 2 strong basiventral setae and 4 short dark spine-like apicoventral setae ( Fig. 4 View FIGURE 4 B), subequal to combined length of tarsomeres 2–5; tarsomeres 2–4 decreasing slightly in length apically, each with usually 4 short dark spine-like apicoventral setae; tarsomere 5 subequal in length to tarsomere 3, apex lacking medial finger-like process. Hindleg: Coxa with 3–4 setulae on outer surface; femur slightly longer than tibia; tibia slender; tarsus slightly shorter than tibia; tarsomere 1 subequal to combined length of tarsomeres 2–5, with spinose posteroventral tubercle at base; tarsomeres 2–4 decreasing slightly in length apically; tarsomere 5 subequal in length to tarsomere 3, apex lacking medial fingerlike process. Wing ( Figs. 3A, 3B): Hyaline, veins dark brown, about 2.5X longer than wide. Pterostigma indistinct, membrane entirely covered with minute microtrichia, alula absent. Costa circumambient. Extreme anterior base of costa with 2 anterodorsal setae. Anterior section of costa (between base and R4+5) bearing double row of spine-like setae, setae of ventral row stronger. Posterior section of costa (i.e. beyond R4+5) with setae finer and longer. Costal section proximal to apex of R1 with setae larger, spine-like and more widely spaced. Longitudinal veins complete, reaching wing margin, except anal vein (CuP+CuA) absent, Sc faint apically. R1 reaching costa beyond middle of wing (or beyond base of M2). Base of Rs originating opposite humeral crossvein. R2+3 more or less straight. Cell r2+3 narrowing before apex where R4+5 curves forward, broadening to apex (veins R2+3 and R4+5 divergent). R4+5 and M1 sinuous, curving forward then backward, diverging apically. M2 and M4 nearly straight and subparallel beyond cell dm. Costal section between M1 and M2 distinctly longer than costal section between M2 and M4. CuA rounded. Short r-m crossvein present in basal portion of wing, distal to base of R4+5. Crossvein bm-m incomplete. Cell dm present with veins M2 and dm-m, cell extending to middle of wing, base of M2 sometimes faint to indiscernible from wing membrane. Cells br, bm and cua in basal fourth of wing. Cells bm and cua broader than br. Cell cua closed, ovoid. Anal lobe not developed. Calypter with fine pale setae. Abdomen ( Figs. 1 View FIGURE 1 A, 5 View FIGURE 5 ): Abdominal muscle plaques present. Tergite 1 with scattered setae; tergites 2–6 with scattered posteromarginal setae, setae stronger laterally on tergites 2–4; sternites 2–4 setose; sternite 4 emarginate medially, right and left side with series of long posteromarginal setae; sternite 5 with projecting pregenitalic process, apex of process expanded and weakly emarginate, base of process with pair of short projections posteriorly, sternite with 2–3 setulae laterad process otherwise bare; sternite 6 sometimes with pair of close-set setulae per side, otherwise bare; segment 7 bare. Segments 1–4 mostly symmetrical with simple tergites and sternites; segments 5–7 narrowed, somewhat more heavily sclerotized (especially segments 6 and 7) and laterally compressed to form cavity on right side for hypopygium. Sternite 6 strongly produced ventrally. Sternite 7 simple, not contorted, lacking pregenitalic process. Sternite 8 slightly wider than long, subrectangular, setose; tergite 8 forming narrow sclerotized U-shaped band, laterally fused to posterior margin of sternite 8. Hypopygium ( Figs. 5 View FIGURE 5 , 6 View FIGURE 6 ): Lateroflexed to right; inverted with posterior end directed anteriorly; large and globular, about 1/2 length of abdomen; asymmetrical. Epandrium divided into left and right lamellae. Left epandrial lamella ( Fig. 6 View FIGURE 6 A) narrowly constricted at middle with broad dorsal and ventral portions, ventral epandrial portion partially overlapping left side of hypandrium and fused to hypandrium along lower edge but epandrial margin distinct; ventral epandrial process ( Fig. 6 View FIGURE 6 A) basally articulated, Y-shaped with apical half broadly furcate, dorsal arm narrow, curved and tapering apically, ventral arm thick with ventral setula near midlength and lacking hump-like projection at base. Left surstylus ( Figs. 6 View FIGURE 6 A, 6C) complex, dorsal and ventral lobes separated by shallow U-shaped cleft through which left postgonite lobe protrudes. Dorsal lobe of left surstylus ( Fig. 6 View FIGURE 6 A) with thumb-like outer lobe bearing stout apical seta, and slender medial lobe with shallowly furcate apex. Ventral lobe of left surstylus broad in lateral view ( Fig. 6 View FIGURE 6 A), with complex multilobate medial projection ( Fig. 6 View FIGURE 6 C). Right epandrial lamella ( Figs. 5 View FIGURE 5 B, 6D) partially overlapping right side of hypandrium, not fused with hypandrium; apical portion of epandrial lamella broad with, rounded apicoventral projection below ventral surstylus; basal portion of epandrial lamella with deep dorsal emargination bordering ventral margin of right cercus. Right surstylus ( Fig. 6 View FIGURE 6 D) with dorsal and ventral lobes separated by deep cleft through which right postgonite lobe protrudes. Dorsal lobe of right surstylus ( Fig. 6 View FIGURE 6 D) with subtriangular outer lobe bearing apical seta, and slender club-like medial lobe with expanded apex. Ventral lobe of right surstylus broad with tapered base, with narrow dorsoapical process and 2 strong hook-like setae along ventroapical margin. Hypandrium ( Figs. 5 View FIGURE 5 A, 5B, 6A, 6E) large, reniform, posterior end deeply notched with associated longitudinal furrow forming shallow cavity for phallus, with 2 short dentiform projections left of notch. Postgonite with basal internal portion cradling base of phallus ( Figs. 6 View FIGURE 6 A, 6E), left side with broad anterolateral apodeme; left and right postgonite lobes protruding out from between dorsal and ventral lobes of surstylus. Left postgonite lobe ( Fig. 6 View FIGURE 6 A) with basal portion slender and curved, apical portion broad with complex cuticular projections medially, apex bifurcate. Right postgonite lobe ( Fig. 6 View FIGURE 6 E) broad basally, apical half narrower with fine pointed apical process. Phallus elongate, J-shaped ( Figs. 6 View FIGURE 6 A, 6E), left side with pointed process near middle and second smaller pointed process preapically. Ejaculatory apodeme ( Figs. 6 View FIGURE 6 A, 6E) laterally flattened, keel-like, with broad apex. Hypoproct ( Figs. 6 View FIGURE 6 A, 6B) projected as pair of upturned slender asymmetrical non-setose lobes. Cerci ( Figs. 5 View FIGURE 5 C, 6B, 6E) asymmetrical, basilateral portion of right cercus enlarged and rounded; right and left cercus each with elongate apicolateral projection, apicomedial tubercle bearing 2 bristles (tubercle longer on left), and row of 3 setae along medial margin.

Female: Body length 1.7–1.9 mm, wing length 1.4–1.8 mm. Similar to male except as follows: Head ( Fig. 2 View FIGURE 2 B): Face about 2.3–2.8X width of anterior ocellus; antenna with stylus subequal to 2/3 length of postpedicel. Thorax: Notopleuron sometimes with additional weaker setae in addition to 2 strong notopleural bristles. Legs: Foreleg: Femur without row of erect posteroventral setae; tibia without posterior and ventral rows of erect setae. Midleg: Femur without row of long erect posteroventral setae; tarsomere 1 not bowed, without ventral comb-like row of hook-like setae, without strong basiventral setae. Wing ( Fig. 3C): Costal setae proximal to apex of R1 not enlarged and widely spaced. R4+5 and M1 with curvature less pronounced. Abdomen: Tapering posteriorly, apical segments partially retracted into segment 5; tergite and sternite 6 with row of well-developed posteromarginal setae. Terminalia ( Fig. 7 View FIGURE 7 ) with tergite 7 complete, narrow medially; sternite 7 complete; tergite 8 complete, not divided medially, anterior margin darkened and emarginate ( Fig. 7 View FIGURE 7 B), not fused with sternite 8 anterolaterally ( Fig. 7 View FIGURE 7 A); sternite 8 complete, narrowing apically to short bifurcate tip ( Fig. 7 View FIGURE 7 C); tergite 10 medially divided, with 2 long acanthophorite setae on each side ( Fig. 7 View FIGURE 7 B); sternite 10 medially divided into a pair of narrow elongate bands ( Fig. 7 View FIGURE 7 C); cercus short, rounded and fleshy, outer surface with several long setae; spermatheca an unsclerotized unpigmented tube with sperm pump at base ( Fig. 7 View FIGURE 7 B).

Distribution. Microphorella similis is currently known only from the type locality at Leuk-Pfynwald, Switzerland.

Comparison with Microphorella praecox . Microphorella similis most closely resembles M. praecox , the type species. It shares with M. praecox the following externally discernible characters: antenna ( Figs. 1 View FIGURE 1 B, 1C, 4A; see also Chvála 1988, fig. 4) with postpedicel elongate, roughly conical, with broad basal portion and narrow distal portion, stylus claw-shaped (i.e., evenly tapered from base to pointed tip and gently curved ventrad), distinctly shorter than postpedicel in male, at most subequal in female, female terminalia ( Fig. 7 View FIGURE 7 ) with sternite 8 narrow and bifurcate apically.

Microphorella similis differs from M. praecox as follows: postpedicel shorter and stylus longer ( Fig. 1 View FIGURE 1 B) (postpedicel longer and stylus shorter in M. praecox , Fig. 1 View FIGURE 1 C), R4+5 and M1 sinuous ( Figs. 3A, 3C) (straight in M. praecox , Figs. 3D, 3F), ventral epandrial process lacking hump-like projection on ventral arm of furca ( Figs. 6 View FIGURE 6 A) (projection present in M. praecox ; Fig. 8 View FIGURE 8 A), left postgonite lobe with bifurcate apex ( Figs. 6 View FIGURE 6 A) (pointed in M. praecox , Fig. 8 View FIGURE 8 A), phallus bearing pointed process near middle and lacking longitudinal serration ( Figs. 6 View FIGURE 6 A, 6E) (process absent and serration present in M. praecox , Figs. 8 View FIGURE 8 A, 8C), right cercus with basilateral portion enlarged ( Fig. 6 View FIGURE 6 B) (less developed in M. praecox , Fig. 8 View FIGURE 8 B).

Remarks. The type series of M. similis was collected (along with specimens of M. praecox ) by sweeping above gravel in the floodplain of the Rhône River during mid May. Besides the type series detailed above, additional specimens of M. similis from the same two collecting events at Leuk-Pfynwald, are deposited in the ZFMK and MHNG.

Etymology. The specific epithet is derived from the Latin similis (=similar) referring to the similarity of this species to Microphorella praecox (Loew) , the type species of Microphorella .