Microphorella sinuosa, Brooks & Cumming, 2025

Brooks, Scott E. & Cumming, Jeffrey M., 2025, Revision of the Microphorella acroptera species group and establishment of the Microphorella arcana species group (Diptera: Dolichopodidae sensu lato: Parathalassiinae), Zootaxa 5661 (4), pp. 451-503 : 470-471

Microphorella sinuosa sp. nov.

urn:lsid:zoobank.org:act:BB526468-87E3-47EC-9532-A798162EB0C4

( Figs 47–55 , 102 )

Type material. HOLOTYPE, ♂ ( Fig. 47 ) labelled: “ Malaise Trap | Lily Pond [37°56'N 122°38'W], 1500'[ft.]| Alpine Lk., Marin| Co., Cal. 6| VII.70”; “ HOLOTYPE | Microphorella | sinuosa | Brooks & Cumming” [red label] ( UCDC). See Remarks . PARATYPES: USA: California: Contra Costa County: Briones Reg. Park at Alhambra Valley Rd [37°57'N 122°08'W], 20.iii.1978, D.D. Wilder (1♂, CAS). Mendocino County : Hopland Field Station [39°00'N 123°04'W], Kelsey Cab. Orch. Area , 2600–2800 ft., 1.v.1982, N. Stone, EMEC 1188818 (1♂, EMEC). Monterey County : Horse Bridge, 1.5 air mi. SW Arroyo Seco Grd Sta. [36°14'N 121°28'W], 3–8.v.1975, E. Rogers, EMEC 1188815 (1♂, EMEC); same data except, EMEC 1188491 , CNC1155836 (1♂, EMEC). Sacramento County : Elk Grove [38°24'N 121°22'W], 18.iv.1952, E.C. Carleson (4♂, 6♀, UCDC); same data except, CNC1155829 , CNC1155830 (2♂, UCDC). Santa Barbara County : Los Prietos [34.5416°N 119.8020°W], 14.iii.1967, Ceanothus, J. Powell, EMEC 1189165, CNC1155835 (1♂, EMEC). Santa Clara County : creek along Sanborn Rd, 2.7 km SE Congress Springs Rd [37°13'N 122°03'W], ca. 440 m, 14.iv.1974, P.H. Arnaud, Jr (1♂, USNM) .

Diagnosis. Males of this species can be distinguished from other members of the M. acroptera species group by the following combination of characters: acrostichal setae well-developed, biserial; hind basitarsus without basiventral spur-like seta; halter dark brown ( Fig. 51 ); hind trochanter with cylindrical tubercle; face with sides subparallel; hypandrium large and bulbous ( Figs 52, 53 ); dorsal lobe of surstylus with pair of prensisetae (1 disc-like, 1 blade-like, Figs 52, 53 ); cercus with digitiform lateral lobe ( Fig. 55 ).

Description. Male ( Figs 47–55 ): Wing length 2.4–2.8 mm. Similar to M. acroptera except as follows: Head ( Fig. 47 ): Face and clypeus slightly broader, about 2.25× width of anterior ocellus. Thorax: Acrostichals biserial, with well-developed rows extending to prescutellar depression; 7–8 dorsocentrals; area laterad dorsocentrals usually more extensively covered with small setae. Legs: Hindleg: Trochanter tubercle with spine-like seta shorter with sharply pointed tip ( Figs 48, 51 ). Wing: As in description of M. acroptera . Abdomen ( Figs 49–51 ): Sternite 5 with broad ventral bilobate projection ( Figs 49–51 ), with elongate, digitiform, spiny lateral lobes. Hypopygium ( Figs 49, 51–55 ): Left epandrial lamella ( Fig. 52 ) slightly shorter than hypandrium; ventral epandrial process with bifurcate apex and pair of small setae borne on tubercles, bifurcation variable, with processes similar in size and adjacent to each other ( Fig. 54 ), or of different sizes and divergent ( Figs 51 , 52 ). Dorsal lobe of left surstylus with broad, truncate dorsolateral lobe bearing 2 prominent prensisetae (upper one disc-like, lower one blade-like) and 1 long posterior seta; medioventrally with tubercle bearing sinuous seta and broad adjacent lobe. Ventral lobe of left surstylus slightly longer than dorsal lobe, with shallowly bilobate apex (best seen in posterior view), outer lobe bearing 2 setae, inner lobe bearing 3 setae (one of which is branched apically). Right epandrial lamella ( Fig. 53 ) with ventral margin mostly distinct, fading into hypandrium anteriorly. Dorsal lobe of right surstylus broad and truncate (similar to left side), bearing 2 prominent prensisetae (upper one disc-like, lower one blade-like), 1 lateral setae posterior to ventral prensiseta and 1 seta medially. Ventral lobe of right surstylus as long as dorsal lobe, medially curved at base with apex projecting dorsally and expanded, with several setae on posterior surface. Phallus ( Figs 52, 53 ) long and convoluted, basal portion tubular with S-shaped double curve, followed by inflated and protruding apical portion which gradually tapers to tip, with small dentiform process near base of inflated portion and second process preapically. Cercus ( Figs 52, 53, 55 ) with digitiform lateral lobe projecting dorsally from cercal base.

Female. Similar to male except as follows: Head: Face and clypeus apparently slightly broader, broader than 2.5× width of anterior ocellus. Legs: Hindleg: Trochanter without tubercle bearing apical spine-like seta; femur without prominent anteroventral row of setae. Abdomen: As in description of M. acroptera .

Distribution and seasonal occurrence. This new Californian species is known from southern Mendocino County south to Monterey County and east to Sacramento County ( Fig. 102 ). Specimens were collected from March to July.

Etymology. This species is named for the sinuous basal part of the phallus, a characteristic feature of the M. acroptera lineage.

Remarks. This species appears to be closely related to M. bifida sp. nov., with which it shares very similar hypopygial morphology, especially in the structure of the dorsal surstylar lobes, phallus and cercus ( Figs 25–28 , 52–55 ).

The holotype ( Fig. 47 ) is a well-preserved critical point dried specimen in excellent condition, but lighter in colouration than the paratypes, presumably as a result of storage in ethanol for some time prior to drying.

Figures

FIGURES 47–51. Male habitus, hindleg and abdomen of Microphorella sinuosa sp. nov. 47. Habitus of holotype. 48. Legs of holotype, left lateral view, arrow indicates trochanter tubercle. 49. Abdomen of holotype, dorsal view, arrow indicates process of sternite 5. 50. Process of sternite 5 (CNC1155835), posterior view. 51. Abdomen and right hindleg of paratype (Elk Grove, California), lateral view, arrows indicate trochanter tubercle and process of sternite 5.

FIGURES 52–55. Hypopygium of Microphorella sinuosa sp. nov. 52. Hypopygium (CNC1155830), left lateral view. 53. Same, right lateral view. 54. Tip of ventral epandrial process (CNC1155835, CNC1155836), left lateral view. 55. Cerci (CNC1155836), dorsal view. Abbreviations: cerc—cercus; d sur—dorsal lobe of surstylus; hypd—hypandrium; pgt lb—postgonite lobe; ph— phallus; v epand proc—ventral epandrial process; v sur—ventral lobe of surstylus.

FIGURES 102–103. Known geographical distribution of the Microphorella acroptera species group. 102. Microphorella paracroptera sp. nov., M. sinuosa sp. nov. and M. subacroptera sp. nov. 103. Microphorella acuminata sp. nov., M. compacta sp. nov. and M. cornuta sp. nov.

FIGURES 25–28. Hypopygium of Microphorella bifida sp. nov. 25. Hypopygium (CNC1155831), left lateral view. 26. Same (CNC1155824), right lateral view. 27. Phallus (CNC1155824), ventral view. 28. Cerci (CNC1155831), dorsal view. Abbreviations: cerc—cercus; d sur—dorsal lobe of surstylus; hypd—hypandrium; ph—phallus; v epand proc—ventral epandrial process; v sur—ventral lobe of surstylus.