Microphorella trochanterata, 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 : 489-492

Microphorella trochanterata sp. nov.

urn:lsid:zoobank.org:act:A9F90F27-7385-49A3-885E-C1D7542873B7

( Figs 92–99 , 105 )

Type material. HOLOTYPE, ♂ ( Fig. 92 ) labelled: “USA: CALIFORNIA: Mon-| terey County, Carmel | Valley , HastingsNatural | History Reservation | ca 1750' 19-Jun-1998 ”; “Paul H. Arnaud, Jr.| & Madeline M. Arnaud | Arnaud Flight Trap | over Big Creek | Collection No. 01958-A”; “ HOLOTYPE | Microphorella | trochanterata | Brooks & Cumming” [red label] ( USNM) . PARATYPES: USA: California: Marin County: Cypress Ridge, vic. Alpine Lake [37°56'N 122°38'W], 22.v.1967, P.H. Arnaud, Jr, CNC 1155849 (1♂, USNM). Monterey County: same data as holotype [36°22'N 121°33'W] (1♂, USNM) .

Diagnosis. In addition to the characters listed above for the M. trochanterata lineage, males of this species can easily be distinguished from other members of the M. acroptera species group by the distinctive tubercle of the hind trochanter ( Figs 93, 94 ), the row of long setae on the hind tibia ( Fig. 93 ), the elongate setae on abdominal sternite 8 ( Figs 92, 96 ) and the knob-like posterior protrusion of the hypandrium ( Figs 97, 98 ).

Description. Male ( Figs 92–99 ): Wing length 1.2–1.3 mm. Head ( Fig. 92 ): Mainly blackish-brown pruinose, ventral part of frons, face and clypeus blackish-brown in anterior view; about as wide as thorax in dorsal view; ovoid in lateral view (higher than broad); slightly broader than high in anterior view; larger setae black, smaller setae brown. Ocellar triangle conspicuous. Occiput weakly concave on upper median part. Eyes covered with short ommatrichia; medial edge of eye with small emargination adjacent to antenna; ommatidia slightly larger in size ventrally. Frons about 2× broader than high, widening above. Face slightly tapered ventrally to about width of anterior ocellus. Face and clypeus blackish-brown with brownish-grey pruinosity, concolourous with ventral part of frons (in anterior view). Clypeus separated from face, small, slightly narrower than high, with truncate ventral margin. Setae of head well differentiated (larger dorsal setae similar in size to anterior dorsocentrals): 1 pair of inclinate fronto-orbitals arising slightly ventral to median ocellus; 1 pair of lateroclinate anterior ocellars; 1 pair of small posterior ocellars; 1 pair of inner verticals (sometimes referred to as postocellars); 2 pairs of outer verticals; postocular setae short and uniserial.Antenna inserted above middle of head in profile; scape short, funnel-shaped, dark brown; pedicel about 2× longer than scape, spheroidal with subapical circlet of setulae, dark brown; postpedicel about 2× longer than pedicel, about 2× longer than wide, bulb-shaped, blackish-brown, clothed in fine setulae; arista-like stylus apical, 2× length of postpedicel, blackish-brown, with minute hairs. Palpus dark brown, relatively small, narrowly ovate, about 2.5× longer than wide, with 1 long preapical seta. Proboscis brown, short, projecting ventrally. Gena narrow. Thorax ( Fig. 92 ): Blackish to blackish brown and shiny, dorsum with weak bronze pruinosity, setae black. Mesoscutum moderately arched, prescutellar depression present. Proepisternum with 2 tiny setae. Postpronotal lobe with a few small setae. Mesonotum longer than wide. Acrostichal setae short, biserial, extending to prescutellar depression; setae on each side of mesonotum: 7–8 dorsocentrals, most short with posterior setae longer, 1 presutural supra-alar (posthumeral), 2–3 small postsutural supra-alars, 2 notopleurals, 1 postalar, area laterad dorsocentrals with a few small setae. Scutellum broadly crescent-shaped with 1 long seta and 1–2 small outer setae per side. Mesopleuron bare. Halter blackish brown. Legs: Slender; dark brown with prominent setae black; femora, tibiae and tarsi largely covered with tiny, black 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 setae on anterior surface, stronger and longer apically; femur, tibia and tarsus subequal in length; tarsomere 1 subequal to combined length of tarsomeres 2–4. Midleg: Coxa with a few prominent setae on anterior surface; femur slightly shorter than tibia, tibia subequal in length to tarsus; apex of tibia with 1 strong ventral seta; tarsomere 1 subequal to combined length of tarsomeres 2–4, with a few erect basiventral setae and longitudinal row of short setae. Hindleg: Coxa with 2 prominent setae on lateral surface; trochanter ventrally with large complex tubercle ( Figs 93, 94 ), tubercle with cylindrical stem-like base and broad oval, disc-like apex bearing a large, anteroventrally directed, spine-like seta with pointed tip, stem-like base with subapical tuberculate ventral seta, disc-like apex with margin of anterior surface ( Fig. 94 ) and posterior surface ( Fig. 93 ) desclerotized, posterior surface concave; femur, tibia and tarsus subequal in length; femur strongly bowed outwardly (in dorsal view), with prominent anteroventral row of setae, setae subequal to femur width; tibia with dorsal row of about 5 long setae, shortening distally, proximal seta nearly as long as tibia; tarsomere 1 subequal to combined length of tarsomeres 2–4, with thick, stubby, spur-like basiventral seta borne on mound-like tubercle. Wing ( Figs 92, 95 ): Relatively small, slightly shorter than body, R 1 ending at level of M 2, otherwise as in description of M. acroptera . Abdomen ( Figs 92, 96 ): Blackish with short dark setae (very weak on sternites); segment 7 bare. Segments 5–7 narrowed and laterally compressed to form cavity on right side for hypopygium. Sternite 5 with broad bilobate ventral projection, symmetrical with short rounded lateral lobes. Sternite 6 with narrow process, with stalk-like base and flared apex ( Fig. 96 ). Sternite 8 rounded and slightly wider than segment 7, setose on and adjacent to margin, with 4 elongate setae on posterior margin, outer pair longer than sternite 8 and about 3× longer than inner pair; tergite 8 vestigial. Hypopygium ( Figs 96–99 ): Concolourous with abdomen; lateroflexed to right; inverted with posterior end directed anteriorly; large, nearly as long as abdomen; asymmetrical. Right and left epandrial lamellae narrowly connected dorsally behind cerci. Left epandrial lamella ( Fig. 98 ) shorter than hypandrium and mostly overlapping its left side, posterior margin with projecting surstylar lobes and ventral epandrial process, ventral edge broadly rounded and fused with hypandrium but margin distinct; ventral epandrial process articulated at base, basal 2/3 of uniform width, apex widely bifurcate. Left surstylus divided into dorsal and ventral lobes separated by cleft adjacent to left postgonite lobe. Dorsal lobe of left surstylus long and broad with prominent lateral ridge, with deeply cleft apicodorsal process bearing basal prensiseta and broadly rounded flap-like medioventral process. Ventral lobe of left surstylus narrow, digitiform, shorter than dorsal lobe of surstylus, with a few apical setae. Right epandrial lamella ( Fig. 97 ) shorter than hypandrium and partially overlapping its right side, longer than high, ventral edge sinuously curved and fused with hypandrium, margin mostly distinct, fading into hypandrium anterodorsally; ventral epandrial process absent. Right surstylus divided into dorsal and ventral lobes separated by V-shaped cleft through which right postgonite lobe protrudes. Dorsal lobe of right surstylus narrow with preapical prensiseta subtended by pair of small setae, apex projecting medially with small apical seta. Ventral lobe of right surstylus longer and broader than dorsal lobe of surstylus, with narrowed tip. Hypandrium ( Figs 97, 98 ) large and ovoid, with knob-like posterior protrusion. Left postgonite lobe long and broad with trifurcate apex ( Fig. 98 ), dorsal process about half as long as middle process, ventral process projecting medially and about 1.5× longer than middle process. Right postgonite lobe narrow with bifurcate apex ( Fig. 97 ), as long as ventral lobe of surstylus. Phallus J-shaped, with elbow-like articulation point near mid-length, apex bifurcate with narrow curved process nearly as long as straight tubular distal portion of phallus. Ejaculatory apodeme large, keel-like, with pointed posterior margin and rounded anterior margin. Hypoproct simple, left and right lobes symmetrical, subrectangular and flap-like with a few tiny setae. Cercus ( Fig. 99 ) long and digitiform, curved medially with several long lateral setae and 1 shorter medial seta, base of cercus membranous laterally, left and right cercus symmetrical.

Female. Unknown.

Distribution and seasonal occurrence. This new species is known from specimens collected in May and June in the San Francisco Bay Area and Monterey County of northern and central California ( Fig. 105 ).

Etymology. This species is named for the unusual morphology of the trochanter of the male hindleg ( Figs 93, 94 ).

Figures

FIGURES 92–96. Male habitus, hindleg, wing and abdomen of Microphorella trochanterata sp. nov. 92. Habitus of holotype, arrow indicates setae of sternite 8. 93. Left hindleg of holotype, posterior view. 94. Same, anterior view. 95. Wing of paratype (Carmel Valley, California). 96. Abdomen of holotype, arrow indicates process of sternite 6. Abbreviations: bm-m—basal medial crossvein; cua—anterior cubital (=anal) cell; CuA—anterior branch of cubital vein; CuA+CuP—anterior branch of cubital vein + posterior branch of cubital vein; dm—discal medial cell; h—humeral crossvein; M1, M2, M4—medial veins; R1, R2+3, R4+5—radial veins; Sc—subcostal vein.

FIGURES 97–99. Hypopygium of Microphorella trochanterata sp. nov. (CNC1155849). 97. Hypopygium, right lateral view. 98. Same, left lateral view. 99. Cerci, dorsal view. Abbreviations: cerc—cercus; d sur—dorsal lobe of surstylus; epand— epandrium; hypd—hypandrium; pgt lb—postgonite lobe; ph—phallus; v epand proc—ventral epandrial process; v sur—ventral lobe of surstylus.

FIGURES 104–105. Known geographical distribution of the Microphorella acroptera species group. 104. Microphorella serpentina sp. nov., M. elongata sp. nov. and M. tenuis sp. nov. 105. Microphorella maculata sp. nov., M. trochanterata sp. nov. and Microphorella sp. A.