Microphorella tubifera Melander

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 : 474-478

Microphorella tubifera Melander

( Figs 60–70 , 101 )

Microphorella tubifera Melander, 1928: 88 .

Microphorella tuberifera, Melander (1928: 88 , key), misspelling.

Type material. HOLOTYPE, ♂ ( Figs 60–62 ) labelled: “Palo Alto, Cal.| 2 Mar. ’95”; “ R. W. Doane | Collector”; “ TYPE | Microphorella | tubifera| Mel.” [red label]; “ALMelander| Collection| 1961” ( USNM) . PARATYPE: USA: California: Santa Clara County: same data as holotype [37°25'45"N 122°8'17"W] except, 26.iii.1985 (1♀, USNM) .

Other material examined. USA: California: Marin County: Liberty Gulch nr Alpine Lake [37°57'N 122°37'W], 640–900 ft, 16.iv.1971, P. Loggins, Univ. Calif. Insect Survey Specimen # 100068, EMEC 1188832 (1♀, EMEC) . Mendocino County: NCCRP 3 mi. N Branscomb [39°42'N 123°39'W], 1400 ft, 17.v.1975, J. Powell, Univ. Calif. Insect Survey Specimen #’s 181899–181905, EMEC 1188490 , 1188503–1188505 , 1188506 , 1188833 (2♂, 4♀, EMEC) ; same data except, Univ. Calif. Insect Survey Specimen # 181907, EMEC 1188505 , CNC1155805 (1♂, EMEC) . San Mateo County: Junipero Serra Park [37.609°N 122.426°W], 4.iv.1964, P.H. Arnaud, Jr (1♂, CAS); Redwood City [37°28'58"N 122°14'10"W], 28.ii.1943, P.H. Arnaud coll. (1♂, 1♀, mounted as pair, USNM) .

Diagnosis. Males of this distinctive species can be easily distinguished from other members of the M. acroptera species group by the large clavate tubercle on the hind trochanter ( Fig. 66 ) and the unusual hypopygium ( Figs 61 , 66–69 ) with projecting posterior components pale yellow and large bicoloured cercus with pale yellow base and dark brown subtriangular apical lobe. Males and females are further distinguished by their relatively large, stocky body, ventrally tapering face and brown-tinged wing.

Description. Male ( Figs 60–70 ): Wing length 2.0–2.3 mm. Similar to M. acroptera except as follows: Body relatively large and stocky. Head ( Figs 63–65 ): Face tapered ventrally to width of anterior ocellus; antenna with arista-like stylus longer, nearly 2.5× length of postpedicel. Thorax ( Figs 60, 63–66 ): Coppery brown pruinose to blackish-bronze pruinose; acrostichals biserial, with well-developed rows almost extending to prescutellar depression; 5–6 prominent dorsocentrals; scutellum usually with small outer seta laterad long seta. Legs: Foreleg: Femur thicker, with row of fine posteroventral setae, setae shorter than femur width. Hindleg: Trochanter ( Fig. 66 ) with tubercle large and clavate, bearing thick, blunt-tipped spine-like seta; tibia with longer erect setae ventrobasally; basitarsus with longitudinal series of 4 tiny, upturned spur-like setae basiventrally. Wing: Membrane with brownish tinge, otherwise as in description of M. acroptera . Abdomen ( Figs 61 , 66 ): Sternite 5 with broad, trilobate, strongly protruding ventral projection ( Figs 66 , 70 ), membranous posteromedially, with broad conical medial lobe and hook-like lateral lobes. Sternite 8 oval with tapered base. Hypopygium ( Figs 61 , 66–69 ): Mostly concolourous with abdomen, base of cerci and other projecting posterior components pale yellow. Left epandrial lamella ( Fig. 67 ) as long as hypandrium; ventral epandrial process unusual in shape, broad with dorsal margin rounded and finely serrate, apically with narrow pointed projection adjacent to broad rounded lobe with pair of apical setae. Dorsal lobe of left surstylus broad and truncate with short marginal seta, medial surface bearing elongate prensiseta with 90° preapical bend and adjacent unmodified seta. Ventral lobe of left surstylus longer than dorsal surstylar lobe, clavate with 3 long, thick apical setae and 2 smaller setae. Right epandrial lamella ( Fig. 68 ) as long as hypandrium. Dorsal lobe of right surstylus lacking prensiseta, with boot-shaped lobe bearing 3 lateral setae, subtended by weakly sclerotized, pillow-like lobe anteriorly. Ventral lobe of right surstylus about twice as long as dorsal surstylar lobe, clavate with apex setulose and bearing a few setae. Hypandrium ( Figs 67, 68 ) relatively small, as long as epandrium in lateral view. Left postgonite lobe globular basally with bifid apex projected medially (best seen in dorsal view), inner lobe thumb-like, outer lobe elongate and tapered to bluntly pointed tip ( Fig. 67 ). Right postgonite ( Fig. 68 ) smaller with inner and outer lobes similar in length. Phallus ( Figs 67, 68 ) long and convoluted, basal portion tubular with S-shaped double curve followed by large, inflated portion which tapers to tip. Ejaculatory apodeme small, keel-like. Hypoproct lobes globular. Cercus ( Figs 67–69 ) large and distinctive, basally pale and setulose, with short, rounded, dorsolaterally projecting ridge and dark, subtriangular medial lobe bearing long seta on outer surface and several smaller setae.

Female. Similar to male except as follows: Head: Antenna with arista-like stylus shorter, about 2× length of postpedicel. Legs: Foreleg: Femur without row of fine posteroventral setae. Hindleg: Trochanter without tubercle bearing apical spine-like seta; femur without prominent anteroventral row of setae; tibia with setae unmodified; basitarsus without basiventral spur-like setae. Abdomen: As in description of M. acroptera .

Distribution and seasonal occurrence. The few known specimens of this species were collected from February to May in the San Francisco Bay Area and northern Mendocino County, California ( Fig. 101 ).

Figures

FIGURES 60–63. Microphorella tubifera Melander, male holotype and male from Redwood City, California. 60. Habitus of holotype. 61. Abdomen of holotype, left lateral view. 62. Labels of holotype. 63. Head and thorax of male from Redwood City, California, anterolateral view.

FIGURES 64–66. Habitus, thorax, abdomen and hindleg of Microphorella tubifera Melander male from Redwood City, California. 64. Habitus, left lateral view. 65. Habitus, right lateral view. 66. Thorax, abdomen and hindleg, right lateral view, arrows indicate trochanter tubercle and process of sternite 5.

FIGURES 67–70. Male terminalia of Microphorella tubifera Melander (CNC1155805). 67. Hypopygium, left lateral view. 68. Same, right lateral view. 69. Cerci, dorsal view. 70. Sternite 5, posteroventral 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 100–101. Known geographical distribution of the Microphorella acroptera species group. 100. Microphorella acroptera Melander and M. convoluta sp. nov. 101. Microphorella bifida sp. nov., M. triangulata sp. nov. and M. tubifera Melander.