Roederiodes wirthi Chillcott

Sinclair, Bradley J., 2023, Revision of New World species of Roederiodes Coquillett (Diptera: Empididae: Clinocerinae), Zootaxa 5301 (3), pp. 336-364 : 359-360

Roederiodes wirthi Chillcott

( Figs 10 , 29 , 34 )

Roederioides wirthi Chillcott, 1961: 426 . Type locality: Glenwood , New Mexico, USA.

Roederiodes wirthi: Melander, 1965: 468 [catalogue]; Wilder, 1981: 420 [review]; Sinclair, 1995: 698 [species list].

Roederioides retroversa Chillcott, 1961: 427 . Type locality: St. Helena Creek [38°44′N 122°37′W], Lake Co., California, USA .

Roederiodes retroversa: Wilder, 1981: 420 [as synonym of wirthi ]; Sinclair, 1995: 698 [as synonym of wirthi ].

Roederiodes retroversus: Melander, 1965: 468 [catalogue].

Type material. Roederiodes retroversus : HOLOTYPE ♁, labelled: “ St. Helena Creek / Lake Co. [ca. 38.653°N 122.597°W] Cal./17.III.48.”; “ W.W. Wirth / Collector”; “Stream/ margin”; “HOLOTYPE/ Roederioides / retroversa/ No. Chillcott / 65093 [red label]” [dissected] ( USNM).

Roederiodes wirthi : HOLOTYPE ♁, labelled: “ NEW MEXICO / CatronCo 5/ miEGlenwood/ 24June1953 ”; “WW Wirth/ Collector”; “ HOLOTYPE / Roederioides / wirthi/ No. Chillcott/ 65092. [red label]” ( USNM). PARATYPES: Same data as holotype (2 ♁ [= chillcotti sp. nov.], 1 ♁, CNC; 1 ♁ [= chillcotti sp. nov.], 4 ♁, USNM). The female type series (3 ♀, CNC; 6 ♀ (incl. allotype), USNM) are indistinguishable from females of R. chillcotti sp. nov.

Notes on types. Roederiodes retroversus was described based on the male holotype, which was dissected and the male terminalia illustrated ( Chillcott 1961, fig. 20). Roederiodes wirthi was based on a holotype, allotype and 18 paratypes. The holotype, allotype and 15 paratypes were examined and found to comprise a mixture of two species. Chillcott (1961, fig. 19) dissected and illustrated one of three male paratypes of R. wirthi that were retained in the CNC. The illustrated male paratype is clearly not conspecific with the holotype of R. wirthi and distinctly different from the illustration of the male terminalia of R. retroversus . Wilder (1981) did not identify the mixed series, but discovered that the holotypes of R. wirthi and R. retroversus were conspecific, both types matching the male terminalia of R. retroversus illustrated by Chillcott (1961, fig. 20), leading her to propose R. retroversus as a junior synonym of R. wirthi . Consequently, the species illustrated by Chillcott (1961, fig. 19) as “ R. wirthi ” represents an undescribed species (see R. chillcotti sp. nov.).

Additional material examined. USA. Arizona: Coconino Co., Oak Ck Canyon, Cave Springs Cpgd [34.996°N 111.739°W], 4500 ft, 21–23.v.1971, PHA & M. Arnaud (2 ♁, USNM) . California: Same data as holotype (2 ♁, 1 ♀, USNM); Alameda Co., Sunol [37°35′N 121°53′W], 3.iv.1939, T. G.H. Aitken (2 ♀, CAS); same data except, Calaveras Ck, 18.x1938 (1 ♁, 1 ♀, CAS); Calaveras Co., West Point , Hwy 26 [38.389°N 120.526°W], Middle Fk Mokelumne R, 5.x. 1985, 730 m, PHA (1 ♁, 3 ♀, USNM) ; Contra Costa Co., Las Trampas Regional Wilderness [37.82°N 122.05°W], 4.iv.1978, DDW (2 ♁, 3 ♀, CAS) ; El Dorado Co. , Riverton, South Fk American R, 983 m, 38°46′15.2″N 120°26′53.45″W, 31.v.2009, BJS (1 ♀, CNC) ; Fresno Co., Kings R., Garnet [36.869°N 119.030°W], 20.v.1985, JFM (1 ♁, CNC); Los Angeles Co., W Fk San Gabriel R, along Hwy 39 [34.241°N 117.868°W], 2 mi. S Coldbrook Stn, 25.iv.1977, DDW (62 ♁, 72 ♀, CAS; 1 ♁, USNM); same data except, 6–7.iv.1977 (57 ♁, 74 ♀, CAS, 1 ♀, USNM); Monterey Co., Los Padres NF, Antonio R [ca. 35.821°N 121.314°W], below Escondido, 22.v.1977, DDW (12 ♁, 20 ♀, CAS); Napa Co., Hwy 29 [38.655°N 122.605°W], Mtn Mill House, 12 km N Calistoga, 11.vi.1988, 475– 550 m, PHA (1 ♀, USNM); Palm Springs [33°49′N 116°32′W], 19–22.xi.1943, ALM (2 ♁, USNM) ; Riverside Co., Agua Caliente Ind. Res. [33.839°N 116.609°W], Palm Canyon , 25.ii.1970, PHA (1 ♁, USNM); San Diego Co. , San Luis Rey Cpgd [33.274°N 116.851°W], 28vi.1968, PHA (2 ♀, CAS); Tulare Co. , Ash Mtn. [36.491°N 118.831°W], Stn. 3, 23.ix.1995, JFM (1 ♁, CNC); Tuolumne Co. , Lost Claim Cpgd [37.820°N 120.051°W], nr Groveland Ranger Stn, 5–6.vii. 1967, 975 m, PHA (1 ♁, USNM); Tuolumne Co., Sullivan Ck above Phoenix Lk [38.006°, -120.316°], 2500 ft, UV-light, 29.vi.–15.vii.1989, B. Quelvog (♀, CNC) . New Mexico: Catron Co., Gila NF, Whitewater Ck Canyon [33°22′N 108°50′W], 30.v.1991, BJS (4 ♁, CNC) ; Catron Co., 1.5 km E Glenwood, Whitewater Ck [33°18′N 108°53′W], 30.v.1991, BJS (9 ♁, CNC) ; Grant Co., Grapevine Cpgd , 33°10.8′N 108°12.4′W, 6000 ft, Gila River , 15.viii.2007, JCM, CNC103468–472 (2 ♁, 3 ♀, barcoded, CNC) .

Recognition. This species is very similar in colour to R. chillcotti sp. nov. and females appear to be indistinguishable from the latter. Males are distinguished by base of M 1 and M 2 ranging from short to long coalescence, eight short, slender dorsocentral setae, prescutellar depression without pruinescence and clasping cercus narrow, recurved, with stout apical setae.

Redescription. Wing length 3.4–4.1 mm. Male. Face and gena with bluish pubescence. Ocellar setae divergent, weak, shorter than pprn; vertical seta weak and short as ocellar seta. Antenna with short stylus, longer than length of postpedicel; postpedicel ovate, shortly prolonged apically. Length of proboscis four-fifths head height.

Pleura with blue pruinescence ( Fig. 10 ); prescutellar depression without pruinescence; several acr, very short, confined to anterior to first pair of dc; 8 dc, slender, weak, prescutellar seta stronger; 1 pprn; 1 presut spal with several setulae; 2 npl with several anterior setulae; 0 psut spal; 1 pal; 2 sctl and numerous short to long setulae on disc and margin, outer and inner marginal setulae often nearly half length of apical seta; laterotergite with patch of pale setae; antepronotum with several setulae; lower proepisternum with pale setae.

Wing infuscate; cell dm pointed apically, with base of M 1 and M 2 coalesced basally for short to long distance, subequal in length to crossvein dm-m.

Legs dark brown; coxae with bluish pruinescence. Hind tibia with distinct ventral setae, longer than half width of tibia.

Abdominal tergites dark brown, with bluish pruinescence; bearing short black setae. Terminalia ( Fig. 29 ): Hypandrium slightly longer than epandrium, apex rounded; without setae. Phallus slightly curved; membranous distiphallus with pair of elongate, narrow lateral extensions, bearing short, apical sclerotized plates. Cercal plate with several long setae; clasping cercus digitiform, arched posteriorly, with rounded apex; stout, thickened setae along inner apical face and base with narrower inner setae.

Female. Similar to male.

Distribution. This species is known from Arizona, California and New Mexico ( Fig. 34 ).

Remarks. Roederiodes wirthi is sympatric with R. chillcotti sp. nov. in New Mexico, often collected along the same creeks, and in these regions females are indistinguishable.

Figures

FIGURES 8–11. Roederiodes spp. 8, R. distinctus Chillcott, wing, scale bar = 0.5 mm; 9, R. recurvatus Chillcott, wing, scale bar = 0.5 mm; 10, R. wirthi Chillcott, head and thorax, scale bar = 0.5 mm; 11, R. recurvatus, head and thorax, scale bar = 0.25 mm. Abbreviation: dm—discal-medial cell; dc—dorsocentral setae; lbr—labrum; M—medial veins; oc s—ocellar seta; r-m—radial-medial crossvein.

FIGURE 29–30. Male terminalia of Roederiodes, lateral view. 29, R. wirthi Chillcott; 30, R. woodi sp. nov. Scale bars = 0.1 mm. Abbreviations: cl cerc—clasping cercus; distph—distiphallus; epand—epandrium.

FIGURE 31–34. Distribution of New World Roederiodes species. 31, R. browni sp. nov., R. costaricensis sp. nov., R. dedota sp. nov., R. notialis sp. nov., R. wigginsi Wilder, R. woodi sp. nov.; 32, R. chillcotti sp. nov.; 33, R. distinctus Chillcott; 34, R. wirthi Chillcott.