Roederiodes junctus Coquillett, 1901

Sinclair, Bradley J., 2023, Revision of New World species of Roederiodes Coquillett (Diptera: Empididae: Clinocerinae), Zootaxa 5301 (3), pp. 336-364 : 343-345

Roederiodes junctus Coquillett

( Figs 14 , 21 , 35 )

Roederiodes juncta Coquillett, 1901: 585 . Type locality: Saranac Inn , New York, USA.

Roederioides juncta: Chillcott, 1961: 422 [revision]; McCabe & Johnson, 1980: 29 [type catalogue].

Roederiodes junctus: Melander, 1965: 468 [catalogue]; Wilder, 1981: 418 [review]; Sinclair, 1995: 698 [species list]. Roederioides vockerothi Chillcott, 1961: 424 . Type locality: Gainesville, Florida, USA. Syn. nov.

Roederiodes petersoni Chillcott, 1966: 315 . Type locality: Kimball, Snyderville , Utah. Syn. nov.

Type material. Roederiodes junctus : LECTOTYPE ♀, labelled: “Saranac Inn, NY/ July 29, 1900 ”; Type / No.5345/ U.S. N.M. [red label]”; “Roederiodes/ juncta/ Coq.”; “Roederiodes/ needhami/ Coq.”; “LECTOTYPE/ Roederiodes / juncta Coquillett / des. D.D. Wilder 1981 [red label”] ( USNM) . PARALECTOTYPES: same data as lectotype (1 ♁, 1 ♀, USNM; 1 ♀ NYSM) .

Roederiodes petersoni: TOPOTYPICAL SERIES labelled: “ Kimball Cr. / Snyderville UT . [40.730°N 111.547°W]/ 15.viii.1954 / B. V . Peterson (4 ♁, 1 ♀, CNC). PARATYPES : USA. Utah: S. Redwood Rd, Salt Lake City [40°46′N 111°56′W], 15.viii.1954 (4 ♀, CNC) .

Roederiodes vockerothi : HOLOTYPE ♁, labelled: “Gainesville, Fla. [29°42′N 82°23′W]/ 21-IV-1952 / J.R. Vockeroth ”; “HOLOTYPE/ Roederioides / vockerothi/ Chillcott/ CNC No. 7185 [red label]; “ CNC/ 1104798 ” [dissected] ( CNC).

Notes on type material. Coquillett (1901) based his description of R. junctus on three females and one headless male, labelled as follows: “ July 29, 1900, Saranac Inn, N.Y.”, along with the red type label: “Type No. 5345, U.S. N.M”. Two females and one male syntype were found in the USNM, but the red type label was only attached to a single female. The status of the “Type No.” system used by Coquillett has been discussed by several authors (e.g., Sabrosky 1950, 1983; Stone & Knight 1955). These authors concluded that in order to avoid confusion that the phrase “Type No. xxxx” did designate the holotype, a lectotype be selected from a specimen carrying the red type label. As Sabrosky (1983) states, by designating the specimen labelled as “Type” by Coquillett as lectotype, makes the same specimen the name-bearing type whichever side of the question is taken.

It is unclear whether Chillcott (1961) directly examined the type series or simply listed the specimen records, since he listed the information under the heading “Type locality and type”, but did not list the number of specimens or sex. In the type catalogue of the New York State Museum, McCabe & Johnson (1980) identified the holotype of R. junctus , represented by a female specimen with the collection data listed in Coquillett (1901). Although a red co-type label was fixed to this specimen, it did not include the type number and was likely added when the specimen was submitted to the collection. In a review of the genus, Wilder (1981) specifically stated that the holotype in USNM was female, with the type number 5345. Since there is a single specimen in the USNM with this type label, I view this statement of assumed holotype to represent a lectotype fixation (see O’Hara & Cerretti 2016). The specimen is clearly identified as it is the only syntype bearing the type number label. A lectotype label has been attached to this specimen to clarify its status.

The type series of R. petersoni was found to be without type labels and only nine of 29 specimens could be located ( Cooper & Cumming 1993). From the topotypical locality, four males and one female specimen remain. The loss of specimens and absence of type labels are likely in part due to the sudden death of Jim Chillcott in Nepal in 1967, a month following the publication of this species ( Shewell 1967).

Additional material examined. CANADA. New Brunswick: Westmore Co., Scoudouc [46°10′N 64°33′W], Memramcook Rd. , 6.vi.1971, no collector (1 ♁, CNC). Ontario: Algonquin PP, Lk. Sasajewan Dam [45°35′29″N 78°31′09″W], 14.vii.1955, B. V. Peterson (5 ♁, 2 ♀, CNC); same data except, 0.25 mi below North Madawaska R., 16.vii.1955 (3 ♁, CNC); same data except, 30.vi.–17.vii.1955 (4 ♁, 14 ♀, CNC); Algonquin PP, Davies Bog [45°34’N, 78°41′W], 24.v.1955, B. V. Peterson (1 ♁, CNC); Algonquin PP, Wildlife Res. Cp. , 21.v.1955, B. V. Peterson (1 ♁, 1 ♀, CNC); Parry Sound Co., 5 km E Orrville [45°22’N 79°46′W], 6.viii.1989, cascades Seguin R., BJS (1 ♁, CNC). Quebec: Old Chelsea [45°32′N 75°52′W], 3.x.1986, J. R. Vockeroth (1 ♁, CNC); Gatineau Pk, Meech Lk. , Carbide Willson Ruins , 7.x.2021, 45°32′18.45″N 75°52′03″W, sweeping waterfall rocks, BJS, CNC1155786 (1 ♁, barcoded, CNC); Lac Coche , tributary, June 1972? [45.989, -74.004] (1 ♁, QMOR, not examined). USA. Florida: Santa Rosa Co., Blackwater R SF [30.857°N 86.886°W], 23.v.1973, MT, W.W. Wirth (1 ♁, 1 ♀, USNM); Walton Co., DeFuniak Springs [30°43′N 86°7′W], 28.iv.–6.v.1991, Winegarner & Deyrup (1 ♀, CNC). Maine: Pittston [44°11′N 69°42′W], 3.viii.19?0, ALM (1 ♀, USNM). New Hampshire: Black Brook [43.0097°N 71.4756°W], 3.ix.1986, P. Sibley (1 ♁, 1 ♀, DEBU). New York: Adirondacks, Connery Pond [44.310°N 73.937°W], 15.vii.1938, ALM (1 ♁, 1 ♀, USNM); Cold Spring Harbor [40.856°N 73.447°W], 7.vii.1927, ALM (5 ♁, 9 ♀, USNM). Oklahoma: Chickasaw Nat. Rec. Area [34°30′N 96°58′W], 24.v.1991, J.E. Swann (1 ♀, DEBU); Murray Co., Chickasaw Nat. Rec. Area [34°30′N 96°58′W], 24.v.1991, Travertine Ck, BJS (2 ♁, CNC); same data except, CNC103460 , CNC103462 , CNC103458 , CNC103461 (1 ♁, 3 ♀, barcoded, CNC); same data except, J. Swann, CNC103459 (1 ♀, barcoded, CNC); same data except, 13.v.1993, Travertine Ck, JMC (2 ♁, 1 ♀, CNC). South Carolina: Lexington Co., Lexington env. [33°58′N 81°13′W], stream ypans, 24–30.iv.2000, L. Masner, CNC103456 (1 ♀, barcoded, CNC); Oconee Co., Sumter NF, Brasstown Falls [34°34′N 83°18′W], seep nr lower falls, 22.vi.1990, BJS (1 ♁, CNC).

Recognition. This species is distinguished by base of M 1 and M 2 coalesced, five distinct dorsocentral setae, prescutellar depression with white central pruinescent stripe and clasping cercus broad and rounded apically.

Redescription. Wing length 2.6–3.6 mm. Male. Face and gena with bluish pubescence. Ocellar setae divergent, subequal to pprn; vertical seta as long as ocellar seta. Antenna with short stylus, slightly longer than length of postpedicel; postpedicel ovate, shortly prolonged apically. Length of proboscis two-thirds head height.

Pleura with blue pruinescence; prescutellar depression with central whitish or bluish pruinescent stripe ( Fig. 14 ); several acr, very short, extending as far as second pair of dc; 5 dc, with 4th and sometimes 3rd weaker than others; 1 pprn; 1 presut spal with several setulae; 2 npl; 0 psut spal; 1 pal; 2 sctl and numerous short to long setulae on disc and margin, outer marginal setulae 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 distance shorter than to subequal in length to crossvein dm-m.

Legs with coxae and femora pale to yellowish brown; coxae without bluish pruinescence. Hind tibia usually without distinct ventral setae, longer than half width of tibia.

Abdominal tergites brown, without bluish pruinescence; bearing short black setae. Terminalia ( Fig. 21 ): Hypandrium longer than epandrium, apex rounded; without setae. Phallus slightly curved; membranous distiphallus with pair of short lateral extensions. Cercal plate with pair of long setae; clasping cercus broad and rounded, subequal in length to epandrium; inner face with stout, thickened setae over most of inner face; upper margin with several setae.

Female. Similar to male.

Distribution. Roederiodes junctus is rather widespread but appears to be more rarely collected than R. recurvatus . This species ranges from New Brunswick, Ontario and Quebec south to northern Florida, and west to Oklahoma and Utah ( Fig. 35 ). On several occasions, R. junctus has been collected together with R. recurvatus , but appears to be much less common than the latter species.

Remarks. Chillcott (1961) based his figure of the male terminalia on the holotype of R. vockerothi , which was found to be not fully cleared. Upon further removal of the tissue during clearing, the genitalia expanded and the clasping cercus appeared very similar to R. junctus . Examination of the type series of R. petersoni also revealed that if the terminalia is not cleared fully, the form of the clasping cercus and phallus are not fully expanded, which could confuse identification. In addition, the prescutellar depression is pale pruinescent in both type series, which is not present in other North American species. On the basis of the similarity in the shape of the clasping cercus and the pale pruinescent depression, these three species are all considered conspecific.

Wilder (1981) omitted R. petersoni from the key to species in her review of the genus.

Figures

FIGURES 14–15. Roederiodes spp., thorax, dorsal view. 14, R. junctus Coquillett, scale bar = 0.25 mm; 15, R. recurvatus Chillcott, scale bar = 0.25 mm. Abbreviation: sctl—scutellum.

FIGURES 20–23. Male terminalia of Roederiodes, lateral view. 20, R. distinctus Chillcott; 21, R. junctus Coquillett; 22, R. lawrencei sp. nov.; 23, R. moultoni sp. nov. Scale bars = 0.1 mm.Abbreviations: cl cerc—clasping cercus; distph—distiphallus; epand—epandrium; hypd—hypandrium; sur—surstylus.

FIGURE 35–36. Distribution of New World Roederiodes species. 35, R. junctus Coquillett, R. lawrencei sp. nov., R. moultoni sp. nov.; 36, R. recurvatus Chillcott (Gros Morne population in yellow).