Paraclius arcuatus
Creators: name: Soares, Matheus M. M.
name: Runyon, Justin B.
name: Capellari, Renato S.
name: Ale-Rocha, Rosaly
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Paraclius
Paraclius arcuatus

description: Paraclius arcuatus (Loew)
(Figs 2–6, 22)
Pelastoneurus arcuatus Loew, 1861: 39. Type locality: Cuba.
Paraclius arcuatus: Loew, 1864: 101.
Paraclius femoratus Aldrich, 1901: 340 Type locality: Mexico, Veracruz, Teapa, and Frontera. Syn. nov. Diagnosis (males). Postpedicel subrectangular, pointed dorsally at apex (Fig. 2E). Scutellum with apical pair of short setae between pair of larger marginal setae (Figs 2B, 6C). Legs mostly yellow, except extreme base of coxa I, basal 2/3 of coxa II, basal 1/2 of coxa III, apical 1/3 to 1/2 of femur II, apical 1/2 of femur III, tarsi I and II from apical 1/2 of tarsomere 1, tibia III (except basal 1/4 of dorsal surface dark yellow) and all of tarsus III brown to dark brown (Figs 2A, 4A, 6A). Wing mostly brown; M 1 strongly bowed towards R 4 +5, and strongly concave posteriorly; CuAx ratio: 0.6 (Figs 2F, 4A, 5A, D). Male tergite 6 bare (Figs 2D, 3A). Basal apicoventral epandrial seta slightly longer than apical seta and ventral lobe of surstylus. Ventral lobe of surstylus long and narrow, somewhat L-shaped, gently curved ventrally at apex (Fig. 3C, D). Dorsal lobe of surstylus short and wide, with acute apical process and with 2 strong setae at middle, 1 long at dorsal edge and 1 shorter at inner edge (Fig. 3F). Cercus somewhat drop-shaped, whitish yellow, about 1/3 as long as epandrium (Fig. 2D).
4+5
Redescription. Male (based on identified specimens). Body length: 2.0– 2.7 mm; wing length: 1.9–2.3 mm, width: 0.6–0.7 mm (n = 12). Head (Fig. 2A–C). Upper-most 5–6 and the lower-most postocular setae black, remaining setae white. Frons subrectangular, 2.5X wider than high, metallic green with weak bluish-purple reflections, covered with weak yellowish gray pruinosity. Face ground color pale brown, but obscured by dense silvery pruinosity, except rectangular area below the base of antennae, which is metallic green with weak coppery reflections; face gradually narrowing below (funnel-shaped), as wide as mid ocellus at narrowest point. Clypeus rectangular, 2X higher than wide, about 1/4 as long as face, lower margin straight, ending close to lower eye margin. Palpus short, oval, and brown, covered with short black setae near apex and 1 stronger seta at apex (shorter than palpus). Proboscis brown, labellum with few slender and short pale setae; prementum with row of pale slender setae at apical edge. Postcranium dark green, covered with weak yellowish gray pruinosity, silvery and dense at region between eye margin and postocular row of setae; lower postcranium with 4 strong white setae along ventral margin and with few pale short and slender setae below the occipital foramen. Pair of divergent strong ocellar setae and pair of tiny postocellar setae; pair of strong convergent vertical setae; pair of short paravertical setae, slightly longer and aligned with the upper-most postocular seta. Antenna (Fig. 2E) dark brown; scape conical, dorsal surface covered with short black setae, 1 longer dorsal seta at apex, inner surface with long acute process, and ventral surface with short acute process; pedicel short, with a crown of setae and 1 longer dorsal seta at apex; postpedicel subrectangular, pointed dorsally at apex, 1.5X longer than wide, covered with dense whitish pubescence; arista-like stylus dorsal, arising at base of postpedicel, about 4/6 of eye height, two-segmented, first segment short, slightly overlapping the apex of postpedicel, covered with short pubescence, second segment long, 2X longer than first segment, covered with short microtrichia. Thorax (Fig. 2A, B). Mesonotum mostly metallic green, except with weak coppery acrostichal stripe extending along acrostichal setae, one dark spot above notopleuron, extending from the sutural intra-alar seta to above the base of wing, mesonotum covered with coppery pruinosity in anterior view, notopleuron covered with dense silvery pruinosity in dorsal view and a small patch of silvery pruinosity posterior to the postalar callus in posterior view. Scutellum metallic green, with weak bluish reflections. Pleura brown, covered with silvery pruinosity and weak greenish reflections mainly on the anepisternum; one short and rounded yellow spot at lower 1/2 of anepisternum, above coxa I. Metepimeron grayish brown. Chaetotaxy: Pronotum with row of strong and short black setae; anterior 1/6 of mesonotum covered with short black setae; acrostichals biseriate, short, increasing in length posteriorly, ending at level of the fourth posterior dorsocentral seta; 5 pairs of strong dorsocentrals increasing in length posteriorly; 1 pre-, 1 sutural and 1 postsutural intra-alars; 2 strong supra-alar setae, 1 positioned between postpronotal lobe and notopleuron and 1 near postalar callus; 1 strong, 1 short and 1 minute postpronotals; 2 strong notopleurals, 1 at middle of lower edge and 1 at posterior margin of notopleuron, slightly shorter than preceding seta; 1 strong postalar; scutellum with 1 pair of strong medial scutellar setae, 1 pair of smaller setae laterad and 1 pair of short apical setae, laterad and apical setae about 1/5as long as medial scutellars; upper-surface of proepisternum with 2–3 short black setae immediately in front of anterior spiracle, and a few fine white setulae on upper and lower surfaces; lower surface with 1 strong black seta; metepisternum with row of fine setulae. Wing (Fig. 2F). Long and narrow, about 3X longer than wide, anal lobe barely developed; membrane brown to light brown. Costa ending before wing apex, at M 1; R 1 ending at basal 3/8 of wing; R 2+3 slightly curved anteriorly towards apex; R 4+5 nearly straight, slightly curved posteriorly at apex; M 1 strongly bowed towards R 4+5, and strongly concave posteriorly, almost closing cell r 4+5; cell bm+dm ending at 4.5/8 of wing; M 4 fading apically, not reaching wing margin; CuA+CuP ending at basal 1/3 of cell bm+dm, not reaching wing margin and fading apically; length of crossvein dm-m/last part of M 4 (CuAx ratio): 0.6. Lower calypter yellow with black setae; halter yellow to whitish yellow; anterior and posterior surfaces of halter knob with group of short setae; plumule yellow. Legs (Figs 1A, 4A, 6A). Mostly yellow, except extreme base of coxa I, basal 1/2 of anterior surface of coxa II and entire lateral surface of coxa II, basal 1/3 of lateral surface of coxa III, apical 1/2 to 1/3 of femur II and apical 1/2 of femur III, tarsi I and II from apex of tarsomere 1, and tibia and tarsus III brown to dark brown. Leg I. Podomere ratios: 25, 25, 8/3/3/2/3. Anterior surface of coxa I covered with short vestiture of setae (with few erect setae near base), outer edge with 2 strong setae, 1 at middle and 1 near apex, apical edge with 2 strong and 2–3 slender setae. Femur I covered with short vestiture of setae, except ventral surface mostly bare, with anteroventral row of short setae from base to apex (about 1/3 as long as width of femur at broadest point) ending in 2 preapical more conspicuous setae and 2–3 conspicuous posteroventral preapical setae. Tibia I with 1 conspicuous anterodorsal seta at 2/6, row of short setae from basal 2.5/6 to apex, 2 short posterodorsal setae at 1.5/6 and 5/6, 2 dorsal setae at 3.5/6 (long) and 5/6 (short). Ventral surface of tarsus I from apex of It 1 to It 5 with weak whitish pile (MSSC). Leg II. Podomere ratios: 33, 33, 15/10/10/7/4. Anterior surface of coxa II covered with short vestiture of setae, and with fringe of long setae at middle, outer edge with 1 long and strong seta at middle, apical edge with 3 strong setae. Femur II covered with short vestiture of setae, with anteroventral row of setae from base to apical 5/6 (about 1/2 as long as width of femur at broadest point) ending in 1 long preapical seta, 1 short posterior preapical seta and 1 strong anterior preapical seta. Tibia II with paired anteroand posterodorsal setae at 1/6 (about half-length of second pair), 1.5/6 and 4.5/6, 1 strong anterodorsal seta at 2.5/6, 1 strong anteroventral seta at 3/6 and 1 short ventral seta at 3.5/6 and crown of strong setae at apex: 1 antero- and 1 posterodorsal, 1 dorsal, 1 antero- and 1 posteroventral. Tarsus II unmodified. Leg III. Podomere ratios: 34, 44, 12/17/12/8/5. Lateral surface of coxa III with 1 strong and 1 slender seta at apical half, apical edge of anterior surface with 2–3 short setae. Femur III laterally compressed, about 1.5X wider than femur II at broadest point, covered with short vestiture of setae, with dorsal row of more erect setae from base to apical 4/6 (about 1/3 as long as width of femur), with anteroventral row of setae from base to apical 4/6 (about 1/3 as long as width of femur) ending in 1 longer preapical seta, 1 short posteroventral preapical seta, and 1 strong anterodorsal preapical seta. Tibia III with paired antero- and posterodorsal setae at 0.5/6 (about half-length of second pair), 1/6, 2.5/6, 1 strong anterodorsal seta at 4/6, 1 short ventral seta at 4/6, 1 dorsal, 1 anterior and 1 ventral strong preapical setae, ventral row of sparse and erect setae from basal 2/6 to apical 4/6. Tarsus III unmodified. Abdomen (Figs 2A, D, 3A, B). Metallic green, tergites 1–5 covered with short vestiture of black setae and long setae at posterior margins, slightly shorter than tergites, except on tergite 5 with setae slightly longer; tergites 1–5 with weak lateral patches of silvery pruinosity and coppery and greenish reflections. Tergite 6 brown, bare, covered with silvery pruinosity in posterior view and weak greenish reflections. Tergite 7 covered with weak pruinosity and wide membranous area at middle. Sternites (Fig. 3A) brown to pale brown. Sternite 1 largely membranous, with narrow sclerotized and curved area posteriorly, slightly widening at lateral margins. Sternite 2 weakly sclerotized, with more sclerotized area at middle, somewhat C-shaped. Sternite 3 divided in two subtriangular hemitergites at anterior margin and entirely membranous at posterior margin. Sternite 4 C-shaped, curved anteriorly and very narrow at middle. Sternite 5 glasses-shaped anteriorly, divided in two 0-shaped sclerites posteriorly, with large lateral weakly sclerotized area connected with sternite 6. Sternite 6 plate-shaped, with posterior membranous region connected with tergite 6. Tergite and sternite 7 fused at apex, forming long and well sclerotized peduncle. Sternite 8 subovoid, covered with long black setae at posterior edge. Hypopygium (Figs 2D, 3C–G). Epandrium brown, long and narrow, about 2.5X longer than high, with acute apicoventral lateral ridge (Figs 2D, 3C). Apicoventral epandrial lobe not developed, 2 apicoventral epandrial setae present, basal seta slightly longer than apical seta and ventral lobe of surstylus (Fig. 3G), 1 short basiventral epandrial seta present. Ventral lobe of surstylus long and narrow, somewhat L-shaped, gently curved ventrally at apex, with stout modified apical seta (Fig. 3D). Dorsal lobe of surstylus short and wide, with acute apical process and with 2 strong setae at middle, 1 long seta at dorsal edge and 1 shorter seta at inner edge (Fig. 3F). Postgonite plain, short, about 1/2 as long as ventral lobe of surstylus, well sclerotized and slightly curved ventrally at apex (Fig. 3D). Undivided proctiger brush present, blunt and covered with short pubescence at apex (Fig. 3D). Hypandrium trough-shaped, with weak connection to epandrium basally, free laterally, apex bifurcate and membranous, lateral margin with 2 dentiform preapical processes, base of hypandrium projecting up inside epandrial capsule, cradling phallus (Fig. 3C–E). Phallus strongly sclerotized, divided in two narrow arms, narrowing at apex, left arm with 1 subapical short process (Fig. 3D); ejaculatory apodeme long, about 3/5 as long as epandrium, slightly widening at apex, laterally compressed and well sclerotized (Fig. 3D); sperm pump short, somewhat C-shaped, about 1/3 as long as ejaculatory apodeme (Fig. 3D). Basal sclerite of sperm pump short and narrow, somewhat Cshaped in ventral view. Cercus short, drop-shaped in dorsal view, about 1/3 as long as epandrium, whitish-yellow, outer surface covered with short setae; ventral edge with strong setae (Fig. 2D). Female (Figs 4–6). Body length: 2.2–3.0 mm; wing length: 2.2–2.5 mm (n = 13). Similar to male, except as noted: postpedicel suboval, as long as wide (Figs 4C, 5C); face and clypeus wide, both wider than ocellar tubercle (Figs 4B, 5C). Abdomen with 5 visible and setose segments (Figs 4A, 5A, 6A), tergites 6 and 7 with deep concavity at anterior 1/2. Sternites 6 and 7 unmodified. Tergite and sternite 8 divided medially, fused anterolaterally, forming narrow sclerite. Tergite 10 divided medially into hemitergites, each bearing 5 short spines and 1 minute lateral seta, innermost pair sometimes slightly offset, spines rounded and somewhat flattened apically.
Type material examined. Pelastoneurus arcuatus: LECTOTYPE ♀ (based on photographs) (Fig. 5) labelled as: “ Cuba [green label]”; “arcuatus”; “206”; “ Loew | Coll.”; “ Type | 13026” [red label]; “MCZ-ENT | 00013026” (MCZ). Lectotype condition: good, glued to a piece of paper, left postpedicel broken off, not dissected.
Paraclius femoratus Aldrich: SYNTYPE ♀ (based on photographs) (Fig. 6) labelled as: “[Mexico] Vera Cruz. | April. H.H.S.”; “Collection | JMAldrich”; “Cotype | No. 50470 | U.S.N.M.”; “ Paraclius | femoratus | Ald.” [handwritten] (NMNH).
Additional material examined. BELIZE: Cayo Dist. Sibun River & Hwy [ca 17°10′36.6″N 88°36′11.3″W] 30.xi.2001, river shore, L. Masner, YPT (2 ♁, one dissected, CNC); Toledo District, Deep River at Medina Bank, N 16°26.592′ W 88°44.704′, 20.iii.2019, J.B. Runyon (1 ♀, METC); Guanacaste N.P. 11.xi.2001, roaring crk [ca 17°15′52.5″N 88°47′48.0″W], L. Masner, YPT (3 ♀, CNC); Stann Creek, 3km S Hopkins [ca 16°50′07.5″N 88°16′02.2″W], 24–25.xi.2001, mangrove, YPT, L. Masner, CNC 810957 (1 ♁, CNC); BARC, nr. San Pedro, Columbia, 16°17′0″N 88°58′0″W, MT & YPT, 10–12.iii.2002, J. Skevington, CNC 361120 (1 ♀, CNC). COSTA RICA: Prov. Guanacaste, Santa Rosa Nat’l Park, N 10°50.9′ W 85°36.8′ 300 m, along road near headquarters, 16.viii.2010, J.B. Runyon (1 ♀, CNC); La Caja, 8 kil. W. San Jose [ca 9°55′05.8″N 84°06′27.1″W], Costa Rica, Schmidt 1930, Paraclius arcuatus (Loew) det. Fred C. Harmston, Collection of Calif. Acad. of Sci. 1994, gift Fred C. Harmston, CASENT 8416961, Paraclius arcuatus det. S.E. Brooks, 2003 (1 ♁ dissected, CAS). CUBA: [Santiago de Cuba], Boniato [ca 20°05′08.8″N 75°48′13.8″W], xii.2.04 [02.xii.1904], MCVanDuzee Collection, Paraclius femoratus Ald., Collection of the California Academy of Sciences, San Francisco, Calif., CASENT 8416912 (1 ♁ dissected, 1 ♀, CAS); [San Jose de las Lajas] Lomas de Camoa [ca 22°57′59.5″N 82°11′00.3″W] 14.iii.1952, Dodge & Seago, Paraclius sp. det. Fred C. Harmston, CASENT 8416925 (1 ♁, CAS). GUATEMALA: Ingenio R. R. Sta. [ca 14°14′25.7″N 90°50′31.5″W], 28.iv [1926], JMAldrich collector, Paraclius arcuatus Lw. (1 ♁ dissected, NMNH); Pt Barrios [ca 14°38′56.4″N 91°53′01.4″W], 03–14.iii.1905, MCVanDuzee Collection, Paraclius femoratus Ald. (1 ♁, CAS). HONDURAS: Roatán Island, West Bay, N 16°17′00″ W 86°35′52″, 23– 25.xi.2012, L. Masner, YPT creek (5 ♁, one dissected, 3 ♀, CNC); La Ceiba [ca 15°45′21.0″N 86°48′13.2″W], 13.xii.1915, FJDyer Coll (2 ♀, NMNH). JAMAICA: [ca 18°06′10.3″N 77°16′14.9″W], JMAldrich collection (3 ♀, all dissected, NMNH). MEXICO: [San Luis Potosí], El Salto [ca 22°21′45.1″N 99°15′56.7″W], 09.v.1963 (2 ♁, one dissected, 2 ♀, NMNH); Veracruz, Lake Catemaco [ca 18°25′05.5″N 95°06′37.5″W], 01.v.1969, H.J. Teskey (1 ♀, CNC); same data, except: 16.vi.1969, B. V. Peterson (5 ♀, CNC); Huichihuayán [ca 21°28′46.1″N 98°58′03.9″W], 25.viii.1988, L.J. Lipovaky (1 ♁, CNC); Chiapas, Motozintla [ca 15°21′46.0″N 92°14′43.4″W], 3000’ [= 900 m], 06.vi.1969, B. V. Peterson (Mal. Tr) (1 ♀, CNC). NICARAGUA: Leon Zarzales [ca 12°39′44.0″N 86°26′30.5″W], 12.x.1988, J.M. Maes (1 ♁, 1 ♀, MTEC).
Remarks. Paraclius arcuatus is the only species in the arcuatus -group with 1 pair of short apical setae on scutellum, femur II brown on apical 1/3 to apical 1/2 and femur III brown on apical 1/2, male tergite 6 bare and male terminalia with an undivided proctiger brush. It is noteworthy that this is the only species in the group with plesiomorphic condition of bare tergite 6 in males (Brooks 2005, character 36), but also with longer setae arising from the posterior margin of tergite 5, which probably perform the same sensorial function of setae on tergite 6. Peter Dyte (unpublished manuscript) noted a similar situation in males of Chrysotus Meigen and Diaphorus Meigen, with long setae on the posterior margin of tergite 6 and sternite 8 respectively. These setae might play a role in perceiving and preventing other males approaching from behind before starting courtship.
Examination of the female syntype of P. femoratus Aldrich (the only specimen present at NMNH) (Fig. 6) revealed that it is a synonym of P. arcuatus, by the typical leg color and the apical pair of scutellar setae (Fig. 6C). Aldrich stated that the female of P. femoratus has a narrow face, similar to male, but it is likely that the author analyzed a male with the hypopygium broken off or strongly embedded into abdomen.
Negrobov & Maslova (2004) stated that P. amazonae Parent (as P. amasonae) is “possibly a junior synonym of P. femoratus ”. Nevertheless, based on genitalic characters, that species is probably related to P. flavicauda Van Duzee and not part of the arcuatus -group.
Distribution. Cuba and newly recorded from Belize, Costa Rica, Guatemala, Honduras, Jamaica, Mexico and Nicaragua (Fig. 22).
description: Published as part of Soares, Matheus M. M., Runyon, Justin B., Capellari, Renato S. & Ale-Rocha, Rosaly, 2023, Review of Paraclius arcuatus species-group (Diptera, Dolichopodidae) with description of two new species, pp. 151-182 in Zootaxa 5323 (2) on pages 155-162, DOI: 10.11646/zootaxa.5323.2.1, http://zenodo.org/record/8204101