Tachytrechus zumbadoi Brooks

Brooks, Scott E. & Cumming, Jeffrey M., 2008, The Tachytrechus alatus species group (= Syntomoneurum Becker) revisited: new species and revised species group limits (Diptera: Dolichopodidae), Zootaxa 1676, pp. 1-27 : 20-23

Tachytrechus zumbadoi Brooks sp. nov.

(Figs. 10, 11, 12)

Diagnosis. Male. Face and clypeus brownish; 2 notopleural bristles; R4+5 and M slightly converging distally (Fig. 10B); wing membrane evenly infuscated and lacking costal swelling (Fig. 10B); tibiae and basal part of tarsi pale; tarsomere 2 of foreleg with anterodorsal row of long curved hairs (Fig. 10D); tarsomere 2 of midleg longer than basitarsus; hypandrium with elongate ventral projection and lamellate subapical process on right side ( Figs. 11 A, 11B)

Description. Male: Body length 5.7 mm, wing length 5.2 mm. Head (Fig. 10A): Vertex distinctly excavated, vertical seta weak and short, less than half as long as paravertical seta, subequal to upper postocular, pair of strong ocellar bristles, pair of strong paravertical setae. Postoculars mainly white, becoming stronger ventrally, upper three postoculars black, short. Frons blackish with metallic green reflections. Face broad, narrowest at middle. Face and clypeus brownish, lower 2/3 of face and upper third of clypeus darkened with very weak metallic reflections; clypeus rounded below. Palpus white with pale setulae, lacking distinct apical seta. Antenna: Scape subtriangular in lateral view, laterally compressed, blackish dorsally, pale brownish ventrally, about 0.8x as long as pedicel and postpedicel combined; pedicel brown; postpedicel blackish with lower third and ventral margin yellow, ovoid with narrowed apex, about 1.6x as long as wide; arista-like stylus subapical, black with white apex, elongate, about 5x as long as postpedicel, basal article about 0.05x as long as distal article. Thorax: Coloration largely obscured on unique male (see Remarks). Notum metallic green with silvery pruinosity; acrostichals biserial, 6 dorsocentral setae, 1 presutural, 1 sutural, 2 supraalars, 1 postalar, 1 posthumeral, 1 postpronotal with 1–2 weaker setae, 2 notopleural bristles, posterior bristle weak. Pleuron with silvery pruinosity, metaepisternum bare. Scutellum dark greenish-blue with central bronze patch, with strong inner bristle and weak outer seta. Legs: Fore coxa yellow, mid and hind coxae mainly dark, concolorous with thorax; femora mainly yellow, posterodorsal surface of fore and mid femora dark with metallic reflections, distal portion of hind femur weakly infuscated posterodorsally; tibiae yellow; tarsi with tarsomere 1 yellow, darkened apically, tarsomeres 2–5 darkened. Foreleg: Coxa with pale pile and weak setae, apical margin with 2 strong outer and 4 weak inner setae; femur with distinct tubercle behind basal cluster of 2–3 strong setae (Fig. 10C), posterior preapical seta present; tibia with 4 dorsal setae, 2 posteriors and 2 apicals; tarsus slightly longer than tibia, tarsomeres 2–5 weakly flattened laterally, tarsomere 2 with anterodorsal row of curved setae (Fig. 10D), tarsomere ratio: 3.7/2.7/1.8/1.2/1.0. Midleg: Coxa with row of 4–5 weak black setae medial to cluster of strong setae; femur with distinct tubercle on ventral surface proximal to mid-length, 1 strong anterior preapical, 1 distinct posteroventral preapical seta; tibia with 4 anterodorsal setae, 3 posterodorsals, 2 dorsals, 4 strong apicals; tarsus 1.5x longer than tibia, tarsomere ratio: 6.1/8.0/2.1/1.0/1.3. Hindleg: Femur with 1 strong anterodorsal preapical; tibia with 4 anterodorsal setae, 3 posterodorsals, 4–5 weak ventrals, 2 apicals, with or without preapical dorsal seta, with dentiform posteroapical process; tarsus about 1.4x longer than tibia, with hook-shaped posterobasal process opposite apical dentiform process of tibia, tarsomere ratio: 4.0/ 7.9/2.2/1.0/1.1. Wing (Fig. 10B): Veins dark brown, membrane with brownish tinge; costa unmodified, lacking costal swelling; M with weak sinuous bend in distal half; R4+5 and M slightly convergent; crossvein dmcu beyond midpoint of wing, longer than distal section of CuA1. Calypter with black setae. Abdomen: Coloration of sclerites obscured on unique male (see Remarks); tergite 5 with large posterior membranous region, extended laterally as broad band to ventral margin of sclerite; sternite 5 with eversible glandular structure (retracted in holotype); sternite 8 subtriangular with several long setae near posterior margin. Hypopygium ( Figs. 11 A, 11B): Epandrium: Basiventral epandrial lobe elongate, digitiform, with basiventral protuberance, seta present, near base of lobe; apicoventral epandrial lobe short, projected posteriorly, rounded apically with pair of pale setae, medial seta branched apically; accessory epandrial process present medial to apicoventral epandrial lobe. Surstylus: Ventral lobe digitiform, flattened dorsoventrally, with ridged ventral surface, apex with blunt curved seta; dorsal lobe about half as long as ventral lobe, flared apically, apex with setae laterally FIGURE 10. Tachytrechus zumbadoi Brooks sp. nov. male: (A) head; (B) wing; (C) base of foreleg (posterior view); (D) apex of tibia and foretarsus (dorsal view). Abbreviations: A1: anal vein; bv s: basiventral bristle; CuA1: 1st anterior branch of cubital vein; dm-cu: discal medial-cubital crossvein; fem: femur; M: medial vein; pavt s: paravertical seta; R1: 1st radial vein; R2+3: 2nd + 3rd radial vein; R4+5: 4th + 5th radial vein; trc: trochanter; vt s: vertical seta.

and rugose membraneous portion medially. Apicolateral arm of postgonite lacking medial process, apex expanded and granulated. Cercus ( Fig. 11 C) subquadrate in dorsal view, apical and lateral margin darkened, lateral margin with long setae. Hypandrium with lamellate lateral process subapically on right side, with elongate claw-like projection ventrally ( Fig. 11 B). Phallus simple, tubular in distal part, widened in middle section with dorsal projections near middle ( Fig. 11 A).

Female: Unknown.

Type material. Holotype ɗ, COSTA RICA: Puntarenas, Albergue Cerro de Oro, 150 m, 5–12.v.1995, M.A. Zumbado, L_S_279650_518450 #6028, INBIO CRI 002 307704 ( INBC).

Distribution. Tachytrechus zumbadoi is known only from the type locality in the province of Puntarenas, Costa Rica ( Fig. 12 ).

Etymology. The specific name is a patronym in honor of Instituto Nacional de Biodiversidad dipterist, Manuel Zumbado, who collected the holotype of this species.

Remarks. The coloration of the thorax and abdomen of the male holotype is largely obscured by a dark, greasy coating.

Figures

FIGURE 11. Tachytrechus zumbadoi Brooks sp. nov. hypopygium: (A) left lateral view; (B) ventral view (postgonite, surstylus and cerci not shown); (C) cercus (dorsal view). Abbreviations: acc proc: accessory epandrial process; apv lobe: apicoventral epandrial lobe; bv lobe: basiventral epandrial lobe; cerc: cercus; epand: epandrium; hypd: hypandrium; pgt: postgonite; ph: phallus; vsur: ventral lobe of surstylus.

FIGURE 12. Known distribution of Tachytrechus costaricensis Brooks sp. nov., T. transversus (Van Duzee) and T. zumbadoi Brooks sp. nov.