Systenus flavifemoratus Bickel

Bickel, Daniel J., 2015, The Costa Rican Systenus Loew (Diptera: Dolichopodidae): rich local sympatry in an otherwise rare genus, Zootaxa 4020 (1), pp. 169-182 : 172

Systenus flavifemoratus Bickel sp. nov.

( Figs 1 c, d)

Type material. HOLOTYPE ♂, COSTA RICA: Guanacaste: 3 km SE Rio Naranjo, 22—25.I.1993, F.D. Parker ( LACM, ex. EMUS; LACM Ent 329995).

Description. Male: body length: 3.1 mm; wing 2.9 x 0.9 mm ( Fig. 1 c); similar to S. tenorio except as noted: Head: palpus yellowish with short black seta and strong apical seta; scape and pedicel yellowish, postpedicel yellowish on the ventral half laterally and ventral two-thirds medially along basal half, otherwise dark brown; postpedicel subrectangular basally and abruptly narrowed to elongate tapering point in distal half, and covered with short pubescence, with antenna overall about 3 times as long as basal width; short apical arista present. Legs: CI entirely yellow; CII and CIII dark brown basally, but distal eighth pale yellow; all trochanters and remainder of legs yellow; CI and CII with white anterior setae and shorter vestiture, CIII with strong while lateral seta at ½; major leg setae black; I: 4.3; 4.0; 2.0/ 1.0/ 0.6/ 0.4/ 0.3; leg I bare of major setation; tibia I and tarsus I with ivory colored (not usual black) short vestiture (MSSC); II: 4.5; 5.0; 2.6/ 2.0/; 1.4/ 0.5/ 0.5; TII with strong ad seta and weaker basally offset pd seta at ¼, and strong pd seta only at 2/3, and with apical ring of ad, pd, av and ventral seta; III: 5.0; 6.3; 1.2/ 2.7/ 1.7/ 1.0/ 0.6; TIII with strong ad seta at 1/5, and with row of 5 black dorsal setae from 1/5 to 4/5, and with apical ring of dorsal, ad and av seta. Wing: vein M bending towards R4+5 just beyond halfway between dm-cu crossvein and apex, and joining costa just behind wing apex; CuAx ratio: 0.6; lower calypter pale yellow with yellowish marginal setae; halter yellow. Abdomen: black with metallic bronze-green reflections and with dusting of grey pruinosity; hypopygium ( Fig. 1 d) dark brown with yellow surstylus and cercus; phallus curved; 2 short epandrial lobes present, each with strong seta; surstylus basally wide and distally up curved and narrowed to a point with some distal setae, and with short dorsal arm appearing separate from base of surstylus; cercus elongate and digitiform, with yellow setae. Female: unknown.

Remarks. Systenus flavifemoratus is known from a single male taken at the Rio Naranjo site, Costa Rica in January. It has the diagnostic male characters of dark brown coxae II and III, with coxa I and remainder of legs being totally yellow, antenna with scape, pedicel and ventrobasal part of postpedicel yellow, with reminder of postpedicel dark brown and surstylus with short dorsal arm appearing separate from the base of the surstylus.

Etymology. The specific epithet “ flavifemoratus ” is Latin, and refers to the yellow femora of this species.

Figures

FIGURE 1. Systenus tenorio sp. nov. (holotype): a. male habitus, left lateral (terminalia removed); b. hypopygium, left lateral. S. flavifemoratus sp. nov. (holotype): c. male habitus, right lateral; d. hypopygium, left lateral. S. maculipennis sp. nov.: e. male habitus, left lateral (terminalia removed); f. hypopygium, left lateral. Abbreviations: cer, cercus; epan, epandrium; hyp, hypandrium; ph, phallus; st, sternite; sur, surstylus; tg, tergite; 6, 7, 8, abdominal segments.