The Costa Rican Systenus Loew (Diptera: Dolichopodidae): rich local sympatry in an otherwise rare genus Author Bickel, Daniel J. text Zootaxa 2015 4020 1 169 182 journal article 10.11646/zootaxa.4020.1.7 82b2f539-5d25-42d6-95c5-e8b16a353e12 1175-5326 237970 BD8D1880-79A9-4672-99AF-5B3D1BEFAFEE Systenus parkeri Bickel sp. nov. ( Figs 4 c, d, e) Type material . HOLOTYPE ♂, COSTA RICA : Guanacaste: 3 km SE Rio Naranjo, 20.XI.1991 , F.D. Parker ( LACM Ent 320003). PARATYPE ♂, same but 22–25.I.1993 ( LACM , ex. EMUS ). ( LACM Ent 320004). Description . Male : body length: 3.2 mm ; wing 3.0 x 0.1.0 mm ( Fig. 4 c); similar to S. tenorio except as noted: Head : proboscis yellow, projecting anteriorly, keel-like; antennal scape, pedicel and basal half of postpedicel yellow and distal tapering half of postpedicel dark brown; scape and pedicel short; 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 yellow; CII and CIII mostly dark brown, all trochanters, and remainder of legs yellow; CI and CII with white anterior setae and shorter vestiture, CIII with strong white lateral seta at ½; major leg setae black; I: 4.5; 4.0; 2.0/ 1.4/ 1.0/ 0.4/ 0.4; leg I bare of major setation; tibia I yellow with brownish short vestiture; II: 4.3; 4.7; 2.7/ 1.7/ 1.2/ 0.8/ 0.6; TII with strong ad seta and weaker pd seta at ¼, and strong ad seta and small pd seta at 2/3, and with apical ring of ad, pd, av and ventral seta; III: 4.0; 5.2; 1.0/ 1.6/ 1.0/ 0.6/ 0.5; TIII with ad-pd setal pair near 1/8, without white vestiture, and with 4 black dorsal setae, and with apical ring of dorsal, ad and av seta. Wing : CuAx ratio: 0.9. Abdomen : tergites 1–4 mostly metallic bronze-green with dusting of grey pruinosity, and tergites 3–4 with anterior margin metallic black; tergites 5–7 mostly dark metallic green; posterior margin of tergite 1 with posterior row of long black setae, tergites otherwise covered with short black vestiture; segment 7 forming elongate peduncle, with sternite 7 glabrous and tergite 7 covered with short black vestiture; sternite 8 dark brown forming cap-like cover over hypopygial foramen on left side of epandrium; hypopygium ( Figs 4 d, e) dark brown with yellow surstylus and cercus; epandrium short and subrectangular; epandrial lobe with long and short apical seta; surstylus basally expanded with numerous pale setae and tapering to curved subrectangular apex; cercus relatively short, subrectangular, broad basally and narrowed to wide recurved apex, and with short yellow hairs. Female : unknown. Remarks . Systenus parkeri is known from two males taken at the Rio Naranjo site, Costa Rica , collected in November and January. It has the diagnostic male characters of the postpedicel basally subrectangular and yellow basally and abruptly narrowed to elongate dark brown tapering point in distal half, legs mostly yellow, tibia I yellow, not white, and cercus short, wide and subrectangular. Etymology . This species is named in honor of Frank Parker, emeritus Utah State University, who collected extensively in Latin America and provided most of the specimens used in this study.