Manual of North American Agromyzidae (Diptera, Schizophora), with revision of the fauna of the " Delmarva " states Author Lonsdale, Owen Agriculture & Agri-Food Canada, 960 Carling Avenue, Ottawa, ON, K 1 A 0 C 6, Canada neoxabea@hotmail.com text ZooKeys 2021 2021-07-29 1051 1 481 http://dx.doi.org/10.3897/zookeys.1051.64603 journal article http://dx.doi.org/10.3897/zookeys.1051.64603 1313-2970-1051-1 639E252D43924ABB910BCEA5D8AD2487 BE8CC6847F645F61BB2F7A6BCF96FD64 Ophiomyia capitolia sp. nov. Figs 332-336 Description. Wing length 1.7 mm (♂). Female unknown. Length of ultimate section of vein M4 divided by penultimate section: 0.8. Eye height divided by gena height: 6.2. Eye slightly angled diagonally. Facial carina stout, slightly more narrow than stout bulb. Gena shallowly produced, projecting at 60° angle with margins straight. Clypeus narrow and truncated. Buccal cavity narrowed anteriorly with anterior margin straight. Distance between crossveins more than length of dm-m. Ocellar triangle and fronto-orbital plate (narrow) subshiny and ill-defined. Chaetotaxy : Male with vibrissal fasciculus ~ 1/2 length of gena. Two ori; two ors. Mid tibia with one posteromedial seta. Colouration : Body, including halter dark brown. Wing veins brown. Calypter margin and hairs brown. Genitalia : (Figs 332-336 ) Metepiphallus small, pale and with one pair of ventromedial spines. Epiphallic lobes clear with dark floating sclerite. Halves of basiphallus broadly fused at base with remainder of left sclerite absent; right sclerite relatively short and truncated with long distoventral process reaching venter. Mesophallus continuing distally as thick ridge that bifurcates apically; distiphallus pale and globular with inner surface minutely spinulose. Ejaculatory apodeme with long dark stalk and several annulations on striated blade; sperm pump with weak sclerotisation. Host. Unknown. Distribution. USA : DC. Etymology. The specific name refers to the fact that the type was collected in the United States capitol. Type material. Holotype : USA. DC : Washington, 17.viii.1913, A.L. Melander (1♂, USNM). Comments. Ophiomyia capitolia is one of the smaller Delmarva Ophiomyia with a male wing length of 1.7 mm. This species also has a distinct genal process, a long fasciculus and a relatively distinct wrinkle under the eye within the cheek. Only examination of the male genitalia can provide reliable identification of this species (see key).