Ophiomyia galiodes, Lonsdale, 2021

Lonsdale, Owen, 2021, Manual of North American Agromyzidae (Diptera, Schizophora), with revision of the fauna of the " Delmarva " states, ZooKeys 1051, pp. 1-481 : 1

Ophiomyia galiodes sp. nov.

Figs 346 , 347

Description.

Wing length 2.2 mm (♂), 1.9-2.2 (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.6-1.0. Eye height divided by gena height: 6.2-9.8. Facial carina (wide dorsally) and bulb distinct. Parafacial, seen laterally, broadly rounded and projecting past anterior margin of gena. Gena slightly produced anteriorly, forming an angle of ca. 70° and with dorsal and ventral margins straight, not curved. Clypeus broadest posteriorly; apex very narrow, produced. Buccal cavity narrowed anteriorly with margin straight. Ocellar triangle concave subapically. Frons slightly furrowed medially. Crossveins separated by more than length of dm-m.

Chaetotaxy: Vibrissal fasciculus well-developed, slightly upcurved. Two ori; two ors. Mid tibia without posteromedial setae.

Colouration: Body, including halter dark brown, but relatively pale compared to congeners. Fronto-orbital plate and outer margin of ocellar triangle beige. Wing veins white. Calypter margin light brown with hairs brown.

Genitalia: (Figs 346 , 347 ) Surstylus slightly <1/2 length of epandrium, with several marginal tubercle-like setae. Metepiphallus pale and largely desclerotised with one pair of small ventromedial spines. Proepiphallus pigmented medially, darker ventrally. Halves of basiphallus broadly fused at base with remainder of left sclerite absent; right sclerite relatively short and ill-defined; strongly bent ventrally (possibly an artifact of preservation). Distiphallus short, strongly spinulose internally and with base extending past that of mesophallus; membrane distal to phallus relatively broad, flat, and lightly sclerotised.

Host.

Rubiaceae - Galium .

Distribution.

USA: MD.

Etymology.

The specific name indicates the similarity of this species to its possible sister taxon, Ophiomyia galii , which also feeds on Galium .

Type material.

Holotype: USA. MD: Beltsville, 16.iv.1975, S.W.T. Batra, ex. Galium sp. (1♂, USNM).

Paratypes: USA. MD: Same collection as holotype (1♀, USNM; 1♀, CNC).

Comments.

The phallus of Ophiomyia galiodes (only illustrated in lateral view due to inflexibility of the structure) is similar to that of O. laticolis (Figs 368 , 369 ), but the distiphallus is narrower, larger and closer to the apex of the basiphallus. Furthermore, the eye is larger, rounder and bulging anteriorly, and the shoulders, fronto-orbital plate and ocellar triangle are pale, although these colour characters may be an artifact of preservation.

Ophiomyia galiodes is also similar to the European O. galii Hering, which is the only other Ophiomyia known from Galium (Spencer, 1990). Their chaetotaxy, wing length and wing vein proportions are nearly the same, and they both have a ventrally curved hypandrium and similar distiphallus. The gena of O. galii is produced at a 45° angle (not 70°) ( Spencer 1972), the basiphallus is longer and less spinulose, and the mesophallus is longer, narrower and extends past the base of the distiphallus ( Papp and Černý 2015: fig. 152).

Figures

Figures 346 - 350. Ophiomyia galiodes Lonsdale, sp. nov. 346 hypandrial complex, left lateral 347 external genitalia, ventral 348 - 350 O. heleios Lonsdale, sp. nov. 348 hypandrium, ventral 349 hypandrial complex (excluding hypandrium and proepiphallus), left lateral 350 phallus and proepiphallus, ventral.

Figures 367 - 371. Ophiomyia laticolis sp. nov., male genitalia 367 hypandrium, ventral 368 hypandrial complex, left lateral 369 phallus, ventral 370 external genitalia, left lateral 371 external genitalia, posterior.