M a t e r i a l e x a m i n e d. Near Volokhiv Yar, 22.05.2011, 1 ♂, 1 ♀; near Rubizhne, 20.05.2012, 1 ♀; near Krasnoye, 23.05.2012, 1 ♂, 2 ♀; near Orchik, 23.05.2009, 1 ♀; Pyatykhatki, 10.06.2010, 1 ♂; Stara Pokrovka, 12.06.2012, 1 ♂; near Petrivske, 25.06.2011, 1 ♀.

R e d e s c r i p t i o n. Head (fig. 25, 26, 29). Orbit strongly projected above eye in profile; 2 orb s, 2 fr s; frorb sta short, sparse, reclinate; keel lacking; lunule very small, rounded; ocellar triangle extremely small, reaching the level of 2nd orb s, matt; maximal height of eye 3.2 × maximal height of gena; 1st flagellomere small, rounded (lateral view); gena angled anteriorly (lateral view); proboscis very long.

Wing. Costa reaching M; last section of M 1.15 × as long as penultimate; calypter grey, fringe and margin black. Length of wing 1.9–2.5 mm.

Mesonotum black, matt (anterior view); 2 dc; ac 2 nearest to sctsctl sut and 7 at level of 2nd dc; halter and legs brown.

Рис. 25–31. O. longilingua (Hendel): 25, 26 — голова самца; 27 — фаллюс, латеральный вид; 28 — то же, вентральный вид; 29 — голова самки; 30 — левая лопасть восьмого стернита; 31 — сперматека. Масштабная линейка 0,1 мм.

Male genitalia (fig. 27, 28). Phallus 0.17 mm long. Phallus atypical for Ophiomyia, with basiphallus 3.2 × as wide as distiphallus (ventral view). Endophallus oval, located nearby basiphallus. Distiphallus small, narrow, taking place distally in phallus complex.

Female terminalia (fig. 30, 31). Both spermathecae equal, spherical, with narrow cylindrical collar. Proximal margin of egg guide with well-marked sharp, elongated teeth, directed posteriorly. Membrane of medial margin with big dark scales in two irregular rows.

D i s t r i b u t i o n. Widespread but not common in Europe (Austria, France, Greece, Switzerland (Spencer, 1976), Latvia, Lithuania (Pakalniškis, 1994), Ukraine (Guglya, 2011, 2012)).

H o s t p l a n t. Dipsacaceae: Knautia arvensis (L.) Coult (Spencer, 1990, Pakalniškis, 1994).

B i o n o m i c s. Larva forms reddish shallow mines in the stem immediately beneath the epidermis. Pupation takes place in the ground (Spencer, 1976, 1990).