Diagnosis: externally almost inseparable from albifasciella-complex, see key-characters. Male genitalia characterised by two pairs of similar, curved carinae and triangular gnathos. Female genitalia differ by combination of pectinate bursa and slightly dissimilar signa, which are much shorter than in albifasciella-complex.
Male. Forewing length 5.6 — 6.0 mm (2.63 ± 0.09, 6), wingspan 5.6—6.0 mm. Head: frontal tuft and collar yellowish orange to ferruginous. Antennae with 36 — 39 segments (37.2 ± 1.2, 6). Thorax and forewings blackish fuscous, thorax without white scales at tip of mesoscutum and tegulae; forewing with yellowish white, not shining spots: one dorsal in middle, and one costal before middle, sometimes united to form fascia. Hindwing without hair-pencil but with costal bristles.
Female. Forewing length 2.56 — 2.68 mm (2.62 ± 0.06, 5), wingspan 5.7 — 6.0 mm. Antennae with 27 — 3 1 segments (29 ± 1 .6, 5).
Male genitalia. Capsule length 257 — 317 µm (4). Tegumen produced into broadly triangular pseuduncus. Gnathos with central element triangular, pointed. Valva length 214 µm (3), widest at base, inner margin serrate by prominent setal sockets, tip rounded; posterior margin with a notch, in ventral view suggesting a double tip. Aedeagus 330 — 334 µm (4), with a dorsal and dorsolateral pair of strong, curved carinae of same length, dorsal pair often overlapping; aedeagus slightly constricted.
Female genitalia. Abdominal tip narrow. T7 with a row of 6 — 12 setae along posterior margin. T8 approximately quadrate, with two groups of 1-4 setae, without scales. Anal papillae with 12 — 19 setae. Vestibulum with vaginal sclerite, a dorsal spiculate pouch with many spines, both single and in rows, and a dense patch of pectinations near entrance of ductus spermathecae. Ductus bursae densely covered with pectinations. Corpus bursae 550 — 790 µm, covered with small pectinations, except anterior part; signa ovoid, slightly dissimilar in length, longest 369 — 441 µm (3), shortest 330 — 394 µm (3), 2.4 — 3.0 x as long as wide. Ductus spermathecae with 2 ½ — 3 ½ convolutions.
Larva. Whitish, with distinct ganglia. Penultimate stages with 12 dark brown ventral plates, which are shed during final instar. See detailed description by Klimesch (1941).
Hostplants: Ulmus spp. Egg on either side of leaf, on a vein. Early mine narrow, much contorted gallery, with frass in widely separated pellets, then abruptly widening into elongate blotch, with blackish frass concentrated in basal half or at margins, often absorbing early gallery.
Known from the Danube valley, near Vienna and Budapest, although not always near the river. Slovakia: Laštůvka et al. 1992; Italy: Karsholt et al. 1995; Laštůvka and Laštůvka 2005; Bulgaria: mines recorded by Beiger 1979; 1980, Tomov and Krusteva 2007, here confirmed by an adult; Greece: Laštůvka and Laštůvka 1998. Also found in far eastern Russia (Puplesis and Diškus 2003) and in northeastern China (Van Nieukerken unpublished).
Life history. Univoltine, larvae September to October, adults fly from April to June.
This taxonomic description is based on Van Nieukerken (1985) and Van Nieukerken et al (2010).