Diagnosis. Largest Ectoedemia from Europe, distinguished form preceding five species by orange head, absence of white spots on forewing and lower number of antennal segments. Differs from externally similar, but lighter, liguricella, by presence of hair-pencil in male and lower number of antennal segments, in both sexes. Male genitalia characteristic with short and wide aedeagus, configuration of carinae and broad triangular valvae. Female genitalia especially characterised by long spiraled ductus spermathecae, absence of long hairs on T8 and spines in vestibulum.
Description. Male. Forewing length 3.2 — 3.92 mm (3.72 ± 0.15, 6), wingspan 7.8 — 8.8 mm. Head: frontal tuft and collar orange to ochreous. Antennae not very long, with 36 — 41 segments (3). Thorax and forewing uniformly brown irrorate with white, without white spots; cilia lighter but cilia-Hne very inconspicuous. Hindwing with snowwhite hair-pencil, approximately 1/3 of hindwing length, with a row of white scales along costal margin, but no specialised scales along dorsal edge; humeral lobe prominent, costal emargination present beyond hair-pencil. Female. Forewing length 3.84 — 4.52 mm (3), wingspan 8.8 — 9.8 mm. Antennal segments 36 — 37 (3). Male genitalia. Capsule length ± 420 µm (2), capsule very wide, 369 — 373 µm (2). Vinculum with very short ventral plate. Tegumen broadly rounded, not produced. Gnathos with wide triangular central element. Valva length 270—280 µm (2), triangular, comparatively wide, tip curved slightly inwards, dorsal surface with indistinct serrate lobe. Aedeagus 369 — 420 µm (5), gradually widening from anterior end towards wide posterior end; ventral carinae broadly triangular, separated, inner margin serrate; lateral carinae indistinct, rounded; dorsal carinae comprising a row of 4 — 5 teeth; surface of aedeagus between ventral and lateral carinae with minute spines. Vesica with one broad triangular cornutus in addition to numerous small cornuti. Female genitalia. T8 with a row of 16 — 18 setae along anterior margin and 4 — 10 small setae on disc, scales absent. Anal papillae with 15 — 21 seatae. Posterior apophyses clearly reaching beyond anterior apophyses. Vestibulum with two groups of spines, one near opening of ductus spermathecae and one opposite. Corpus bursae 1430 — 1640 µm , covered with pectinations, partly in concentric bands around signa; signa similar, 527 — 594 µm (4) long, ± 4 x as long as wide. Ductus spermathecae with 12^2 — 13 convolutions.
Host plant: Ulmus spp. The species has not been reared, but often caught on Elm on which barkmines were observed (Johansson, pers. comm., Larsen, 1981). Barkmines often found in association with adults (Nieukerken et al., 2010). Mine (fig. 474). A long contorted gallery in smooth bark of rather thin branches, similar to that of atrifontella.
Southern Sweden, Denmark: Bornholm and Falster, Austria: Vienna region, and Macedonia. Norway: Van Nieukerken and Johansson 1990, Germany: Pröse 2006, Biesenbaum and Rutten 2008; Great Britain: Dickerson 1995; 1996; France: Van Nieukerken et al. 2006; Poland: Laštůvka and Laštůvka 1997 (records below); Czech Republic: Laštůvka and Laštůvka 1991; Laštůvka et al. 1992; Slovakia: Laštůvka and Laštůvka 1991; Hungary: Laštůvka and Laštůvka 1997; Slovenia: Laštůvka and Laštůvka 1997; Croatia: Laštůvka and Laštůvka 1997; Ukraine (Crimea): Budashkin 1988; Puplesis 1994; Italy: Karsholt et al. 1995; Laštůvka and Laštůvka 2005; Greece: Laštůvka and Laštůvka 1998, Azerbaijan: Puplesis 1994. Here recorded for the first time from Bulgaria, first detailed records for Azerbaijan, Croatia and Hungary, a second record for Italy and a third and fourth for France. It also occurs in the East Palaearctic (Puplesis 1994) and is here recorded for the first time from China and Japan.
Life history. Not studied, but probably similar to that of liebwerdella.
This taxonomic description is based on Van Nieukerken (1985) and Van Nieukerken et al (2010).