Diagnosis: easily separated from most Ectoedemia species by presence of a medial dorsal spot only on forewing. Distinguished from ilicis and heringella by more uniformly dark forewings, hair-pencil in male, and the flagellum being the same colour as the scape: it is the only treated Ectoedemia, with this character. Species of Fomoria, Stigmella or Ectoedemia (Zimmermannia) with dorsal spot only, have it in postmedial position.
Male. Forewing length 2.4 — 2.84 mm (2.58 ± 0.15, 16), wingspan 5.3 — 6.3 mm. Head: frontal tuft and collar intensively ferruginous to yellowish orange. Antenna with 39 — 45 segments (41.3 ± 2.0, 12), scape, pedicel and flagellum yellowish white, with an orange tinge. Thorax and forewings uniformly blackish fuscous, with a faint purplish gloss, scales almost uniformly dark; a yellowish white dorsal spot in middle of forewing, conspicuous. Hindwing with a very short ochreous hair-pencil, less than 1/5 of hindwing length.
Female. Forewing length 2.48 — 3.04 mm (2.75 ± 0.19, 7), wingspan 5.6 — 6.8 mm. Antenna with 27 — 30 segments (28 ± 1.1, 6). Ovipositor protruding, pointed.
Male genitaha (figs. 97, 239, 289, 359). Capsule length 287—304 μm (294.3 ± 8.0, 6). Tegumen produced into wide, triangular pseuduncus. Gnathos (fig. 289) with central element very wide, uniformly rounded. Valva (fig. 239) length 210—236 μm (217.1 ± 9.3, 6), basally broad, suddenly narrowed in middle with inner margin becoming strongly concave; tip pointed. Aedeagus (fig. 359) 317—364 μm (340.3 ± 18.3, 5), with pair of slender, pointed ventral carinae, sometimes bifid, and pair of pointed dorsolateral carinae with additional spines.
Female genitalia (figs. 157, 158, 429). T7 with a row of 6 — 8 setae along posterior margin. T8 narrowed posteriorly, with two lateral groups of 11 — 16 short and long setae. Anal papillae narrow, with 14 — 15 setae. Vestibulum with vaginal sclerite, a dorsal spiculate pouch with comparatively few (less than 40) spines, all single and equally spaced; patch of densely packed pectinations near opening of ductus spermathecae. Corpus bursae 505 — 605 μm, without pectinations; signa dissimilar, longest 304 — 347 μm (4), shortest 257—313 μm (4), 4.9—5.5 x as long as wide. Ductus spermathecae with 2½ — 3 convolutions.
Larva. Pale yellow. Sternites present on proand mesothorax and abdominal segment 10. Ventral plates absent.
Hostplants: Salix caprea L., S. cinerea L., S. pentandra L., S. fragilis L., S. phylicifolia L., S. dasyclados Wimm. (Ellis 2007). In Finland a population of E. intimella was discovered feeding on Populus balsamifera L. These mines resemble those of E. hannoverella, but the mine usually enters the leaf blade further away from the petiole and the larva doesn’t show the characteristic plates of E. hannoverella (Gustafsson and Nieukerken 1990).
Mine (fig. 477). Egg on upperside, against midrib. Early mine in midrib, later becoming large elongate blotch at one side of midrib, with black frass deposited in two lateral lines, such that larva can pass in between to conceal itself in midrib. Only final instar larva mines in leafblade.
Widely distributed in northern, western and central Europe. Norway: Aarvik et al. 1997; Ireland: Shackleton 1977; Latvia: Šulcs and Šulcs 1989; Lithuania: Ivinskis et al. 1985.
In the south it is known from northern Italy, Spain, Slovenia, Slovakia and Rumania.
For new French records: Van Nieukerken et al. 2006, here we record it new from southern France. Also found in far eastern Russia: Sakhalin (Puplesis 1994). Here for the first time recorded from Japan, Hokkaido, not far from Sakhalin.
Life history. Univoltine, larvae in September to November, adults from May to July.
This taxonomic description is based on Van Nieukerken (1985) and Van Nieukerken et al (2010)