Diagnosis. See E. pseudoilicis for differences with that species. Ilicis and heringella are the only western Palaearctic oak-mining species with dorsal spot only. Fomoria septembrella (Stainton), Stigmella catharticella (Stainton) and Zimmermannia species also have dorsal spot only, but this is situated postmedially, whereas it is medial in ilicis. This is also the case in E. intimella, but this species can be separated by its unicolorous antennae, uniform dark scales on the forewings, and hair-pencil in the male. See heringella for differences with that species. The mines are easily confused with haraldi, but adults are easily separated by totally different valva in male and the distinct row of setae on T7 and form of T8 in female of ilicis.
Description. Male. Forewing length 2.48 — 3.36 mm (2.87 ± 0.25, 13), wingspan 5.6 — 7.2 mm. Head: frontal tuft and collar yellowish orange. Antennae with 31 — 40 segments (37 ± 2.5, 13); scape white, with sometimes some brown scales. Thorax and forewings brown, with a dorsal spot only in medial position, sometimes slightly extending along dorsal margin towards base; sometimes a few scattered white scales present in addition. Hindwing without hairpencil, but with costal bristles.
Female. Forewing length 2.36 — 2.88 mm (2.68 ± 0.16, 10), wingspan 5.1 — 6.5 mm. Antennal segments 28—31 (30.1 ± 1.0, 8).
Male genitalia. Capsule length 231—244 μm (240 ± 6.1, 5). Tegumen broad and rounded. Gnathos with central element undivided, slightly truncate, lateral margins serrate. Valva length 176—193 μm (183.4 ± 7.0, 5), inner margin basally straight or convex, from 1/3 distinctly concave, inwards pointed tip prominent, truncate. Aedeagus 253 — 274 m (264 ± 9.9, 5), carinae split into two or more spines each.
Female genitalia. T7 with a distinct row of 8-14 long setae along anterior margin of T8. T8 with two groups of about 3 — 6 setae, scales absent; T8 narrow with slightly sinuous posterior margin. Anal papillae with 8-14 setae. Vestibulum with vaginal sclerite, a dorsal spiculate pouch and a group of densely packed pectinations near the entrance of ductus spermathecae. Corpus bursae 660 — 825 μm, without pectinations; signa dissimilar, longest 407—471 μm (432.9 ± 26.9, 5), shortest 369— 416 μm (395.1 ± 19.3, 5), 3.9—5.1 x as long as wide. Ductus spermathecae with 2 indistinct convolutions.
Larva. Yellow with conspicuous brown ganglia. Head light brown. Ventral plates absent.
Hostplants: evergreen oaks Quercus ilex L., Q. rotundifolia Lam., Q. suber L. and Q. coccifera L. (Van Nieukerken 1985; Nieukerken et al. 2004a; 2006). Mine usually not separable from other sympatric gallery mines (E. algeriensis, coscoja, haraldi), but compared with haraldi, the frass is often more broken and the mine more contorted.
Only in Southwestern Europe and Northwest Africa (Van Nieukerken 1985; Nieukerken et al. 2004a; 2006).
Life History. Univoltine, with larvae from January to March and adults flying from April to July.
This taxonomic description is based on Van Nieukerken (1985) and Van Nieukerken et al (2010).