Diagnosis. Characterised by brown irrorate with yellow forewings and absence of hair-pencil in male. Male genitalia not separable from albifaseiella complex. Female genitalia characterised by long spiraled ductus spermathecae, with 13½ - 14 convolutions, whereas contorta usually has 10½ — 12 convolutions (except one specimen).
Description.
Male. Forewing length 2.0 — 2.68 mm (2.43 ± 0.19, 9), wingspan 4.3 — 6.0 mm. Head: frontal tuft ferruginous, sometimes mixed with fuscous; collar similar. Antennae with 28 — 37 segments (32.5 ± 3.2, 6). Thorax and forewings brown irrorate with light yellow scales, being a more pronounced yellow than in most other species; colour pattern absent, but light scales predominant at tornus. Hindwing without hairpencil, but with costal bristles.
Female. Forewing length 2.72 — 2.88 mm (2.79 ± 0.07, 4), wingspan 6.0 — 6.4 mm. Antennal segments 25 — 27 (2.8 ± 1.0, 4).
Male genitalia. Capsule length 283 — 309 µm, (3). Tegumen rounded. Gnathos with central element truncate, as cut off. Valva length 206 — 223 μm (4), inner margin strongly convex, except apically, serrate by prominent setal sockets, tip pointed; dorsal surface with many setae. Aedeagus 279 — 287 μm (4), carinae pointed, single.
Female genitalia. T7 with a row of 8 — 12 setae along posterior margin; T8 with two lateral groups of scales and 2 — 4 setae each. Anal papillae with 14 — 17 setae. Vestibulum with vaginal sclerite, a dorsal spiculate pouch, and a group of densely packed pectinations near entrance of ductus spermathecae. Corpus bursae 740 — 825 μm, without pectinations; signa dissimilar, longest 485 — 695 μm (3), shortest 450 — 458 μm, 4.1 — 4.4 x as long as wide (3). Ductus spermathecae with very prominent spiralised inner canal, with 13½ — 14 convolutions.
Larva. Yellow, with greenish tinge in younger larvae, head-capsule brown. In penultimate instars with conspicuous brown ventral plates, which are shed during final instar; thereafter the ganglia become visible.
Hostplants: Quercus pubescens Willd., Q. petraea (Matt.) Liebl. Mine. Egg on leaf underside, occasionally on upperside. Early mine highly contorted, forming brown blot with irregularly accumulated brown frass; later gallery less contorted, with brown dispersed or coiled frass, leaving narrow clear margins. Mine confined to small area, often near leaf-margin.
Widespread, but nowhere common in southern half of Europe; not yet found on Iberian Peninsula and in most Balkan countries. Known from Czech republic, Slovakia, Hungary, Austria and Italy.
Also found in France: Van Nieukerken et al. 2006; Macedonia: Laštůvka and Laštůvka 1997, detailed record given here; Greece (northern): Laštůvka and Laštůvka 1998, Switzerland: Schmid 2007. Here recorded new for Bulgaria.
Life history. Univoltine, larvae occurring from mid October to November. Adults collected at light mid June, reared in April and May (forced).
This taxonomic description is based on Van Nieukerken (1985) and Van Nieukerken et al (2010).