Diagnosis. Externally characterised by light head and collar, almost straight non-metallic fascia and in male yellowish-white hair-pencil and white tuft on underside forewing. Male genitalia characterised by aedeagus without carinae and valvae with serrate inner margin and inconspicuous tip. Female genitalia characterised by absence of both vaginal sclerite and spiculate pouch, and by dissimilar signa.
Description. Male. Forewing length 2.42 — 2.52 mm (4), wingspan 5.0 — 5.6 mm. Head: frontal tuft and collar yellowish-orange. Antennae with 34 — 36 segments (4). Thorax and forewings blackish, with medial, almost straight, non-shining fascia, often interrupted. Underside of forewing with a tuft of white hair-scales arising near costal retinaculum and a large scaleless area. Hindwing with a yellowish-white hair-pencil. Female. Forewing length 2.2 — 2.32 mm (2.25 ± 0.04, 7), wingspan 4.8 — 5.4 mm. Antennae with 26 — 27 segments (26.8 ± 0.5, 5). Without characteristics on underside forewing. Male genitalia. Capsule length 266 — 287 µm (2). Tegumen produced into prominent triangular pseuduncus. Gnathos with central element very short and inconspicuous, with wide truncate tip. Valva length 206—214 µm (2), inner margin approximately straight, but serrate by prominent setal sockets; tip an inconspicuous, pointed, inwards directed process. Aedeagus 244 — 266 µm (2), without carinae, a simple tube. Female genitalia. T7 with 6—8 short setae in an indistinct row along posterior margin. T8 appearing as a double sclerite: with two lateral patches of scales and 6 — 7 long setae. Anal papillae with 13 — 16 setae. Vestibulum smooth, without sclerite or spiculate pouch. Corpus bursae 650 — 660 µm, sparsely covered with small spines or pectinations; signa clearly dissimilar, longest 394 — 441 µm (3), shortest 321—343 µm (3), 3.8—3.9 x as long as wide. Ductus spermathecae with 2½— 3 convolutions. Larva not examined.
Hostplant: in Europe only Spiraea media F. Schmidt, in East Asia probably also on other species of Spiraea, although S. media has a large distribution throughout Siberia as far as Japan (Sokolov et al. 1980). Mine. Egg on leaf-underside against midrib, often in axil between midrib and lateral vein. Early mine linear, straight, following a vein, or occasionally leaf margin, filled with brown, dispersed frass; later abruptly widening into wide, irregular blotch, with blackish dispersed frass. Leafmines may be confused with those of Stigmella inopinata A. & Z. Laštůvka (Laštůvka and Laštůvka 1990a), they only differ in the more jagged early mine of spiraeae versus a straight one in S. inopinata.
In Europe only known from a very small area near the border of Hungary and Slovakia (see also Laštůvka and Laštůvka 1991), widespread in East Palaearctic. A new record from western Siberia is given here.
Life history. Univoltine, larvae from July to October, they appear in some years (e.g. 1990) in July after a cold spell, in other years not before September or October (Laštůvka and Laštůvka 1991). Adults from May to July.
This taxonomic description is based on Van Nieukerken (1985) and Van Nieukerken et al (2010).