A fasciate species, recognized by the other fasciate species by the unedged scape, the absence of androconiae and the relatively dark wingbase. Female genitalia resemble those of S. omelkoi, but T8 very wide and short, bursa covered with pectinations and ductus spermathecae with fewer convolutions.
Male. Forewing length 2.1-2.6 mm (2.04 ± 0.73, n=9), wingspan 4.2-5.4 mm. Head: frontal tuft pale yellow to orange; collar brown; scape silvery white, not edged, flagellum brown. Antennae with 31-34 segments (31.13 ± 3.09, n=8). Thorax and forewings brown, forewing basal 1/3 shining brown-bronze, at 2/3 a silvery metallic fascia, slightly wider at dorsum, cilia-line distinct, terminal cilia silver; underside forewings dark brown. Hindwing brown on both sides. Abdomen brown, anal tufts hardly visible.
Female. Forewing length 2,1 mm (n=1), wingspan 4.6 mm. Antenna with 24 segments (n=1). Underside forewing and hindwings grey. Abdominal tip blunt.
Male genitalia. Capsule length 245 µm (n=2). Vinculum anteriorly slightly concave. Uncus with widely separated hooklike processes, truncate, but inwards hooked tips, slightly arched in-between. Gnathos with long posterior processes, in middle less sclerotized. Valva length 150-155 µm (n=2), with strongly inwards curved distal process of more than 1/3 valva length, inner margin rectangular; sublateral processes long. Aedeagus 315-320 µm long (n=2), short and wide; vesica with many cornuti of same size, one big cornutus at phallotrema; manica present, but inconspicuous and without spines.
Female genitalia. T8 very wide and short, no distinct furrows or rims, with about 16 setae centrally, ca. 4 laterally. Anterior apophyses short. Total length bursa ca. 1200 µm (n=1), basal part of ductus and accessory sac heavily folded; bursa thin, covered with small pectinations; accessory sac covered with strong pectinations Ductus spermathecae with about 3 convolutions.
Hostplant. Quercus mongolica, a deciduous oak.
Leafmines. Egg on leaf-upperside, between veins, sometimes close to margin. Early mine an extremely contorted gallery, doubling back several times, closely following earlier track, so that early mine forms a brown dot; this is further enhanced because the leaf around the mine stains pale brown; the frass in this part is brown, dispersed or coiled, often filling mine completely. Later the mine widens, but continues to double back, only in its final part it may follow a looser course; frass coiled or dispersed, black, filling about half the gallery width. Mine rarely crossing a vein.
Larva. Yellow, with pale head; ganglia not visible. Feeding dorsum upwards.
Primorskiy Kray and Heilongjiang.
Life history. Bivoltine, larvae found in June-July and September. Adults fly in June-July, spring generation not yet known.
This taxonomic description is based on Van Nieukerken (2000).