Diagnosis. Externally resembling S. torminalis and S. crataegella; see diagnosis under these species.
Male. Wingspan: 4.5-5.0 mm. Head: frontal tuft ferruginous to ferruginous orange; collar dark fuscous; scape white; antenna almost half as long as forewing. Forewing: area proximal to fascia dark golden brown with purple tinge, sometimes such that this part seems purple; post- medial fascia broad and brassy, sometimes indistinct; dark purple fuscous distal to fascia; terminal cilia concolorous but paler at tips. Hindwing: fuscous with purple black androconial scales at dorsum, extending over fringe to, at most, one-third length of cilia. Female. Wingspan: 4.6-4.8 mm. Head: antenna distinctly shorter than half length of forewing. Hindwing: greyish brown, without androconial scales. Otherwise similar to male. Male genitalia. Vinculum with small lateral corners; excavation of anterior extension appearing almost uniformly concave. Uncus bilobed with thickened margins. Gnathos with moderately long horns and long anterior processes. Valva with distinct distal process and rounded inner lobe; posterior margin of inner lobe almost at right angle to distal process. Aedeagus slightly longer than genital capsule; most cornuti triangular, larger cornuti more pointed. Female genitalia. Bursa copulatrix small, less than half length of abdomen. Accessory sac comparatively small, bent; reticulate field distinct. Ductus spermathecae shorter than bursa copulatrix.
Host plant: Crataegus spp. and occasionally on Mespilus germanica. Egg: usually on underside; usually on or near leaf margin. Larva: yellow, head pale brown. Mine : early mine very narrow and completely filled with brown coiled frass; usually following leaf margin; when the larva reaches the final instar, the mine turns abruptly and follows same leaf margin again, becoming a large blotch with thin line of blackish, dispersed or coiled frass; the early mine often becomes completely absorbed in the blotch. The very similar mine of S. hybnerella can be distinguished by blackish, broken dispersed frass in early mine, leaving clear margins; the mine of hybnerella is often not near margin of leaf. The egg in hybnerella is not deposited near leaf margin, but in most cases on upperside. Cocoon: red.
In eastern Denmark, including F. In Sweden up to Upl. Not in Norway and Finland. - Widely distributed in Europe, from England to France and Italy and western USSR (Schoorl et al., 1985).
Voltinism: variable, in the north probably univoltine. According to Emmet (1976, 1979) usually univoltine in Great Britain with larvae from August to November, but occasionally bivoltine. In the Netherlands partly bivoltine with larvae (in June and July and from August onwards). Adults emerge in May and July-August. Larvae are usually found in shady places, in woods.
Description based on Johansson and Nielsen (1990)