Diagnosis. S. anomalella can frequently be separated from all other unicolorous species by pale greenish bronzy forewing with distinctly darker purplish-brown to purplish-fuscous distal part and, in the male, a patch of darker scales at base of hindwing. The male genitalia of anomalella and S. centifoliella are very similar (centifoliella has fascia on forewing!), but the larger cornuti in anomalella are pointed (blunt in centifoliella) and the smaller cornuti sparse (numerous in centifoliella). The female genitalia of the two species are exceedingly similar, but anomalella can normally be recognized by its larger accessory sac and longer ductus spermathecae.
Male. Wingspan: 5-6 mm. Head: frontal tuft varying from ochreous or yellowish brown to dark fuscous (in Scandinavia usually fuscous); collar yellowish white; scape white; antenna approximately half length of forewing. Forewing: shining greenish bronzy, tinged with copper on base of costa; distal quarter well-defined purplish brown to purplish fuscous; terminal cilia concolorous but paler at tips. Hindwing: pale grey brown, basal third with patch of distinctly darker scales. Abdomen: dark fuscous with faint purple tinge. Female. Wingspan: 5.5-6.5 mm. Antenna slightly shorter than half length of forewing. Hindwing without dark scales at base, other- wise similar to male. Male genitalia. Vinculum with distinct concavity in anterior extension; lateral corners narrow. Uncus with two short, rounded protuberances with heavily sclerotized margins. Gnathos with short transverse bar and moderately long horns. Valva with pointed, arcuate distal process and small rounded inner lobe, constricted at base. Lateral arms and transverse bar of transtilla forming a U-shaped band without sublateral processes. Aedaegus slightly shorter than genital capsule, vesica with 6-8 small and a few smaller spines in two groups.
Female genitalia. Bursa copulatrix approximately threequarters length of abdomen. Accessory sac relatively large. Reticulate field large, but indistinct. Ductus spermathecae half length of bursa copulatrix, anterior part widened and with one or two convolutions. Corpus bursae large, oval and almost completely covered with long and thin pectinations. Apophyses anteriores and posteriores of equal length, straight and slender.
Host plants: Rosa sp., both wild and cultivated, Potentilla caulescens (in the S. Alps), Sanguisorba officinalis and S. minor. Egg: generally on the underside and close to a rib. Larva: yellow, with a single row of darker dorsal spots. Mine : a long, gradually widening gallery which usually follows the margin of the leaf; first part normally filled with frass, thereafter with dense, broad central frass-line leaving clear margins. It is frequently not possible to separate the mine and larvae of the three species of the anomalella group here treated. Cocoon: red to red brown, usually found at the base of the leaf or the leaf-stalk.
From almost all districts in Denmark and in Sweden up to Hrj. Norway: Ak. In southern Finland up to Sb. - Widely distributed in Ireland and Britain and throughout continental Europe, the Canary Islands. Puplesis (1985a) reports the species from east USSR.
Voltinism: bivoltine; larvae often found until very late in the autumn. Occurs later than centifoliella.
Description based on Johansson and Nielsen (1990)