Diagnosis. The coarsely scaled forewing in combination with tornal spot separates catharticella from all European species of the malella group except the south European alaternella (Le Marchand). The male genitalia are characteristic by the many large triangular cornuti and the peculiar cathrema.
Male. Wingspan: 4.6-5.5 mm. Head: frontal tuft ochreous, orange or ferruginous; scape and collar yellowish white; male antenna distinctly longer than half length of forewing. Thorax concolorous with base of forewing. Forewing: coarsely scaled, dark grey; proximal part of scales pale grey, distal part dark fuscous and with faint purple gloss; with triangular, sometimes indistinct white spot at tornus; terminal cilia silvery grey beyond a more or less defined line of dark-tipped scales. Hindwing: greyish brown. Abdomen fuscous, sometimes with faint purple tinge; with short brownish anal tufts.
Female. Wingspan: 5.1-5.5 mm. Antenna slightly shorter than half length of forewing. Abdomen without anal tufts. Otherwise similar to male.
Male genitalia. Vinculum with broad emargination from anterior margin; corners rounded. Uncus with small, triangular projections; lateral margins most strongly sclerotized. Tegumen narrower than uncus, rounded. Gnathos with broad central element and short horns. Valva short compared to length of genital capsule; inner lobe narrow, tapering into distal process. Transtilla with subtriangular sublateral processes. Aedeagus slightly shorter than genital capsule; vesica with 30-35 large, triangular cornuti and a patch of smaller and thinner spines near tip; cathrema with well sclerotized, curved posterior extension.
Female genitalia. Bursa copulatrix approximately half as long as abdomen. Accessory sac rounded. Reticulate field small and indistinct. Ductus spermathecae short with two to three indistinct convolutions; vesicle ovoid, well sclerotized. Corpus bursae almost completely covered with small rounded spots of pectinations, except a patch devoid of pectinations at approximately midlength. Apophyses posteriores distinctly longer than anteriores.
Host plant: Rhamnus catharticus. Egg: on underside of leaf, close to a rib. Larva: green. Mine : at first a slender often straight gallery, frequently running along margin of leaf; the mine bends twice or more; frass dark greenish, completely filling mine, coiled in last third. Mine and larva often almost invisible in leaf owing to their colour. Cocoon: yellow.
In eastern Denmark and southern Sweden up to Upl. Absent from Norway (we are unable to confirm Grönlien's (1932) record) and only known from Al in Finland. - In northern and central Europe, from England to Austria.
Voltinism: bivoltine.
Description based on Johansson and Nielsen (1990)