Diagnosis. Male with distinctive black forewing and white basal patch, scape with black distal part and black androconia on hindwing. Female resembles A. minimella and A. pistaciae, but has a dark frontal tuft and darker forewing. In genitalia it differs from the previous three species by valval lobe, which is simply triangular and not as elaborate as in the other species. In the female genitalia A. loranthella is recognised by wider signa than in previous three species, about 7 cells wide.
Description. Male. Forewing length 1.8–2.4 mm, wingspan 3.7–5.5 mm. Head: frontal tuft fuscous; collar greyish, paler; scape white, distal ⅓ to more than ½ black. Antenna grey, with 30–39 segments. Thorax black, with few scattered greyish white scales; forewing covered with black scales, white elongate patch in costal half near base, not reaching costa and variable amount of pale grey scales around this patch, and in dorsal half forming elongate, almost linear, patch; terminal 1/5 white with grey, cilia silvery white. Underside with black scaling at base and in narrow strips along costa and dorsum, rest of underside devoid of scales, white patch shining though, black scaling appearing grey. Hindwing silvery white, frenulum and costal bristles present; patch of black scales covering basal 1/6–1/5; underside similar, with similar black patch. Abdomen silvery grey, with white inconspicuous anal tufts.
Female. Forewing length 2.1–2.5 mm, wingspan 4.5–5.5 mm. Antenna with 33–36 segments. Frontal tuft fuscous to brown, collar ditto. Scape yellowish white, no black scaling. Thorax and forewing yellowish brown to ochreous, irrorate with dark brown scales; cilia silvery white; special scales absent; costal bristles present, hindwing silvery white. Abdomen grey ochreous.
Male genitalia. Measurements: see Table 3. Vinculum anteriorly concave, ventral plate rather long. Tegumen small, more or less triangular; uncus band-shaped, with indistinct central process, in lateral view split distally; gnathos with long narrow central element. Valva triangular because of triangular basal inner process, not clearly separated from valva; apex slightly pointed. Transtilla without transverse bar, sublateral process short. Aedeagus with bifurcate pointed carinae, ventrally tightly fused to ventral process; pair of curved dorsal carinae present; vesica with numerous small cornuti and several larger cornuti.
Female genitalia. T8 narrow, two small lateral groups of scales and setae. Anal papillae conspicuous, with 23-27 setae. Apophyses straight, slender. Total bursa length ca. 730–800 μm. Vestibulum with elaborate sclerotisations. Ductus bursae covered with pectinations. Corpus bursae elongate, without pectinations; with wide (up to 7 cells wide) and long (ca. 305–345 μm) reticulate signa, margins crenate. Ductus spermathecae with ca. 2 inconspicuous convolutions and small vesicle.
Final instar larva. Head capsule ca. 290–315 μm wide. Mandibular cusps pointed. A9 with 3 pairs of setae. Integument covered with rather long microtrichia (ca. 7–16 μm long) on all segments except A10. Otherwise as group description.
Hostplant. Loranthus europaeus (Loranthaceae), an obligate parasite growing on branches of Quercus species and Castanea sativa.
Egg on either side of leaf, mine developing on the side where the egg is deposited. Leafmine a gallery throughout, often starting as a spiral mine, the coils amalgamating to form a small blotch, gallery often crossing earlier course, thereby forming a false blotch. Frass brownish, starting as broken linear tract, later slightly coiled or dispersed, filling one third to one half of mine width; exit hole on the same side as the egg and the mine.
Occurs with host in South eastern Europe: Czech Republic, Slovakia, eastern Austria, Hungary, Italy, Sicily, Rumania and Greece. To be expected throughout Balkan peninsula and in Turkey.
This taxonomic description is based on Van Nieukerken (2007).