Diagnosis. The combination of short pale-tipped antenna, strong metallic lustre on forewing (coppery proximal part suffused with purple at least along costa) and metallic fascia make ulmivora immediately recognizable.
Male. Wingspan: 4.8-5.4 mm. Head: frontal tuft dark fuscous to blackish; scape white or yellowish white; collar dark fuscous; antenna slightly less than half length of forewing, dark fuscous, distal quarter distinctly paler. Thorax concolorous with base of forewing. Forewing: area proximal to fascia shining coppery with slight to heavy purple tinge; fascia postmedial, shining silvery to brassy; shape of fascia variable, normally narrowed and sometimes obliterated at costa; distal to fascia dark purple fuscous; terminal cilia concolorous but paler at tips. Hindwing: dark greyish brown; with slender, brown androconial scales at dorsum and costa, sometimes indistinct; androconial scales extending over fringe to almost one-quarter length of cilia. Abdomen fuscous.
Female. Wingspan: 5.0-5.6 mm. Antenna distinctly shorter than half length of forewing. Hindwing without androconial scales. Otherwise similar to male.
Male genitalia. Vinculum with anterior margin broadly emarginate; lateral corners long and pointed. Uncus with shallow emargination in hind margin, projections subtruncate, margins more sclerotized than rest of uncus. Tegumen about as wide as uncus. Gnathos with short transverse bar, long horns and long anterior processes. Valva triangular, arcuate; inner lobe very narrow and indistinct; setae on dorsal side distally divided into two or three much finer tips. Transtilla with long, triangular sublateral processes. Juxta constricted in middle. Aedeagus about as long as genital capsule; most of vesica covered by large spines and dentate plates.
Female genitalia. Bursa copulatrix three-quarters length of abdomen. Accessory sac rather large, tapering and convoluted distally; reticulate field absent. Corpus bursae large and oval, completely covered with pectinations. Proximal part of ductus spermathecae broad, with close-set spines. Apophyses posteriores and anteriores of approximately same length, short.
Host plant: Ulmus spp. Egg: on underside near a rib. Larva: bright green. Mine : very variable depending on thickness of leaves; mines in sun exposed leaves are short and almost straight and mines in shaded leaves are long, narrow galleries; deposition of frass varies from a thin central line (in long mines) to the mine being almost completely filled (in short mines). Larval exit slit always on leaf-underside. Cocoon: leather brown.
From NEJ and eastern Denmark; in southern Sweden up to Vstm.; not in Norway and Finland. - Widely distributed throughout Europe.
Voltinism: bivoltine; adults of the summer generation are scarce.
Description based on Johansson and Nielsen (1990)