Diagnosis. Externally easy to separate from most other species by pale colour and size. Resembles Trifurcula pallidella (Duponchel), but male easily distinguished by yellow patch on forewing underside. Male genitalia characterized by triangular valva and triangular, symmetrical gnathos, but see puplesisi.
Description. Male. Forewing length 2.6-2.9 mm, wingspan 5.6-6.7 mm. Head: frontal tuft yellowish orange, collar yellowish white. Antenna with 34-37 segments; scape yellowish white, sometimes with a few dark scales. Forewing and thorax covered with fuscous tipped scales, mixed with white scales, giving a grey-brown impression; terminal cilia white beyond relatively distinct cilia-line. Underside of forewing with basal patch buff yellow, extending to ¼. Hindwing with a row of white hair-scales in stead of costal bristles; basally on upperside with some yellowish white to buff yellow scales, similar to forewing underside. Female unknown.
Male genitalia. Capsule length 330-350 µm. Vinculum anteriorly slightly narrowed, truncate; lateral arms near gnathos with minute spines. Uncus with medial process pointed, with pair of lateral setae. Gnathos symmetrical, central element triangular, with wide apical angle; anterior processes present. Valva length 245-255 µm, basally broad, with parallel margins, posterior half suddenly narrowed towards short pointed tip, transverse bar of transtilla less than twice the length of sublateral process. Aedeagus 310-385 µm long, with ventral carina posteriorly ending in two ventrally curved processes; dorsal lobe at right side indistinct, a large lobe at left side, ventrally enlarged and strongly sclerotized. Vesica with three large cornuti: one long pointed (-135 µm) and two curved (respectively 85 and 60 µm); further a serrate cornutus lower in vesica, in addition to the group of needlelike and the small cornuti.
Immature stages and hostplant unknown.
Only known from Southwest France, in mediterranean region.
Adults collected in July and August.
This taxonomic description is based on van Nieukerken (1990).