Author: (Scopoli, 1763)
Species Overview:
Adult: 15-19 mm wingspan. A distinctive species, having well-defined forewing markings which normally contrast with the silvery white ground colour.
Larva: head black; prothoracic plate dark brown or black; abdomen dull yellowish green to brownish or greyish green; pinacula paler than integument, inconspicuous; anal plate dull green; thoracic legs dark brown.
Pupa: Light brown; thorax darker dorsally; in a flimsy cocoon in the larval habitation or spun up among leaves on the ground.
Taxonomic Description:
Male:
Celypha rivulana adults
External characters: 15-19 mm wingspan. Forewing ground colour silvery white, striated with ochreous-brown; markings well defined except basal fascia, ferruginous-brown or chocolate-brown, variably sprinkled and edged with black; median fascia with inner margin irregular, slightly concave, outer irregular, with a strong projection in middle, emarginate above and below; pre-tornal marking subtriangular to ovate; subterminal fascia usually fragmented or interrupted at costa; apical spot variable; cilia pale ochreous-white or cream-white, marked with fuscous opposite apical, terminal and pre-tornal markings; a distinct fuscous sub-basal line. Hindwing grey; cilia concolorous on inner margin, becoming paler along termen, sometimes greyish at apex, a dark grey sub-basal line (Bradley et al., 1979).
male genitalia C. rivulana
sacculus C. rivulana
Genitalia: Valva with narrow cucullus; sacculus broad, with distal process on which a tuft of setae is situated; another tuft of longer setae is situated on ventral margin near distal process; margin of sacculus covered with short bristles. Vesica of aedeagus without cornuti. Socii fused with tegumen. Uncus narrow. Gnathos thin; tuba analis large.
Female:
External characters: Similar to male.
female genitalia C. rivulana
Genitalia: Sterigma spiculate, median part incised, lateral parts fairly large, rounded posteriorly. Corpus bursae without signum.
Variation:
Considerable minor variation occurs in the colouration and development of the forewing markings which may be warm reddish brown in specimens having the ferruginous colouration very strong, or dark chocolate- or fuscous-brown contrasting with the silvery-white ground colour. Rarely, specimens occur in which the ground colour is heavily suffused with grey, or the markings are very pale with a slight olive tint and do not contrast sharply with the ground colour (Bradley et al., 1979).
Biology:
In Europe, moths occur July and August. Larvae are polyphagous, feeding in the flowers and terminal shoots of their hosts. Pupation occurs in a flimsy cocoon in the larval habitation or spun up amongst leaf litter on the ground.
Host plants:
Larvae usually feed on herbaceous plants including Filipendula ulmaria, Genista, Orchis, Hieracium, Fragaria (strawberry), Lotus, Medicago, Plantago, Galium and Scabiosa. Also on Vaccinium (billberry, bog whortle berry, cowberry), Rubus (raspberry, dewberry), Ribes, Alnus and Betula.
Damage:
On herbaceous plants, larvae feed in the flowers and terminal shoots, often eating into the stem and causing flowers to wilt.
Distribution:
Europe to Siberia, Mongolia, North-Western China and Korea.
Pheromone:
Pheromone unknown.