Author: (Guenée, 1845)
Lettuce tortricid
Species Overview:
Adult: 15-19 mm wingspan; the pale yellowish brown general colouration of the forewing and the relatively conspicuous medio-dorsal blotch of light ground colour are characteristic.
Egg: ovate-lenticular, white, becoming coral-red two to three days after oviposition; deposited singly or in batches of two to six on the bracts of a flowerhead.
Larva: head black, or brown with region of stemmata and postero-lateral margin blackish; prothoracic plate brown; abdomen yellowish brown to reddish brown, paler ventrally; pinacula indistinct, more or less concolorous with integument; anal plate weakly sclerotized.
Pupa: yellowish brown; in a dense silken cocoon spun up in the soil or under surface litter.
Taxonomic Description:
Male:
Eucosma conterminana adult 1
Eucosma conterminana adult 2
External characters: 15-19 mm wingspan. Forewing without costal fold; ground colour pale ochreous-white, weakly suffused with brown; costa marked throughout with fine brownish strigulae; markings yellowish brown mixed or strigulated with darker brown; basal and sub-basal fasciae forming a diffuse, weakly strigulated basal patch, obsolescent costally and basally, its outer edge well defined dorsally, sharply angulated above middle; median fascia poorly defined costally, confluent with diffuse, slightly darker pre-tornal marking; a relatively large and conspicuous subtriangular blotch of light ground colour medio-dorsally; subterminal fascia indeterminate; ocellus subquadrate, edged laterally with pale golden or silvery metallic and containing two or three fragmented black dashes; cilia whitish grey irrorate with fuscous basally, ochreous-brown apically. Hindwing grey; cilia ochreous-white, with dark sub-basal and subapical lines (Bradley et al., 1979).
male genitalia E. conterminana
Genitalia: Uncus short, rounded apically; socius elongate, hairy; tuba analis weakly sclerotized; neck of valva with large concentration of bristles; ventral margin of valva concave; cucullus short, broad at apex. Aedeagus fairly short, with some short cornuti.
Female:
External characters: Similar to male.
female gen. E. conterminana
Genitalia: Lamella postvaginalis fairly short, irregularly convex caudally; ductus bursae short, cingulum well developed, swung; ductus seminalis originating in membranous portion of cingulum; corpus bursae with two well developed signa.
Biology:
Moths fly in July and August. Each female deposits a total of about 70-80 eggs, singly or in batches of two to six. Eggs can be found on the bracts of a flowerhead of the host plant. After 8-10 days, the eggs hatch and the young larva lives in the flowerheads, producing very little webbing and sometimes feeding partially exposed. Later it burrows into the developing seedheads and feeds on the ovaries. When fully fed the larva descends to the ground and constructs a cocoon in which it overwinters until the following spring. Pupation occurs in June, in a dense silken cocoon spun up in the soil or under surface litter (Bradley et al., 1979; Bovey, 1966).
Host plants:
Lactuca virosa, Lactuca serriola and cultivated lettuce, Lactuca scariola; Sonchus oleraceus
Damage:
Larvae can be found on cultivated lettuce. Young larvae live in the flowerheads, producing very little webbing and sometimes feeding partially exposed. Later they burrow into the developing seedheads and feed on the ovaries.
Distribution:
Europe; Baltic region to the Caucasus; Trans-Caucasus, Kazakhstan, Asia Minor, Central Asia to Southern Siberia and Southern Primo're; China, Mongolia.
Pheromone:
Pheromone unknown.
Parasitoids:
Glypta microcera Thoms. (Ichneumonidae)