Author: (Linnaeus, 1761)
Flat tortricid
Species Overview:
Adult: 15-12 mm wingspan; forewings greyish-white, greyish-, yellowish- or reddish-brown, with a more-or-less conspicuous dark costal blotch; anterior margin of forewing moderately rough-scaled; hindwings grey. A very variable species.
Larva: head brownish yellow or brownish green; prothoracic plate similar to head, or shining green, marked with blackish brown postero-laterally; abdomen light green or yellowish green, sometimes tinged with grey, darker dorsally; pinacula concolorous with integument; anal plate green, marked with brown; anal comb yellowish; thoracic legs light greenish brown [Acleris schalleriana larva].
Pupa: 8-9 mm long; light brown.
Taxonomic Description:
Male:
Acleris schalleriana adult
Acleris schalleriana adults 1
Acleris schalleriana adults 2
External characters: 15-12 mm wingspan. Labial palpus and head whitish; thorax whitish-grey; abdomen greyish. Forewing costa strongly curved basally, then straight or slightly arced outwards; apex short, delicately rounded; termen straight, hardly oblique. Forewing markings variable.
A common 'form': forewing ground colour greyish-white to cream, sparsely sprinkled with violet-brown scales, especially along termen, sometimes mixed with ochreous in distal area, a raised ochreous mixed with violet-brown discocellular scale-tuft near apex of costal blotch and contiguous with its inner margin, a small violet-brown mixed with white scale-tuft dorsad of submedian fold at about one-third; markings reduced, plumbeous with violet-brown and black admixture; basal and sub-basal fasciae developed on costa, outer margin of sub-basal indicated by sparse violet-brown scales; costal blotch well developed, triangular, extending to near apex; an incomplete line of raised scales along inner margin of costal blotch; cilia grey, apices paler, with a dark grey basal line.
Forewing ground colour in other forms: yellowish brown, light reddish brown or greyish brown (see 'variation').
Hindwing grey, infuscate distally; cilia paler, with a dark sub-basal line (after Razowski, 1984; Bradley et al., 1973).
male genitalia A. schalleriana
Genitalia: Tegumen delicate, slightly concave in middle posteriorly; socii large, erect, elongate, slightly tapering terminally, well sclerotized anteriorly, on broad short bases; tuba analis slender; valva elongate; sacculus rather slender, broad anteriorly with large finger-like processes in middle of ventral edge, broadening beyond this process (anterior edge almost parallel to edge of process); spined termination large. Aedeagus rather short, slender; 11-15 slender cornuti (2 or 3 of them are long) present in vesica.
Female:
External characters: Similar to male.
female gen. A. schalleriana
Genitalia: Papillae analis slender; apophyses long; sterigma with large posterior prominence and slender, delicately curved, pointed apically, anterior projections; antrum short, rather broad; ductus bursae broad, narrowing terminally; corpus bursae with elongate, dentate, signum.
Variation:
In the form as described above, the forewing ground colour varies from whitish-grey to cream-white. A form occurs with the costal blotch fractured, the sub-apical spot sometimes being completely separated, the whitish ground colour showing through. A further form occurs with rather distinct yellowish brown or light reddish brown ground colour and a moderately strong costal blotch and in another, the blotch is obscure and the wing is almost unicolorous reddish brown. In some populations the ground colour is predominantly greyish-brown or distinctly grey, with the markings variably developed but never strong and well-defined (after Bradley et al., 1973).
Biology:
Adults appear from late August or September onwards, hibernating during the winter and reappearing in the following spring. Eggs are laid on the host plant, hatching in late May or June. The larvae then feed within spun leaves until August. Pupation occurs in the larval habitation, in August and September (Alford, 1995; Bradley et al., 1973).
Host plants:
Viburnum, Rhododendron simsii.
Damage:
Larvae are associated with Viburnum, infestations sometimes occurring on ornamental shrubs. Infested shoots are distorted but infestations are of little importance (Alford, 1995).
Distribution:
Europe to Central Asia except Southern Italy and Greece; in North America this species is represented by the subspecies Acleris schalleriana viburnana Clemens.
Pheromone:
Pheromone unknown.
Parasitoids:
Pseudoperichaeta nigrolineata (Walker) (Tachinidae)