Author: (Denis and Schiffermüller, 1775)
Species Overview:
Adult: 19-23 mm wingspan; forewings ochreous-white, irrorate with brown mixed with fuscous; markings brown, less distinct in females; hindwings greyish-brown.
Larva: up to 15 mm long; head dull brown, sometimes with yellowish mottling; prothoracic plate greenish or yellowish brown, edged with whitish anteriorly, a whitish medial sulcus, lateral margin marked with black or dark brown; abdomen dull reddish brown dorsally, yellowish white ventrally, a distinct narrow white dorsal line and a less distinct subdorsal line; pinacula large, white or yellowish white; peritreme of spiracles dark brown; anal plate yellowish; thoracic legs blackish brown [Tortricodes alternella larva].
Pupa: dark red-brown; in a tough cocoon of earth and dark brown silk in the ground or amongst debris on the ground.
Taxonomic Description:
Male:
Tortricodes alternella adult
Tortricodes alternella male
Tortricodes alternella males
External characters: Antenna fasciculate-ciliate. Costa of forewing almost straight. Forewing ground colour ochreous-white, sparsely irrorate and strigulated with brown mixed with fuscous, radial veins shaded with fuscous; basal area suffused with ochreous-brown or chestnut-brown; markings somewhat diffuse; sub-basal fascia black-brown, narrow, angulate at middle, obsolescent on dorsum; median fascia broad, rather oblique, inner margin well-defined, sinuous; pre-apical spot wedge-shaped; cilia grey. Hindwing greyish brown, apex and margins infuscate; cilia paler (Bradley et al., 1973).
male genitalia T. alternella
Genitalia: Uncus strong, spined, with small basal lobes devoid any spines; socius well developed; gnathos strong, with wedge-shaped terminal plate; vinculum strong. Valva broad anteriorly, with strongly expanding dorsal portion of basal part of costa; sacculus heavily sclerotized, with subdorsal fold medially; a cup-shaped sclerite in basal corner of valva; transtilla membranous with slender sclerotized rods fused with costa; juxta fused with caulis; aedeagus thin, long and highly curved, armed with pair of thin processes situated laterally.
Female:
Tortricodes alternella female 1
Tortricodes alternella female 2
External characters: Antenna sparsely ciliate. Costa of forewing more strongly curved than in male; ground colour extensively suffused with fuscous, markings as in male, but less distinct. Hindwing fuscous-grey; cilia paler.
female genitalia T. alternella
Genitalia: Strongly sclerotized; sterigma semicircular with membranous ostium area; antrum distinctly sclerotized, curved; ductus seminalis subdorsal; signum weak.
Biology:
Adults fly in February or March, later in more northerly areas. The males fly rapidly in sunny weather, the females usually remaining at rest on tree trunks, but both sexes are active at night (Bradley et al., 1973).
Larvae feed in May and June on the leaves of the host plant, each larva sheltered by a folded leaf edge or within spun leaves. Full-grown larvae pupate in tough, silken cocoons formed in the soil or amongst debris on the ground, remaining in situ throughout the winter (Alford, 1995).
Host plants:
Hornbeam (Carpinus betulus), oak (Quercus), birch (Betula), hawthorn (Crataegus), hazel (Corylus avellana), linden (Tilia) and blackthorn (Prunus spinosa).
Minor infestations of this species sometimes occur on ornamental trees growing in the vicinity of mixed deciduous woodlands.
Damage:
Larvae of Tortricodes alternella attack the foliage of various trees, each larva sheltered by a folded leaf edge or within spun leaves. They can sometimes be found on ornamental trees growing in the vicinity of mixed deciduous woodlands, but are not a serious pest (Alford, 1995).
Distribution:
Europe from England and Sweden to the Mediterranean Sea and Western Russia.
Pheromone:
Pheromone unknown.