Author: (Müller, 1764)
Mountain-ash tortricid
Species Overview:
Adult: 19-30 mm wingspan (females larger than males); forewing ground colour pale yellowish brown, weakly reticulate with light brown; markings olive brown. Hindwing dark grey.
Larva: 35-40 mm long; head dark brown or black; prothoracic plate brown, postero-lateral margins black, anterior margin straight, edged with whitish; abdomen greyish dark green; pinacula small, greenish white; thoracic legs black; anal plate yellowish brown.
Pupa: brownish black; second tergite with two rows of spines.
Taxonomic Description:
Male:
C. hebenstreitella male
C. hebenstreitella male 2
External characters: 19-25 mm wingspan; forewing with short costal fold from above base to near middle. Ground colour pale yellowish brown, weakly reticulate with light brown; markings olive brown; basal fasciae complete, outer margin oblique, slightly sinuous; outer margin of median fascia indented below costa, inner margin usually unbroken. In some specimens the median fascia is completely broken below the costa. Hindwing dark grey; cilia paler (Bradley et al., 1973).
male gen. C. hebenstreitella
aedeagus C. hebenstreitella
Genitalia: Tegumen narrowed posteriorly as viewed antero-dorsally, width at dorso-posterior end one-half that at base; lateral side distinctly convex as viewed antero-dorsally. Uncus short, narrow, nearly straight, and parallel-sided; apex as wide as subbase; ventral surface of apical third with dense, fine, short, and forked or multibranched setae. Socius well developed, directed ventro-posteriorly, shorter than uncus; anterior margin deeply notched at midlength; dorsal area from notch to apex with numerous upcurved long setae. Gnathos smooth, C-shaped as viewed laterally; straight length between base and apex slightly longer than socius, but shorter than uncus. Transtilla smooth. Aedeagus nearly straight, moderately sclerotized; left side of distal half distinctly narrowed ventro-apically; ventral apical angle round and smooth without apical spine; right side expanded toward apex, truncate, bearing short conical spine at dorsal apical angle; aedeagal surface with a few ultramicroscopic spicules; cornuti lanceolate. Valva subquadrate, slightly longer than basal width. Sacculus surface smooth; dorsal margin not raised; ventral margin sinuate; distal end not distinctly raised (Dang, 1992).
Female:
C. hebenstreitella female
C. hebenstreitella female 2
External characters: 24-30 mm wingspan; forewing without costal fold, apex more produced. Reticulation slightly heavier and median fascia of the forewing stronger than in male. Hindwing with apical cilia often tinged with yellow.
female gen. C. hebenstreitella
Genitalia: Sterigma with elongate-subtriangular lateral portions, deeply concave medially, antrum weakly sclerotized; ductus bursae very long, thin, with very long cestum, signum long.
Variation:
Slight variation of the forewing ground colour occurs in both sexes and some specimens, especially females, have a distinct yellowish appearance. In the markings, the greatest variation is found in the median fascia, which may be completely broken below the costa.
Taxonomic note:
Dang, 1992, believes that Choristoneura adumbratana and Choristoneura hebenstreitella are conspecific. Minor differences in the shape of the socius and the degree of spiculation on the aedeagus probably represent intraspecific variation. However, the species are presently recognized as two distinct species.
Biology:
The species is univoltine. Moths occur in June and July. Eggs are deposited on the leaves of the food plant. Larvae feed briefly before hibernation, completing their development in the spring. Hibernation of these first instar larvae occurs in a spun hibernaculum. Pupation occurs in late May and June, in the larval habitation.
Host plants:
Betula, Corylus, Malus, Prunus, Pyrus, Quercus, Sambucus, Sorbus, Ulmus, Vaccinium.
Damage:
Larvae feed on foliage and live in open leafbuds and rolled leaves, they also damage flowers and ovaries. Apple, pear and plum are among the host plants, but Choristoneura hebenstreitella is not an important fruit pest (Alford, 1984).
Distribution:
Europe. Records from Asia are doubtful.
Pheromone:
Pheromone unknown.
Attractantia:
Z 11-14OH : 97
E 11-14OH : 3 (Frérot et al., 1979b)
or
Z 11-14Al : 1
Z 11-14OH : 1 (Booij and Voerman, 1985)
Parasitoids:
List of pupal parasitoids provided by Butkevich, 1986 (publication not available).