Ptycholoma Stephens
Type species: lecheana Linnaeus
DIAGNOSIS
External characters:
Venation:
venation Ptycholoma lecheana
Forewing: All veins are separate.
Hindwing: M 3-CuA 1 originate separately, from one point or very shortly stalked.
Forewing shape and markings:
Ptycholoma lecheana males; P. lecheana circumclusana male; Ptycholoma lecheana female 2; Ptycholoma imitator adult
Forewing elongate, in males dilated posteriorly, costa arced outwards basally, then straight. Costa more gently arced in females. Males with narrow costal fold. Markings variable.
Sexual dimorphism:
Sexual dimorphism is expressed in the shape of the forewing. Females without costal fold.
Genitalia:
Male:
male genitalia P. imitator ; male genitalia P. lecheana
Gnathos simple, without spines. Valva in terminal part strongly elongate, with long area of folds of disc and small sub-basal pulvinus; sacculus terminating in a thorn.
Transtilla slender medially, with lateral portions broad dentate dorsally. Coecum penis rather short, with large sclerites of base of caulis; cornuti very short, deciduous.
Female:
female genitalia P. imitator ; female gen. P. lecheana
Distal part of sterigma deeply concave transversely, median part also concave, anterior portion funnel-shaped, fused with antrum; the latter provided with indistinct internal sclerite, extending anteriorly; ductus seminalis dorsal, from antrum area; no cestum present in ductus bursae; signum with large basal plate and proportionally small dagger.
Early stages:
Larvae are greenish in colour. Chaetotaxy: SV group on abdominal segments 1, 2 and 7 bisetose.
Biology:
One or two (in Japan) generations yearly; hibernation in larval stage; larvae polyphagous on deciduous trees and conifers.
Distribution:
The genus occurs in the Palaearctic and Nearctic Regions.