Author: Komai, 1979
Species Overview:
Adult: 11-14 mm wingspan; forewing greyish fuscous, irrorated by white-tipped scales (especially on outer half); costa with seven whitish interspaces between costal strigulae, from first, second, third and fifth interspaces arise dark leaden metallic lines (the first two obscure); dorsal patch hardly discernible; ocellus large, edged laterally with leaden metallic streaks and containing six or more black dashes. Hindwing fuscous, becoming paler basally; in males strongly concave in lower part of termen.
Pupa: in a cocoon directly under the surface of the fruit.
Taxonomic Description:
Male:
G. dimorpha adult
G. dimorpha male
External characters: 11-14 mm wingspan. Head, antenna and labial palpus greyish fuscous. Thorax greyish fuscous, tips of scales pale ochreous. Forewing rather broad, elongate-triangular, termen slightly notched below apex. Ground colour greyish fuscous, irrorated by white-tipped scales, the irroration especially pronounced on outer half; costa with seven whitish interspaces between fuscous costal strigulae, from 1/3 to apex, the first four interspaces in pairs, followed by three single; from first, second, third and fifth costal strigulae arise dark leaden metallic lines, the first two obscure, the third almost reaching to posterior edge of ocellus, the fourth extending to notch on termen; dorsal patch only indicated by scarcely discernible lines; ocellus large, edged laterally with leaden metallic streaks and containing six or more black dashes, the third or fourth dash from tornus being the longest and breaking posterior edge of ocelloid patch; a small pale spot on notch of termen; cilia shiny grey, with a blackish basal line. Hindwing fuscous, becoming paler basally; cilia shiny greyish ochreous, with a dark basal line; in male lower part of termen strongly concave, cilia between vein M and vein 1A+2A composed of short spade-like scales (Komai, 1979).
male genitalia G. dimorpha
Genitalia: Tegumen rather broad with pointed top. Valva rather narrow, broadly grooved in area of neck, its dorsal margin (costa) gently arced; cucullus oval. Aedeagus strongly curved, broad in basal half; cornuti a series of filiform thorns.
Female:
G. dimorpha female
External characters: Forewing markings and colouration similar to male.
female genitalia G. dimorpha
Genitalia: Sterigma large and stout, its cephalic margin strongly concave. Seventh sternite with convex caudal margin. Ductus bursae membranous, with an oval sclerite on position adjacent to corpus bursae. Inception of ductus seminalis situated caudally on corpus bursae; signa large, horn-shaped.
Biology:
Females lay their eggs singly on the surface of the fruit. Larvae bore directly into the fruit. After being fully fed, non-diapause larvae make spindle-shaped slits on the skin from the inside of the fruit, and then spin cocoons on the inner-surface of the cut fractions. These fractions shrink due to drying and become dislodged from the original fruit-body. Diapause larvae emerge from the fruit and spin cocoons on the ground.
Moths fly in April and June and again in July and August.
Host plants:
Japanese plum (Prunus salicina) , Japanese quince (Chaenomeles speciosa), and dwarf quince (Chaenomeles speciosa).
Damage:
Larvae feed directly under the surface of fruits of Japanese quince and plum.
Distribution:
Japan and Korea.
Pheromone:
Pheromone unknown.
Grapholita molesta (Busck)
The species resembles Grapholita molesta, but the latter inhabits the lowlands, whereas Grapholita dimorpha is found in mountainous areas, and it is possible that distribution of these species is not sympatric, although supporting data are insufficient.