Author: (Meyrick, 1912)
Greenish chestnut moth
Species Overview:
Adult: 17-21 mm wingspan; forewings dull olive-greenish, mixed or strigulated with dark fuscous; a large blackish blotch extending along costa; costa with two oblique leaden metallic strigae and a blackish striga between them; a leaden-metallic streak close before termen in middle, preceded by a blotch of blackish suffusion at dorsum. Males with costal fold. Antenna with notch close above base. Hindwings fuscous.
Taxonomic Description:
Male:
Eucoenogenes aestuosa adult
External characters: 17-21mm wingspan. Head and thorax olive-greenish marked with dark fuscous. Palpi ochreous-whitish, second joint with apical bar and two spots dark fuscous. Antenna with notch close above base. Forewings elongate, posteriorly slightly dilated, costa gently arced, with rather narrow fold extending from base to beyond middle, apex obtuse, termen sinuate, somewhat oblique; dull olive-greenish, mixed or strigulated with dark fuscous; a large blackish blotch extending along costa, from base to 3/5 and reaching 3/4 across wing, lower edge with triangular emargination beneath middle of wing edged with white anteriorly, posterior edge rather oblique, with two acute projections, edged with leaden-metallic; costa posteriorly black with pairs of whitish strigulae, giving rise to two oblique leaden metallic strigae and a blackish striga between them; a leaden-metallic streak close before termen in middle, preceded by a blotch of blackish suffusion; cilia olive-greenish, mixed with dark-fuscous at apex and upper part of termen. Hindwings fuscous, veins and termen dark fuscous; cilia fuscous.
male genitalia E. aestuosa
Genitalia: Uncus broad, short, bifid terminally; socius drooping, hairy; tuba analis provided with lateral sclerites. Valva broad anteriorly; neck distinct, spined or bristled; angle of sacculus well developed, provided with hairy lobe from below which strong spines and bristles extend; posterior edge of basal cavity bristled; cucullus spined, with marginal spines strong but short. Aedeagus simple, long; caulis fairly long; cornuti deciduous.
Female:
External characters: as male; without costal fold.
female genitalia E. aestuosa
detail fem. gen. E. aestuosa
Genitalia: Sterigma concave, with short lamella antevaginalis and large lamella postvaginalis, membranous at ostium bursae, with dorsal wall produced anteriorly; ostium protected by very weak, short sclerite; cingulum very large, situated in antero-median part of the ductus bursae; ductus seminalis situated anteriorly. Corpus bursae pyriform, with two strong signa.
Biology:
In Hokkaido (Japan) there is one generation yearly, in the south of Japan there are more generations yearly. Hibernation occurs in the larval stage; larvae feed in seeds of Castanea .
Host plants:
Castanea crenata.
Damage:
This species is a pest of chestnut in Japan; larvae bore into the nuts.
Distribution:
Japan, Korea, Southern China (North Yunnan), Northern India.
Pheromone:
Pheromone unknown.