Author: Komai, 1980
Species Overview:
Adult: Forewing greyish brown, mottled with pale ochreous, with pale ochreous costal strigulae, some emitting long, oblique leaden-metallic streaks; dorsal patch yellowish white, divided by some dark greyish lines; ocellus pale ochreous, margined laterally by two vertical leaden-metallic lines; apex dark brown. Hindwing dark greyish brown, paler towards base.
Larva: 8-9 mm long; head yellowish brown, with dark pigmentation in region of stemmata. Body pale yellow. Prothoracic shield, pinacula of L setae on prothorax, thoracic legs and anal shield pale dark brown. Pinacula and peritreme of spiracles distinct, dark. Spinules of integument darker than body colour. Setae pale [Pseudopammene fagivora larva ].
Pupa: 5.5 x 1.5 mm; uniformly yellowish brown. A2-7 with two rows of spines (caudal row weak); A8-10 with one row of spines.
Taxonomic Description:
Male:
External characters: Wingspan 11-12.5 mm. Head, palpus and thorax dark brown, mixed with pale ochreous. Abdomen brownish grey, ventral side pale ochreous. Forewing greyish brown, mottled with pale ochreous; on costa a series of oblique yellowish white strigulae, four or five indistinct pairs before middle, six distinct pairs from middle to apex, of these ultimate two single and less oblique, those at 2/5 and 2/3 emitting long, oblique leaden-metallic streaks, the other strigulae each terminating beneath in a leaden-metallic spot or short line; interstices between strigulae dark brown; dorsal patch from middle, oblique yellowish white streak, divided by some dark greyish lines, reaching 1/2 across wing thence continuing a leaden-metallic streak from costal strigula at 2/5, edged anteriorly and posteriorly by dark shade; on upper angle of cell an irregular black dot; ocelloid patch pale ochreous, margined laterally by two vertical leaden-metallic lines, inner edge of this patch almost touching leaden-metallic streak from costal strigula at 2/3, sometimes containing some black dashes; between outer edge of ocelloid patch and termen two or three black dots; apex dark brown; cilia pale greyish brown with a greyish brown basal line; cilia of notch on termen with white tips. Hindwing dark greyish brown, paler towards base; veins dark brown; cilia ochreous, white with a greyish brown basal line (Komai, 1980).
male genitalia P. fagivora
Genitalia: Tegumen broad, with rather pointed top. Sclerites of tuba analis weak, lateral sclerites linking it with pedunculus slender, sclerotic. Valva with a small basal opening; cucullus large. Aedeagus slender, little curved, gradually narrowed, with group of short, deciduous cornuti in vesica.
Female:
Pseudopammene fagivora female
External characters: Similar to male.
female genitalia P. fagivora
Genitalia: Ovipositor somewhat elongate; sterigma slender, postvaginal plate with distinctly sclerotized lateral edge, antevaginal sclerite not developed; ostium bursae protected by ventro-lateral sclerite; cestum anterior, accompanied by weak postmedian sclerites; ductus seminalis long, originating at cestum, laterally; corpus bursae with two horn-shaped signa. Subgenital sternite small, deeply incised distally.
Biology:
The female of P. fagivora has eight ovarioles, each containing more than 20 eggs, and the fecundity of this species is estimated to be more than 160. Females lay their eggs individually and randomly on the cupule surface. The larvae bore into the cupule and feed on the ovule in the seed. A pinhole is bored into cupule and seeds. The infested seed is filled with frass. Larvae are found in seeds from early June to late July, and the seedfall caused by P. fagivora starts in mid July and continues until October. This indicates that some of the seeds infested by this insect remain on the tree until fall. The mature larvae escape from the seed and drop to the ground; they pupate within cocoons in the litter or in the soil, and overwinter in the pupal stage. According to Komai, 1980, adults emerge from late April to May; according to Igarashi and Kamata, 1997, adults are observed from mid May to early July. The long period of infestation by P. fagivora appears to be the result of the great variance in the time of adult emergence.
The species is univoltine (Komai, 1980).
Host plants:
Fagus crenata
Damage:
infested beech nut
Pseudopammene fagivora is one of the most abundant insect pests of Japanese beech, Fagus crenata, in northern Honshu, and seems to be the most important insect species related to its seed survival.
Larvae bore into the nuts.
Distribution:
Japan (Honshu).
Pheromone:
Pheromone unknown.