Author: Diakonoff, 1950
Adult: wingspan males 33-40 mm, females 48-59 mm; forewings purplish-black with pale yellow markings consisting of a red streak from base of wing to terminal patch, a narrow red (males) or orange (females) terminal patch, very narrow oblique streaks on costa, and fine pale yellow dots, arranged in regular rows among the veins. Hindwings yellowish orange with black markings, apical quarter of wing black in males.
Larva: 27-31mm long; head and thoracic shield dark brown, reddish brown or yellowish brown; thoracic legs, anal shield and body paler than the head colour; pinacula dark coloured, very conspicuous; anal fork well developed. Seta SD1 on the same pinaculum as seta SD2 on abdominal segments 1-8 [Cerace xanthocosma larva].
Pupa: about 28mm long, yellowish green, basal area of lateral and dorsal setae black-brown; no rows of spines present on the dorsum of the abdominal segments [Cerace xanthocosma pupa].
Cerace xanthocosma male
External characters: Head yellow, tuft around and between the base of antenna black; antenna dark brownish-grey, with black bands; collar yellow; thorax purplish black with yellow dots; metathorax dark brown with a pair of yellowish orange tufts of long hairs at the sides; abdomen yellowish orange, dorsal halves of segments with black bands along posterior part; legs yellowish orange, tarsi black; posterior halves of basal segments and apical rings of those segments yellowish orange. Forewing black, tinged with purple. Markings consisting of a red streak from base of wing to terminal patch, with a narrow branch along basal two-fifths of the anal vein, a narrow red terminal patch, very narrow oblique streaks on costa and fine pale yellow dots, arranged in regular rows among the veins. Leaden, metallic, scales are present on the red streak and on terminal patch. Cilia black with yellowish orange scales at termen. Hindwing yellowish orange with black markings, anal half densely covered with large rounded blotches and dots reaching the lower edge of the median cell, connected with each other and arranged in diverging rows parallel with the anal veins; apical quarter of wing black. Cilia bright orange-yellow, shining, with a few black dots around apex (Diakonoff, 1950a; Diakonoff, 1970; Yasuda, 1975b).
male gen. Cerace xanthocosma
Genitalia: Tegumen strong and broad; uncus robust with a broad base and a dilated top, with two large patches of bristles; gnathos rather long with slender arms and a strong terminal hook; socii elongate, almost as long as gnathos. Valva elongate, rather slender, gradually curved, with dense bristles; costa broad; sacculus rather weak, narrow; transtilla membranous. Aedeagus short, stout, tubular, slightly curved; orifice oblique. Cornuti absent.
Cerace xanthocosma female
External characters: Forewing faded purple-black, black along costa and often along the base; a pale reddish streak from base to terminal patch, interrupted by rows of yellow dots; costal fasciae broader than in male, dots more conspicuous; terminal patch yellowish-orange. Hindwing rather dark yellowish orange, mostly tinged ochreous; markings dark greyish black; irregular rounded blotches and dots, more or less connected each other, in diverging rows.
female gen. Cerace xanthocosma
Genitalia: Distal portion of sterigma with weak concavities and large proximal part deeply incised ventrally and fused with swung antrum, the latter distinctly sclerotized except for broad anterior portion from which extends ductus seminalis; signum at base of ductus bursae, in form of rather large ovate sclerite folded transversely, provided with strong dents. Ventral arms of anterior apophyses form a sclerotized transverse band above the ostium, and not as usually is the case in Tortricinae, below the ostium 7th sternite strongly sclerotized, ventrite with deep emargination in middle.
Cerace xanthocosma is a bivoltine species. The larvae hibernate in the folded old leaves of the lower parts of the stem of broad-leaved evergreen trees. Larvae commence feeding in the next spring, at about the time when the buds of the host plant are expanding. The feeding may continue during the winter when the weather is mild. In April the larvae fold the leaves eating the foliage of the current year. They are full-grown by late May, and then pupate The adults emerge in June and July and eggs are deposited on deciduous trees. Adults of the second generation emerge in early September.
Abies veitchii, Acer palmatum, Cinnamomum spp., Clethra barbinervis, Ilex pedunculosa, Lyonia ovalifolia var. elliptica, Magnolia grandiflora, Picea jezoensis, Pieris japonica, Prunus spp., Punica granatum, Quercus. It has also been recorded from tea (Camellia) in Japan.
Larvae feed on the leaves of the food plant. It has been recorded from tea in Japan, but is of no economic importance.
Japan: Shikoku, Kyushu, Honshu; Russia: S. Sakhalin.
Pseudoperichaeta insidiosa Robineau-Desvoidy (Tachinidae)
Zenilla libatrix Panzer (Tachinidae)