Three-spot grass-veneer (Glaucocharis triochellaris) and dull gray grass-veneer (Glaucocharis plumbofascialis) from Japan

NEWS - Three-spot grass-veneer (Glaucocharis triochellaris Matsui, Yagi & Hirowatari sp. nov.) and dull gray grass-veneer (Glaucocharis plumbofascialis Matsui, Yagi & Hirowatari sp. nov.) from the Ogasawara Islands of Japan with adult, male and female genitalia and molecular phylogenetic analysis revealed a sister relationship between the two new species and the monophyly of Glaucocharis Meyrick 1938.

G. triocellaris is easily distinguished from the other species by distinctive morphological features, such as three black spots on the margin, each enclosing a silvery white spot in the middle of the forewing; a valve with a strong hook-shaped protrusion emerging from the middle of the ventral valve margin and a phallus with hook-shaped apical spines curved ventrally on the male genitalia; and a circular spinous antevaginal lamella on the female genitalia.

Although larvae were not found, adults emerged from various Bryopsida species collected on Hahajima Island. The larvae make a cocoon using leaf fragments of Bryopsida spp. and then pupate inside it. The pupal exuviae are not visible from the cocoon after emergence.

The mature larvae fly during the day and night, but most specimens were collected by light traps at night. This species is considered multivoltine. Distribution in the Ogasawara Islands (Chichijima and Hahajima Islands).

G. plumbofascialis is easily distinguished from other species by distinctive morphological characters, such as the plumbeous postmedial and submarginal fasciae that are sharply angled outward at M1 on the forewings; the cullular valve with highly sclerotized branches and the phallus with sheath-like apical spines on the male genitalia; and rectangular lamellae like the postvaginal and antevaginal plates on the female genitalia.

Similar to G. triocellaris, researchers observed some adults visiting the flowers of Bidens pilosa var. radiata (Sch. Bip.) J.A. Schmidtthe during the day. Many adults gather around Euonymus boninensis Koidz at dusk. All individuals are males. Distribution in the Ogasawara Islands (Chichijima, Anijima, Otôtojima, Mukohjima, and Hahajima Islands).

DESCRIPTION

Glaucocharis triochellaris

Head. Fronts brown, rounded. Vertex brown, lateral sides ocherous. Maxillary palpus almost as long as compound eye, outer side ocherous basally, pale ocherous apically, inner side white. Labial palpus about 1.6 times longer than compound eye; first palpomere ocherous dorsally, white ventrally; second palpomere with apically expanded scale tuft, ocherous on outer side, white on inner side; third palpomere white basally, brown apically, apex pointed. Maxillary and labial palpi strongly upturned in resting posture. Antennae about 3/4 of forewing length, brown, ciliate in male, filiform in female; scape brown dorsally, white ventrally. Proboscis covered with white scales basally.

Thorax and legs. thorax brown dorsally, white ventrally. Patagium brown, lateral sides ocherous. ocherous tegula on inner half and whitish silver on outer half. Foreleg femur white; tibia white, dorsal side gray apically; tarsus gray. Midleg femur white; tibia gray dorsally, white ventrally, inner and outer spurs gray, almost of equal length; tarsus gray. Hindleg femur white; tibia gray dorsally, white ventrally, mid and hind spurs gray, almost the same length; tarsus gray.

Wings. Forewing length 3.2–4.5 mm (mean 3.9 mm, n = 10). Forewing ground color dark brown, tinged with reddish yellow from wing base to medial fascia and apical region; all fasciae and apical markings silvery white with blue luster; basal fascia represented by two oval spots; antemedial and medial fasciae almost straight; postmedial fascia oblique outwardly, ending near termen; submarginal fascia oblique outwardly, disappearing at r5; apical mark represented by a short stripe vertical to costa; three marginal spots black, comma-shaped, connected, each enclosing silvery-white dot medially; marginal spots surrounded by yellow area with irregular black scaling along inner margin; subapical indentation of termen deep with white cilia; rest of cilia dark brown. Hindwing ground color dark brown, medial area white, with a narrow white band along CuA2 in male; Cilia Brown.

Wing venation (n = 3). Forewing Sc concurrent with r1 at 2/3 of length, then diverging as short spur distally; r2 separate; r3 stalked with r4 at 3/5 distance from cell; r5, M1, M2, and M3 separate, almost parallel; CuA1 close to M3 basally; CuA2 distant from CuA1; A1+2 strong; A3 weak, not looped; cell opened. Hind wing Sc+r1stalked with rs at 4/5 of length; M1, M2, M3, CuA1, and CuA2 separate; CuP, A1+2 and A3 are well-marked. Female with three frenular bristles.

Abdomen. Dorsal side dark brown, ventral side pale brown, 1st and 2nd sternites tinged white. tympanal organs: bulla tympani small, bean-shaped, anterior margin convex; fornix tympani narrow, recessed under venula prima; tympanic pons absent; venule prima developed, extending to about 2/3 from posterior margin of 2nd sternite. Male 8th tergite with a triangular sclerotization on anterior half. Male 8th sternite with a long trapezoid sclerotization, posterior margin concaved medially. Female eighth sternite wrinkled laterally.

Male genitalia (n = 6). uncus almost straight, apex pointed. gnathos beak-shaped, dorsal side sparsely denticulate, apex pointed and curved dorsally. long tegument, dorso- and ventrolateral margins forming sclerotized ridges; socii finger-shaped with six petaloid lobes apically. Valva slender, curved ventrally, with sturdy hook-shaped projection emerging from middle of ventral margin; cucullus slightly enlarging distally, truncated apically, with long setae dorsally; costal margin sclerotized, with thumb-like costal arm at base; sacculus triangular, ventral side setose. Juxta oval, dorsal margin strongly concave medially. Saccus short, rounded. Phallus narrowing posteriorly, distal end pointed and slightly curved ventrally; apical thorn large, hook-shaped, strongly sclerotized, curved ventrally; cornuti absent; ejaculatory duct connected at anterior end of phallus.

Female genitalia (n = 6). Papillae anales ovate, membranous, weakly fused. Anterior and posterior apophyses thin and straight, almost equal in length. Lamella postvaginalis a square plate. Lamella antevaginalis a circular spinose sclerotization, covering ostium. Membranous ductus bursae, almost as long as corpus bursae. The seminal duct is located at anterior 2/3 of the ductus bursae. Corpus bursae membranous, anterior half slightly swollen, posterior half granulate; signa absent.

Glaucocharis plumbofascialis

Head. Fronts pale ocherous, anterior margin white. Vertex brown, lateral sides ocherous. Maxillary palpus about 0.7 times longer than compound eye, outer side ocherous basally, pale ocherous apically, inner side white. Labial palpus about 1.6 times longer than compound eye; first palpomere ocherous dorsally, white ventrally; second palpomere with apically expanded scale tuft, ocherous on outer side, white on inner side; third palpomere pale ocherous, with pointed apex. Maxillary and labial palpi strongly upturned in resting posture. Antennae about 3/4 of forewing length, brown, ciliate in male, filiform in female; scape brown dorsally, white ventrally. Proboscis covered with white scales basally.

Thorax and legs. thorax brown dorsally, white ventrally. Patagium and tegula brown. Foreleg entirely white. Midleg femur white, ventral side basally gray; tibia gray dorsally, cream white ventrally, inner and outer spurs cream white, inner one slightly longer than outer one; tarsus cream white. Hindleg femur cream white, ventral side black at 2/3 from base; tibia gray dorsally except basal 1/3, cream white ventrally, mid and hind spurs gray, respective inner and outer spurs almost the same length; tarsus cream white.

Wings. Forewing length 3.1–3.9 mm (mean 3.4 mm, n = 10). Forewing ground color dark brown, outer area of medial fascia ocherous; basal, antemedial, medial, postmedial, and submarginal fasciae plumbeous with blue luster, both sides of each fascia margined with black lines; basal, antemedial, and medial fasciae obscure, angled outwards at M1; postmedial and submarginal fasciae distinct, sharply angled outwards at M1, whitish near costa; discal spot ocherous, oval, located at inner angle of medial fascia; two marginal spots irregular, black, located at M3 and CuA2 on termen; subapical indentation on vestigial termen; cilia plumbeous basally, dark brown distally. Hindwing ground color brown, distally darker, with whitish fascia subapically; in male, basal area covered with black lustered scales, and a whitish gray fascia along CuA2; cilia as in forewing.

Wing venation (n = 4). Almost as in G. triocellaris, but hindwing lacking A3, and M3 and CuA1 occasionally stalked basally.

Abdomen. Dorsally dark brown. Ventrally brown, with posterior margin of each segment white. tympanal organs as in G. triocellaris, but ramus tympani present as horizontal bar connected to venula prima laterally. Male 8th tergite with Y-shaped sclerotization medially. Male 8th sternite with long square sclerotization medially, posterior margin slightly concave.

Male genitalia (n = 9). uncus long, curved ventrally, apex pointed. gnathos subtriangular, at right angle from tegumen, dorsal side denticulate apically. long tegument, dorso- and ventrolateral margins forming sclerotized ridges; socii finger-shaped with two petaloid lobes apically. Slender valve; cucullus with a strongly sclerotized thorn apically; costal margin with dense long setae, with a short finger-like costal arm at base; sacculus short, triangular. Juxta heart-shaped, lateral sides extended as a pair of ventral arms. Saccule rounded. Phallus tapering posteriorly; apical thorn sheath-shaped, apex truncated; cornuti absent; ejaculatory duct connected at anterior end of phallus.

Female genitalia (n = 7). Papillae anales, anterior and posterior apophyses as in those of G. triocellaris. Lamella postvaginalis a long square plate, posterior margin slightly concave medially. Lamella antevaginalis a shorter square plate than lamella postvaginalis, anterior margin folded postero-internally, then strongly constricted and connected to ductus bursae. Ductus bursae membranous, short and thin. The seminal duct is located at anterior 2/3 of the ductus bursae. Corpus bursae ovate, approximately 2–3 times longer than ductus bursae, posterior half lightly sclerotized with smooth surface, anterior half membranous, with weak granules; signa absent.

Original research

Yuki Matsui, Junpei Hamaguchi, Sadahisa Yagi & Toshiya Hirowatari (2024). Two remarkable new species of Glaucocharis (Lepidoptera, Crambidae, Crambinae) from the Ogasawara Islands, Japan. Zootaxa 5543 (1): 083–096, DOI:10.11646/zootaxa.5543.1.4

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