Caloptilia rhynchosiae, Yagi & Goto & Sohn, 2024

Yagi, Sadahisa, Goto, Kiyoshiro & Sohn, Jae-Cheon, 2024, A new species of Caloptilia (Lepidoptera: Gracillariidae) from Japan and Korea, Zootaxa 5446 (3), pp. 420-432 : 422-425

Caloptilia rhynchosiae n. sp.

( Figs 1–18 )

Diagnosis. This species is similar to Caloptilia leucothoes Kumata, 1982 in the external appearance and also to C. sapporella ( Matsumura, 1931) in having the cucullus through a neck in the male genitalia. It differs from the latter two in the presence of a saccular process on the valva of the male genitalia. In the female genitalia, C. rhynchosiae n. sp. is similar to C. soyella in having the entirely-membranous ductus bursae. It, however, differs from the latter in the presence of the roundly-bulged basal area of ductus seminalis (narrow and then bulged in C. soyella ) and a mortar-shaped sterigma (M-shaped in C. soyella ).

Description. Habitus ( Figs 1–3 )—No sexual dimorphism exhibited.

Head: Vertex brownish gray, with purple luster, tinged with white anteriorly; frons creamy white. Antenna ca. 1.1x longer than forewing; scape brownish gray; flagellum brownish gray with pale brownish gray annulations. Labial palpus upcurved; 1 st segment 1/4 as long as 2 nd segment, white; 2 nd segment as long as 3 rd segment, white to cream, intermixed with dark brown scales ventrally; 3 rd segment acuminating apically, white to cream, tinged with dark brown on distal 1/3.

Thorax: Patagium brownish gray; tegula and mesonotum pale-purplish gray, intermixed with pale grayish orange scales. Forewing length 3.8–4.3 mm, narrow, yellow, intermixed with lustrous, purplish brown scales on dorsal and distal areas; costa with 6–14 black strigulae, tinged with dark brownish gray basally; three apical strigulae black in some individuals; often one or two spots present at basal 1/4 and 1/2 of forewing; cilia dark brownish gray, peppered with pale gray on apical area and termen. Hindwing dark brownish gray, paler to base; cilia dark brownish gray. Fore- and midlegs with coxa, femur and tibia dark brown, sparsely irrorated with pale brownish gray; tarsomere white, with black ring distally. Hindleg with coxa cream, sparsely peppered with dark brown; femur pale gray with dark brown band at basal 3/5 laterally; tibia pale gray dorsally, white ventrally, intermixed with dark brown scales distally; tarsomeres pale brownish gray.

Abdomen: terga lustrous, gray; sterna white or pale gray.

Male genitalia ( Figs 4–7 )—Tegumen linguiform, narrowed basally; subscaphium of even width. Valva narrow, of even width in basal half; cucullus subtriangular, long-hairy except distal area with short setae; sacculus broad, 2/5 as long as valva, with large horn-like process at distal end. Vinculum linguiform, narrowly-round apically. Phallus narrow, slightly narrowed distally, with 14–20 cornuti.

Female genitalia ( Figs 8–10 )—Papilla analis pad-shaped. Apophysis posterioris broad basally, as long as apophysis anterioris; apophysis anterioris relatively broad, tapering distally. Ostium bursae present between sternite VII and VIII. Sterigma well-sclerotized, mortar-shaped with minute granules. Ductus bursae entirely membranous, with minute granules between ostium bursae and opening of ductus seminalis. Ductus seminalis arising from the posterior 4/5 of ductus bursae, roundly-bulged basally. Corpus bursae ovate, wrinkled; a pair of signa curved, sickle-shaped, with dentate inner margins.

Types. Holotype —male, Korea: Jeonnam Prov., Sinan-gun, Is. Jaeundo, Jaeun-myeon, Gojang-ri , Oegi sand-dunes (34°53′44.5″N 126°00′27.4″E), 16 July 2017 (JC Sohn), GJUE.

Paratypes (8♂ 7♀)—[ Japan] 1♂, Kyushu, Fukuoka Pref., Fukuoka-shi, Nishi-ku , Kuwabara , Ito Campus of Kyushu University (33°35’52.8”N 130°13’00.5”E), 2 June 2020, larva on Rhynchosia tomentosa , emerged on 10 June 2020 (S Yagi), [GSN] SY1326, [COI] SaY777, ELKU ; 3♂ 3♀, ditto, 3 July 2023, larvae on Rhynchosia tomentosa , emerged on 6–29 August 2023 (S Yagi), [GSN] SY1506 (♀), SY1508 (♂), ELKU ; 1♀, Kyushu, Kumamoto Pref., Uki-shi, Matsubase-machi , Toyofuku , 28 June 2023, larva on Rhynchosia tomentosa , emerged on 1 August 2023 (K Goto), ELKU ; 1♂ 1♀, ditto, 13 July 2023, larvae on Rhynchosia tomentosa , emerged on 24 & 26 July 2023 (K Goto), ELKU ; 2♀, ditto, 16 August 2023, larvae on Rhynchosia tomentosa , emerged on 28 August & 1 September 2023 (K Goto), ELKU . [ Korea] 2♂, same data as holotype, [GSN] SJC-1253, [COI] JCS-COI D-325, GJUE & NIBR ; 1♂, Gyeongnam Prov., Is. Geoje-do, Jangmok-myeon, Jangmunpo-waeseong (castle), 18 June 2004, [GSN] SJC-792, GJUE .

Distribution. Japan (Kyushu) and South Korea.

Etymology. The species epithet is derived from the generic name of the host plant.

Host plants. Fabaceae — Rhynchosia tomentosa var. tomentosa (L.) Hook, & Arn.

Biology. This species has been collected from the sand-dunes and coastal forests in Korea and the low mountain areas in Japan. These habitats are matching with where its host plants occur. The young larvae made a linear-blotch mine on the underside of a leaf or a trumpet-shaped mine on the upper side of a leaf ( Figs 11–12 ). The later instars of larvae made a cigarette-like leaf roll. The spindle-shaped cocoons ( Fig. 17 ) were formed inside/outside of the rolls. The larvae were collected mainly from the places that get a lot of sunshine from June to August and they were emerged in June to September, suggesting two or more generations per year.

Figures

FIGURES 1–3. Habitus of Caloptilia rhynchosiae n. sp. 1. Holotype, male (Korea: Jeonnam); 2. Paratype, female (Japan: Kumamoto); 3. Paratype, male (Japan: Fukuoka). Scale bars = 2.5 mm.

FIGURES 4–7. Male genitalia of Caloptilia rhynchosiae n. sp. 4. Whole genitalia with saccular process spread out and phallus removed (paratype: SY1326); 5. Valvae (paratype: SY1508); 6. Phallus (paratype: SY1508); 7. Genital capsule (paratype: SY1508). Scale bar = 0.5 mm.

FIGURES 8–10. Female genitalia of Caloptilia rhynchosiae n. sp. (paratype: SY1506). 8. Whole genitalia; 9. Ostium bursae; 10. Dentate signa. Scale bars = 0.5 mm (10), 0.1 mm (11, 12).

FIGURES 11–18. Biology of Caloptilia rhynchosiae n. sp. 11. Mine on the upper side of host leaf; 12. Mine on the underside of host leaf; 13. Young larva in the mine; 14, 15. Leaf rolls; 16. Mature larva; 17. Cocoon; 17. Resting adult.