Palumbina muraseae Kyaw & Yagi, 2023

Kyaw, Khine Mon Mon, Yagi, Sadahisa, Oku, Johei & Hirowatari, Toshiya, 2023, Taxonomic study of Palumbina Rondani (Lepidoptera, Gelechiidae, Thiotrichinae) in Japan: biology, immature stages, and a new species, ZooKeys 1165, pp. 61-99 : 61

Palumbina muraseae Kyaw & Yagi sp. nov.

Figs 3C-F , 4 , 5 , 6F , 7F , 8F , 9D , 13 , 22 , 23 Japanese name: Murase-mongin-hoso-kibaga

Thyrsostoma sp.: Murase 2009: 140, figs 13-17.

Palumbina sp. 2: Oku et al. 2018: 32, fig. 47.

Type material.

Holotype: Japan - Ryukyus •♂; Kagoshima Pref., San Tokunoshima; 9. Jul. 2016; Sadahisa Yagi leg.; gen. slide no. KM-374; ELKU. Paratypes: Japan - Kyushu [Kagoshima] • 2♂♂; Yakusima Is., Hirauti; 19 Sep. 1978; Y. Arita leg.; gen. slide no. KM-342; NSMT. • 1♂, 1♀; Yakusima, Satunan Is.; 17 Oct. 1973; T. Kumata; gen. slide no. KM-343; SEHU. - Ryukyus [Kagoshima] • 3♂♂, 1♀; Amamioshima Is., Mt. Yuwan-dake; 15 Nov. 2012; S. Sameshima leg.; gen. slide no. KM-334(♂), 335(♂), 336(♂), 345(♀); KGU. • 1♀; same locality; 18 Nov. 2012; K. Tsuda & S. Sameshima leg.; gen. slide no. KM-349; KGU. • 1♂; same locality; 23 May 2014; gen. slide no. KM-341; KGU. • 1♀; same data except 5 May 2015; KGU. • 3♂♂, 2♀♀; Amamioshima Is., Uken-son, Ohata; 14 Sep. 2002; Host: Distylium racemosum ; T. Ueda leg.; 27 Sep-3 Oct. 2002 em.; OPU. • 1♂; Amamioshima Is., Mt. Akatuti, Uken-Son; 21 Sep. 2012; S. Sameshima leg.; gen. slide no. KM-337; KGU. • 2♂♂; Amamioshima Is., Mt. Akatuti; 19 Nov. 2012; K. Tsuda & S. Sameshima leg.; gen. slide no. KM-339; KGU. • 1♂; same data except 7 Mar. 2013; gen. slide no. KM-338; KGU. • 1♂; same data except 27 May 2015; gen. slide no. KM-340; KGU. • 2♂♂, 2♀♀; Amamioshima Is., Sumiyou-son, Yakukatsu; 12-15 Sep. 2002; Host: Distylium racemosum ; T. Ueda leg.; 27 Sep. - 3 Oct. 2002 em.; OPU. • 2♀♀; Amamioshima Is., Kamiya, Sumiyo-Son; 23 May 2015; S. Sameshima leg.; gen. slide no. KM-346; KGU. • 1♀; Tokunoshima Is., Yamakubiri-rindo, Tokunoshima-Town; 2 May 2015; Y. Sakamaki leg.; gen. slide no. KM-344; KGU. • 1♂; same data as holotype, ELKU. - [Okinawa] • 1♂; Okinawajima Is., Mt. Nishime, Benoki; 8 Aug. 2017, LT; S. Yagi, T. Hirowatari, K.M.M. Kyaw leg.; ELKU. • 1♂; Okinawajima Is., Kunigami-gun, Kunigami-son, Uka; 31 May 2015, LT; S. Yagi leg.; ELKU. • 1♀; Okinawajima Is., Benoki, Kunigami-son, Mt. Terukubi, 330m; 4 Aug. 2015; S. Yagi leg.; gen. slide no. KM-348; ELKU. • 1♂, 1♀; Okinawajima Is., Kunigami-son, Yona; 23 Mar. 2002; Host: Distylium racemosum ; 13-15 Apr. 2002 em.; gen. slide no. KM-427(♀); OPU. •1♀; same data except; 24 Mar. 2002; OPU. • 1♀; same locality; 24 Mar. 2002; T. Saito leg.; OPU. • 1♂1♀; Okinawa-Is., Iji, Kunigami-Gun; 2 Jun. 2017 (320m); Y. Kitajima leg.; KGU. • 3♀♀; same locality, 25 Mar. 2021, LT (317m); S. Tomura leg.; ELKU. • 1♀; Okinawajima Is., Ookuni-rindo (Kunigami-son); 2 May 2000; T. Saito leg.; OPU. • 8♂♂, 3♀♀; Okinawa Is., Yaka, Kin-cho, Kunigami-gun, 25 Mar. 2021 (larva); Host: Distylium racemosum ; 15-21 Apr. 2021 em.; S. Yagi leg.; ELKU. • 1♀; Ishigakijima Is., Mt Yarabu, Sakieda; 5 Jul. 2017; S. Yagi leg.; ELKU. • 1♂1♀; Ishigakijima Is., Ishigaki-shi, Mt. Omoto; 18 Mar. 2002; I. Ohshima leg.; ELKU. •1♂; Ishigakijima Is., Ishigaki-shi, Funra, 15 Mar. 2002; I. Ohshima leg.; ELKU. • 1♀; Ishigakijima Is., Hirae, Oyamizu-hiroba; 4 Jul. 2017; S. Yagi leg.; gen. slide no. KM-347; ELKU.

Diagnosis.

This species can be easily distinguished from other congeneric species by having a yellowish ocher or dark brown color with small white patches at the base and before the apex in the forewing, racket-shaped anellus lobes, uncus basally with a knob with numerous stout setae ventrally, extremely broad succus in the male genitalia, and rectangular process of signum in the female genitalia.

Description.

Male (Figs 3C, E , 4A-C , 5A-C, E , 6F , 7F ).

Head. glossy white to fuscous. Scape creamy-white to ocherous-white; flagellum fuscous; cilia as long as width (Fig. 4A ); flagellomeres I and II usually not entirely separated (Fig. 5A, B ). Labial palpus creamy white, recurved, sexually dimorphic and modified in male; stout, shorter than female; segment I with outer surface fuscous, shortest, and as thick as segment II; segment II with expansible hair pencils arising from furrow on the ventral surface, reaching sub apex of segment III (Fig. 4C ); segment III as long as segment II, dorso-distal half fuscous. Proboscis scaly white.

Thorax. Dorsum of thorax and tegula white to yellowish ocher. Legs creamy white; fore femur creamy-white, fore tibia with fuscous on the outer surface and sometimes on the inner surface, fore tarsus black on the outer surface, each tarsomere ringed black apically on inner surface; mid-femur white on the outer surface and creamy yellowish on inner surface; mid-tibia creamy white with three black spots, mid tarsus creamy white; first tarsomere black at middle and apex, remaining tarsomeres ringed black apically; hind femur creamy white, hind tibia suffused with black at 1/3 and apex near tibial spur at ca. middle on outer surface; bearing long bristles along basal 2/3 of dorsal margin and with whorls of bristles at the apex (Fig. 4E ); hind tarsus, mostly fuscous.

Forewing. Length 3.8 mm in holotype, 2.9-3.9 mm in paratypes (n = 9). Wing expanse 8.4 mm in the holotype, 6.1-8.5 mm in the paratypes (n = 9) (Fig. 3C, E ). 11 veins: Sc reaching basal 1/2 of costa, R1 and R2 free, R3 and R4 short-stalked, R5 absent, M1 connate with R3+4, M2 remote from M3, CuA1 parallel to CuA2, CuA2 indistinct, 1A+2A forked at the base (Fig. 5E ); ground color yellowish ocher to brown, mostly with yellowish ocher reflections in holotype, sometimes suffused with creamy white at ~ 1/4 near the base and ~ 1/4 before the apex, sometimes delineated with black scales throughout the costal margin from its base to ~ 1/2 forewing length before apex; expansible pale yellowish ocher hair pencils beneath costa on ventral surface (Fig. 4B ); cilia well-fringed, yellowish ocher from its apex to tornus, yellowish white to the inner base of forewing.

Hindwing. Narrower than forewing, 8 veins, R1 join with Sc near the base, Rs and M1 stalked at distal 1/5, M2 remote from M3, CuA1 and CuA2 parallel (Fig. 5E ), creamy white with yellowish brown margin from costal area to beyond tornus; with a row of bristles arising from basal 1/6 to 1/5 of costa; cilia well-fringed, yellowish brown throughout to tornus, yellowish white to the inner base of hind wing.

Abdomen (Fig. 7F ). Coremata absent. Terga and sterna 1-7 unmodified. Sternum 8 large, rounded with sclerotized margin, slightly daunted at the middle on posterior margin.

Male genitalia (Fig. 6F ). Uncus fan-shaped, bearing a few setae on its dorsal surface, with a narrow furrow from its base to ~ 1/2 distance of its ventral surface, forming a long and small knob basoventrally, bearing numerous microtrichia ventrally with many stout setae apically. Culcitula present. Tegumen ~ 2.5 × longer than uncus, broadly concave on the anterior margin. Gnathos hook long and recurved upwards, moderately stout at ~ 2/3 basally, taper towards apically with slightly pointed tip. Valva ~ 1.3 × as long as tegumen, broadened basally, gradually narrowed to ~ 1/2 length, then elbowed at ca. its middle and slightly curved towards apex, uniformly elongated with rounded tip, densely setose with numerous short and long fine setae on the apical inner surface. Anellus lobe small and ~ 1/8 length of valva, racket-shaped with flexible long setae on the tip and numerous short setae on the ventral surface. Saccus extremely broad, sub-triangularly produced towards apex. Juxta with a pair of rather long and beak-shaped processes with pointed tip bearing fine setae apically. Phallus long, basal 1/4 dilated, 3/4 slender and sinuous, interior sclerite arising from its basal 1/4, nearly reaching the apex.

Female (Figs 3D, F , 4D , 5D ). Forewing. Length 3.1-4.2 mm (n = 9), wing expanse 7.0-9.1 mm (n = 9).

Head. Similar to males, but it differs as follows: flagellum without ciliation, labial palpus slender; segment II dorso-distally fuscous; segment III brown to fuscous.

Female genitalia (Fig. 8F ). Papillae anales bilobed. Apophyses long. Apophysis anterioris ~ 3/5 length of apophysis posterioris. Tergum 8 divided into two sclerites, with their inner margins close posteriorly and remote anteriorly. Sternum 8 narrowly elongated and projected into funnel-shaped sclerotized structures. Antrum broad and heavily sclerotized. Ductus bursae moderately broad and short, dilated near antrum. Corpus bursae oblong; signum situated in the middle, basal plate more or less oblong with a sclerotized ridge medially on its surface, with a rectangular process inwardly bearing a row of teeth apically.

Larva (Fig. 13I ). Length ~ 2.6-3.1 mm (n = 10), slender. Head semi-globular. Body pale yellow in early instars and yellowish brown with black pigmentation on ocellar area and on anterior margin of labrum in late instars. Prothoracic shield yellowish brown, blackish brown on caudal margin in later instars. Thoracic leg short, pale yellowish brown. Body creamy white. Pinaculum circular, blackish brown on T1-T3 and A1, A2, A8, and A9, and paler on remaining abdominal segments. Anal shield heavily sclerotized, yellowish brown. Anal fork present. Anal prolegs with many minute spines on the dorsal surface.

Pupa (Figs 22 , 23 ). Length 3.5-4.2 mm (n = 4), cylindrical. Color yellowish, dark brown emergence. Head semi-globular. Vertex with many minute granular spines. Prothorax with a pair of more or less wedge-shaped projections on dorsolateral corners of tergite (Fig. 23A ). Antennae extending to anterior margin of A6. Forewings extending to the middle of A6. Maxilla (galea) basally broad, gradually narrowing and extending to near posterior margin of A4. Prothoracic legs extending to near posterior margin of A2; mesothoracic legs extend to near posterior margin of A4; metathoracic legs extend to the posterior margin of A7. A5-A10 movable. A5 and A6 with a transverse row of dot-like spinules on the anterior margin (Fig. 22C ). A7 with transverse tergal spinules directed anteriorly on the anterior margin (Fig. 22A ). Sternite A7 with a pair of oval pads armed with a row of spinules directed anteriorly (Fig. 22B ). A10 delineated with a row of short spinules at the outer margin posteriorly (Fig. 22A ); apically with three pairs of hooked setae on ventral surfaces of A9 and A10; no true cremaster present.

Etymology.

The scientific name of the species is dedicated to Ms. Masumi Murase, who first collected the species and reported its biology.

Distribution.

Japan (Kyushu, Ryukyus).

Host plant.

Distylium racemosum Siebold et Zucc. ( Hamamelidaceae ).

Biology

(Fig. 13 ). The larvae mine at the midrib of the leaf to complete their growth and development (Fig. 13C ). The small holes seem to be used not only for entering the midrib but also for ejecting its feces. It leaves its mine after it gradually matures. After leaving, the larva cuts transversely at ~ 1/3 of the apical leaf and makes it into a shelter. The larva usually consumes leaves from its shelf around the radius it can reach. Eventually, the larva cut the leaf into a small and irregular shape to construct a portable case (Fig. 13E, F ). Later, the larva repeats this process until pupation, accumulating and stacking these small leaf pieces into a compact and more or less circular shape (Fig. 13G, H ). When the larva is close to pupating, it fixes its case and pupates in its case (Fig. 13K ). The adult emerges and leaves the pupal exuvia inside (Fig. 13L ). Murase (2009) pointed out that the resting posture of emerged adults is similar to that of stathmopodid species, keeping their hindlegs upwards, shown in Fig. 9D .

Remarks.

Murase (2009) reported this species as an undetermined species feeding on the host plant Distylium racemosum and described larval feeding: making a portable case on that host plant, wherein the larva cuts the young leaves into a circular shape and then feeding inside the case. Subsequently, the larva moved with its case and fixed it to the lower surface of the leaf or the wall of the rearing container. Finally, the larvae were transformed into pupae inside the case. This species has already been recorded as Palumbina sp. 2 ( Oku et al. 2018) on Amami Oshima Island in Japan.

Figures

Figure 3. Adults of Palumbina spp. A P. macrodelta, male B ditto, female C P. muraseae sp. nov., male, holotype E male, paratype D, F ditto, female, paratypes. Scale bars: 4.0 mm.

Figure 4. External morphological characters of P. muraseae sp. nov. A male antenna B the ventral surface of the wing. The arrow indicates expansible hair pencils beneath costa C labial palpus of male modified with long expansible hair pencil D labial palpus of female E hind leg F mid-leg. The arrows indicate two black spots. Scale bars: 1.0 mm.

Figure 5. Antenna, labial palpus, and wing venation of P. muraseae sp. nov. A, B basal part of the male antenna. The arrow indicates unseparated flagellomeres I and II C labial palpus of male D labial palpus of female E male fore and hind wing venation. Scale bars: 0.40 mm (A, C, D); 0.20 mm (B); 1.0 mm (E).

Figure 6. Male genitalia of Palumbina spp. A P. pylartis, genitalia slide no. KM- 383 B P. acerosa, genitalia slide no. KM- 320 C P. grandiunca, genitalia slide no. SY 1454 D P. operaria, genitalia slide no. KM- 389 E P. macrodelta, genitalia slide no. SY 1455 F P. muraseae sp. nov., holotype, genitalia slide no. KM- 374. Scale bars: 0.40 mm.

Figure 7. Abdominal segments of Palumbina spp. A P. pylartis, slide no. KM- 383 B P. acerosa, slide no. KM- 320 C P. grandiunca, slide no. SY 1454 D P. operaria, slide no. KM- 389 E P. macrodelta, slide no. SY 1455 F P. muraseae sp. nov., holotype, slide no. KM- 374. Scale bars: 1.0 mm.

Figure 8. Female genitalia of Palumbina spp. A P. pylartis, genitalia slide no. KM- 330 B P. acerosa, genitalia slide no. KM- 381 C P. grandiunca, genitalia slide no. SY 1453 D P. operaria, genitalia slide no. Palumbina No. 1 E P. macrodelta, genitalia slide no. KM- 328 F P. muraseae sp. nov., whole genitalia, genitalia slide no. KM- 348 and signum, genitalia slide no. KM- 427. Scale bars: 0.50 mm.

Figure 9. Resting position of adult Palumbina spp. A P. pylartis, female B P. acerosa, female C P. grandiunca, female D P. muraseae sp. nov., male.

Figure 13. Palumbina muraseae sp. nov. and its host plant. A habitat B host plant: Distylium racemosum (Hamamelidaceae) C infected young leaf, arrow indicates small holes made by the larva D midrib of leaf mined by the larva and the larva feeding inside it (red square) E upper leaf tip cut by the larva F larval leaf case on the upper leaf surface G larval leaf case on the lower leaf surface H close up of larval leaf case I young larva inside the fresh leaf case J mature larva inside the dried leaf case K pupa L pupal exuvia left by an adult.

Figure 22. Female pupa of P. muraseae sp. nov. A dorsal view B ventral view C lateral view. A arrow on A 7 indicates a transverse row of tergal spinules near anterior margin and arrow on A 10 indicates short spinules B arrow indicates an oval pad equipped with a row of spinules C arrow on the vertex of the head indicates many minute spines arrows on A 5 and A 6 indicate a transverse row of dot-like spinules. Scale bars: 1.0 mm.

Figure 23. Male pupa of P. muraseae sp. nov. A ventral view B lateral view C dorsal view.