Thiotricha elaeocarpiella Kyaw, Yagi & Hirowatari

Kyaw, Khine Mon Mon, Yagi, Sadahisa, Oku, Jouhei, Sakamaki, Yositaka & Hirowatari, Toshiya, 2019, Taxonomic study of Thiotricha Meyrick (Lepidoptera, Gelechiidae) in Japan, with the description of two new species, ZooKeys 897, pp. 67-99 : 67

Thiotricha elaeocarpiella Kyaw, Yagi & Hirowatari sp. nov. Figs 5A, B , 6A, B , 7E , 8I, J , 9E , 10E , 12 A–I , 13E, F , 14E, F

Cnaphostola sp. 2: Oku et al. 2018: 30, fig. 45.

Type material.

Holotype: Japan - Kyushu • 1 ♂, Fukuoka Pref., Kyushu Univ. Ito Campus, Nishi-ku; 7 Aug. 2017; S. Yagi, T. Hirowatari, K. M. M. Kyaw & C. Tsuji leg.; case on Rhaphiolepis indica (case made from flower bud of Elaeocarpus zollingeri ); 19 Aug. 2017 em.; gen. slide no. KM-88; in ELKU.

Paratypes: Japan - Kyushu [Fukuoka] • 1♂; same locality and collectors as holotype; 26 May. 2017; portable case on Rhaphiolepis indica ; 17 Jul. 2017 em.; gen. slide no. KM-40 • 3♂♂; same locality and collectors as holotype; 31 Jul. 2017; Host: Rhaphiolepis indica ; 7 Aug. 2017 em.; gen. slide no. KM-104,105 • 2♂♂; same locality and collector as holotype; 22 Jul. 2017; Host: Rhaphiolepis indica ; 31 Aug. 2017 em. • 1♀; same locality; 22 Jul. 2017; Host: Rhaphiolepis indica ; 27 Aug. 2017; K.M.M.Kyaw leg.; gen. slide no. KM-132. - Kyushu [Kagoshima] • 1♀; Satahetsuka (L), Minamiousumi Town; 9-10 Jul. 2011; T. Terada leg. (KGU). - Ryukyus [Kagoshima] • 1♂, 1♀; Amami-Oshima Is., Mt. Yuwan-dake, Uken; 17 Aug. 2012; S. Sameshima leg.; gen. slide no. KM-23(♂), 56(♀); KGU • 1♀; same locality; 4 May. 2013; K. Tsuda leg.; KGU • 1♀; same locality; 4 Aug. 2014; S. Sameshima leg.; KGU • 1♂; same locality; 5 May. 2015; S. Sameshima leg. (KGU); gen slide no. KM-24 • 4♀♀; Akatsuchiyama, Yuwan, Uken-son, 245m; 6 Jul. 2016; LT; S. Yagi leg.; KM-82; 116; 125. - Ryukyus [Okinawa] • 1♂; Okinawa ken, Higashi son Kunigami, Takae; T. Hirowatari, S. Yagi, K.M.M.Kyaw leg. • 1♀; Kenmin no-mori, Afuso; 11 Aug. 2017 (larva); Host: Elaeocarpus zollingeri ; 29 Aug. 2017 em.; same collectors; gen. slide no. KM-89.

Diagnosis.

At a glance, the external features are similar to those of T. chujaensis (Park, 2016) comb. nov. but it can be distinguished by wing markings in the distal yellow zone of the forewing, which lacks a distinct blackish streak below the middle of the yellow zone and features grayish scales at the costal margin before the apex and the area beyond the tornus. Additionally, it can easily be distinguished based on the male genitalia; the uncus is more rounded apically; the gnathos is U-shaped and acute apically; the valva is narrowly elongate with a sharped pre-apical process ca. 1/4 of the way along its length and the vinculum lacks thumb-like lobes posteriorly; the saccus has a rounded base. The shape of the phallus is also different. However, the male genitalia are similar to those of Thiotricha clidias Meyrick, 1918, which was described from Khasi Hills, India, although they differ in the shape of the phallus. In T. clidias Meyrick, 1918, the phallus is rounded basally, abruptly sinuate and slender in distally but as a cucurbit-shaped in T. elaeocarpiella sp. nov.

Description.

Male ( Figs 5A , 6A , 7E ) Forewing length 2.9 mm in holotype, 2.6-3.4 mm in paratypes. Wing expanse 6.4 mm in holotype, 5.2-7.1 mm in paratypes.

Head: shiny creamy white with appressed scales. Antennae filiform, basal segment elongate and creamy white, sparsely speckled with brown scales; flagellum grayish white on dorsal surface before midpoint, then brownish gray beyond on its dorsal and ventral surfaces, with extraordinarily long and fine cilia ventrally. Labial palpus white, moderately long and recurved; first segment approximately half the length of the second, with blackish gray scales on lateral surface; second segment as much as 1.5 times the length of the first, creamy white throughout on outer surface; bundle of hair pencils arising from apex of first and second segment, appressed on dorsal surface to near the end of the third segment; third segment as thick as second, with blackish gray scales medially on lower surface ventrally, shiny creamy white evenly on both surfaces, apex sharply acute ( Fig. 6A ).

Thorax: creamy white. Tegula shiny, creamy white dorsally, ornamented with blackish gray scales along anterior margin.

Legs: white; forefemur, tibia, and tarsus suffused inwardly with blackish brown; scattered with white scales on outer surface; mid femur entirely white; mid tibia and tarsus white but slightly speckled with blackish brown scales on outer surface; hind femur white; hind tibia creamy white, with a row of long, stiff, stout, creamy white bristles above and below, suffused with a small blackish gray scale on lateral outer surface posteriorly; first tarsal segment entirely blackish gray; second and third segment white with blackish gray apical ring; last two segments white.

Forewing: eleven veins, R4 + M1 stalked, R5 absent, anal vein furcate ( Fig. 7E ). Forewing ground color shiny grayish white to white to ca. 3/4 of the way from base; distinct orange zone in distal 1/4, deeply concave along costal margin; costal margin and area beyond tornus grayish colored; small black spot at apex, narrowly connected to another black spot in tornus; cilia before apex to tornus brown, creamy yellow from tornus to inner base of wing.

Hindwing: narrower than forewing, creamy white to grayish white, with pale orange apical zone; apex sharply produced, with small apical black spot; cilia well-fringed to base, fringe around apex creamy white, with broad, dark brown median band.

Male genitalia: ( Figs 8I, J , 9E ) eighth abdominal sternite more or less triangular, emarginate at the tip, slightly broadened basally with moderately sclerotized margin anteriorly, gradually narrow toward apex. Uncus directed backwards, with broad basal expansion, then narrowly elongate, forming a furrow on lower surface medially, bearing short spines on its lateral margin and abruptly rounded with short and fine setae evenly on its apical dorsal surface. Gnathos U-shaped, stout, strongly bent at basal 1/3, sharply acute apically. Tegumen longer than uncus, slightly concave medially on lateral margins with dense hairs on dorsal surface beyond middle. Anellus lobe, a large process, as much as 1/2 the length of process of valva, ovate membranous pouch at base, with short sclerotized apical spine and short fine setae around apical spine. Valva slender, elongate, broad basally, narrow along 2/3 of length, then dilated apically with dense, long, fine hairs hanging down from its inner surface and developing a sclerotized point, spine-like pre-apical process arising from its base, nearly 1/4 of apex. Vinculum long and slightly narrow, with few rather long setae on its lateral margin. Saccus roundly produced basally. Phallus cucurbit-shaped in basal half, slightly sinuate, slender and recurved upwardly in distal half.

Female ( Figs 5B , 6B ). Forewing length 2.5-3.3 mm. Wing expanse 5.3-7.1 mm. Similar to male but differs as follows: Labial palps of first segment shortest, with creamy white scales, as thick as second segment; second segment as long as third segment and with white scales on lower surface and grayish or grayish brown scales on upper surface; third segment slender and acute with gray to grayish-brown scales on both surfaces ( Fig. 2B )

Female genitalia: ( Fig. 10E ) papillae anales with long and short fine setae on its entire surface. Apophysis posterioris longer than apophysis anterioris; apophysis anterioris ca. 1/3 the length of posterioris. Ductus bursae rather long, narrow, slightly sclerotized along the posterior half of its length. Corpus bursae clavate in shape; signum rounded at center.

Distribution.

Japan (Kyushu, Ryukyus).

Etymology.

The name refers to its main host plant, Elaeocarpus zollingeri .

Host plant.

Elaeocarpus zollingeri ( Elaeocarpaceae ), Rhaphiolepis indica ( Rosaceae ).

Biology

( Fig. 12 ). The larva uses the flower bud or the young shoot of its host plant to construct portable cases. When it utilizes a flower bud, at first, the larva penetrates the bud and then lives and feeds within it. After that, it moves from one flower to another by carrying the bud and attaching it to other flower buds to complete its life cycle ( Fig. 12D, E ). When the larva is ready to pupate, it attaches the case to the underside of a leaf with silk. When it utilizes a young shoot ( Fig. 12C ), the larva leaves small dot-like traces of feeding after making cases by the shoot. Pupation also takes place inside the portable cases. After completing development, the adult emerges from the case, leaving the pupal exuvia inside.

Pupa

( Figs 13 D–F , 14 A–D ). Length ca. 3.2 mm, cylindrical. Color yellowish brown. Vertex armed with many minute spines. Prothorax with a pair of triangular projections on anterolateral corners of tergite. Antenna and forewing reaching to posterior margin of 6th abdominal segment. Forelegs extending to 3rd abdominal segment; midlegs reaching to mid-way of 5th abdominal segment; hindlegs also extending to just beyond the anterior margin of 7th abdominal segment. Seventh abdominal segment armed with a row of distinct tergal spines directed posteriorly on anterior margin and indistinct short tergal spines on caudal margin. Seventh abdominal sternite with a pair of oval pads also armed with a row of spines directed anteriorly. Tenth abdominal segment with a pair of triangular projections at middle, no true cremaster present.

Remarks.

Although this new species was found on two different plants in the present study, it may be that E. zollingeri is mainly utilized as the host plant and occasional feeding on R. indica occurs when individuals happen to come into contact with this plant. See discussion.

Figures

Figure 2. Male genitalia. Thiotricha biformis. Scale bar: 0.4 mm.

Figure 5. Adults of Thiotricha spp. A T. elaeocarpiella sp. nov., male (holotype) B ditto, female (paratype) C T. flavitermina sp. nov., male (holotype) D ditto, female (paratype) E ditto, male (paratype) F ditto, female (paratype). Scale bars: 2 mm.

Figure 6. Labial palps of Thiotricha elaeocarpiella sp. nov. A male with hair pencils, paratype B female without hair pencils., paratype. Scale bars: 0.4 mm.

Figure 7. Wing venation of Thiotricha spp., male. A T. biformis B T. angustella comb. nov. C T. venustalis comb. nov. D T. chujaensis (Park, 2016) comb. nov. E T. elaeocarpiella sp. nov., paratype F T. flavitermina sp. nov., paratype.

Figure 8. Male genitalia of Thiotricha spp. A, B T. biformis A male genitalia, gen. slide no. KM- 143 B phallus C, D T. angustella comb. nov. C male genitalia, gen. slide no. KM- 106 D phallus E, F T. venustalis comb. nov. E male genitalia, gen. slide no. KM- 1 F phallus G, H T. chujaensis (Park, 2016) comb. nov. G male genitalia, gen. slide no. KM- 43 H phallus I, J T. elaeocarpiella sp. nov., holotype I male genitalia, gen. slide no. KM- 88 J phallus K, L T. flavitermina sp. nov., holotype K male genitalia, gen. slide no. KM- 100 L phallus. Scale bars: 0.4 mm (genitalia), 0.2 mm (phallus).

Figure 9. Abdominal segments of Thiotricha spp. A T. biformis. B T. angustella comb. nov. C T. venustalis comb. nov. D T. chujaensis (Park, 2016) comb. nov. E T. elaeocarpiella sp. nov., paratype F T. flavitermina sp. nov. Scale bars: 1 mm.

Figure 10. Female genitalia of Thiotricha spp. A T. biformis, gen. slide no. KM- 145 B T. angustella comb. nov., with close up of signum, gen. slide no. KM- 118 C T. venustalis comb. nov., gen. slide no. KM- 52 D T. chujaensis (Park, 2016) comb. nov. with close up of signum, gen. slide no. KM- 128 E T. elaeocarpiella sp. nov. with close up of signum, paratype, gen. slide no. KM- 132 F T. flavitermina sp. nov. with close up of signum, paratype, gen. slide no. KM- 55. Scale bars: 0.5 mm.

Figure 12. Biology of Thiotricha elaeocarpiella sp. nov. and its host plant A host plant, Elaeocarpus zollingeri (Elaeocarpaceae) B host plant, Rhaphiolepis indica (Rosaceae) C larval portable case made of a young shoot of R. indica on the underside of the leaf D larval portable cases made with flower buds of E. zollingeri E close up of larval portable cases F different types of portable cases. Left arrow indicates the portable case made of E. zollingeri, right arrow indicates the portable case made of R. indica G larva within the flower bud H pupa exuviae I resting posture of adult, dorsal view.

Figure 13. Pupa of Thiotricha spp. A-C T. chujaensis (Park, 2016) comb. nov. D-F T. elaeocarpiella sp. nov. A, D dorsal view B, E ventral view C, F lateral view. Scale bar: 0.1 mm.

Figure 14. Pupa of Thiotricha chujaensis (Park, 2016) comb. nov. A head, lateral view Arrow indicates many minute spines on vertex B seventh abdominal segment, ventral view Arrow indicates oval pad armed with a row of spines C seventh abdominal segment, dorsal view Arrow indicates a row of spines on both anterior and caudal margin D seventh abdominal segment, lateral view Arrow indicates oval pad armed with a row of spines and rows of tergal spines. Scale bar: 0.1 mm.