Depressaria falkovitshi Lvovsky, 1990

Arashima, Hazumu, Yagi, Sadahisa, Sasaki, Kimitaka, Suzuki, Shinya & Hirowatari, Toshiya, 2025, Two species of Depressariidae (Lepidoptera: Gelechioidea) newly recorded from the grassland of southwestern Japan, Zootaxa 5647 (6), pp. 584-594 : 589-593

publication ID	https://doi.org/10.11646/zootaxa.5647.6.6
publication LSID	lsid:zoobank.org:pub:1D410D99-067D-4C04-B07C-AE78C60CEAEF
persistent identifier	https://treatment.plazi.org/id/B12C7D3E-FFFD-D076-1BA2-E778FF52FCC6
treatment provided by	Plazi
scientific name	Depressaria falkovitshi Lvovsky, 1990
status

Treatment

(Japanese name: Hiyoko-hirata-maruha-kibaga).

( Figs. 5–9 View FIGURE View FIGURE View FIGURE View FIGURE View FIGURE )

Depressaria falkovitshi Lvovsky, 1990: 73 .

Material examined.

[ Pale yellowish type.] JAPAN, Kyushu: 2♂ 1♀, Fukuoka, Kitakyushu-shi, Kokuraminami-ku, Hiraodai, 27.VIII.2016, K. Sasaki leg. , gen. slide. no. HA22-74, HA22-84, HA22-85; 3♀, same locality, 29.VIII.2020, S. Tomura leg. ; 2♀, same locality, 30.VIII.2020, J. Oku leg. , gen. slide. no. Oku 2020 No. 70 female; 1♂, same locality, 28.VIII.2021, K. Sasaki leg. ; 1♀, same locality, 30.VIII.2021, H. Arashima leg. ; 1♂ 1♀, same locality, 7.VIII.2022 (larva), host: Bupleurum stenophyllum , 12.VIII.2022 emerged, S. Suzuki leg. , gen. slide. no. HA24- 234; 3♂ 7♀, same locality, 13.VIII.2022 (larva), host: Bupleurum stenophyllum , 22–29.VIII.2022 emerged, S. Yagi leg. , gen. slide. no. HA24-246, HA24-247; 1♀, same locality, 21.VII.2023 (larva), host: Bupleurum stenophyllum , 3.VIII.2023 emerged, S. Yagi leg. ; 13♀, same locality, 10.VIII.2023, H. Arashima, I. Kawashima, J. Hamaguchi, Y. Matsui, K. Sasaki leg. , gen. slide. no. HA23-168, HA24-235, HA24-244, HA24-245; 1♀, same locality, 10.VIII.2023 (pupa), host: Bupleurum stenophyllum , 13.VIII.2023 emerged, H. Arashima, I. Kawashima, J. Hamaguchi, Y. Matsui leg. ; 7♂ 11♀, same locality, 10.VIII.2023 (larva), host: Bupleurum stenophyllum , 19–25.VIII.2023 emerged, H. Arashima, I. Kawashima, J. Hamaguchi, Y. Matsui leg. ; 1♀, same locality, 10. VIII. 2023 (pupa), 17.VIII.2023 emerged, I. Kawashima leg.

[ Ocher type.] JAPAN, Honshu: 1♂, Yamaguchi, Mine-shi, Akiyoshidai , 28.IX.2019, A. Miyano leg. , Kyushu: 1♀, Fukuoka, Kitakyushu-shi, Kokuraminami-ku, Hiraodai , 15.X.2016, K. Sasaki leg. ; gen. slide. no. HA22-81; 1♂, same locality, 20.IX.2020, K. Sasaki leg. , gen. slide. no. HA24-194; 1♀, same locality, 12.IV.2022, K. Sasaki leg. , gen. slide. no. HA24-195; 1♀, same locality, host: Bupleurum stenophyllum , 27.X.2022 emerged, K. Sasaki leg.

Diagnosis. This species is easily distinguished from other Depressaria species by its pale yellowish or ocher forewing color. However, the male genitalia of this species are similar to those of Depressaria depressana Fabricius, 1775 by sharing the shape of valva. This species can be distinguished from D. depressana by the following characteristics: the saccus is elongated but not so long (in D. depressana it is long and thin), and the phallus has a terminal process of the sclerotized tube on the ventral side with one or two lateral spines (in D. depressana , the phallus does not have a terminal process, though it has several aciculate cornuti). The female genitalia of this species can be distinguished from those of D. depressana by the ductus bursae swelling before antrum (in D. depressana , there is no swelling).

Redescription. [Pale yellowish type.] Male ( Fig. 5A View FIGURE ). Forewing length 5.8–7.2 mm (n = 14), wingspan 11.8– 15.5 mm (n = 14). Head, Antennae, labial palpus, thorax, and legs pale yellow. Forewing upper side pale yellow, with light brown dot at end of cell. Forewing underside beige, basal area rather cream color. Hindwing upper side yellowish white, costal margins and veins pale yellow, fringe white to pale yellow. Hindwing underside pale yellow. Abdomen pale yellow. Female ( Fig. 5B View FIGURE ). Forewing length 4.8–8.0 mm (n = 42), wingspan 11.0– 17.5 mm, (n = 42). Similar to males, but forewing and hindwing color tend to be pale.

[Ocher type.] Male ( Fig. 5C View FIGURE ). Forewing length 6.7–8.2 mm (n = 2), wingspan 14.4–16.3 mm (n = 2). Head beige. Antennae brown. Labial palpus beige with a dark brown ring near tip. Thorax beige with diffuse darker dot in middle. Legs ochre. Forewing upper side ochre, darker at basal area, dark brown dot at end of cell, terminal spots rather dark. Forewing underside dark gray. Hindwing upper side brownish gray, darker towards apex, costal margins and veins brown, fringe ochre. Hindwing underside gray. Abdomen ochre. Female ( Fig. 5D View FIGURE ). Forewing length 8.0– 8.8 mm (n = 3), wingspan 16.8–18.7 mm (n = 3). Similar to males.

Male genitalia ( Fig. 6 View FIGURE ). Uncus not developed. Socius broadly elliptic. Gnathos rounded, globular. Transtilla gradually expanding towards middle. Costal margin of valva widening sub-basally, ventral margin of valva broad at base, widening subapically, near its tip concave. Cuiller very short, incurved, not reaching costa, thick basally. Juxta flat. Saccus tapered toward tip. Phallus ( Fig. 6B View FIGURE ) elongated and gently curved upwardly; terminal process of sclerotized tube on ventral side with one or two lateral spines ( Fig. 6C–E View FIGURE ).

Female genitalia ( Fig. 7 View FIGURE ). Papilla analis rounded and tapering toward tip. Apophysis anterioris 2/7 length of apophysis posterioris. Ostium situated in middle of eighth sternite. Anterior margin of eighth sternite not bulged. Ductus bursae long with small, slightly sclerotized swelling beyond antrum; antrum with deep V-shaped incision, strongly sclerotized. Ductus seminalis arising before swelling of ductus bursae. Corpus bursae elliptic with a small signum with various-sized numerous spines, horizontally elongated.

Distribution. Japan (Honshu, Kyushu), new record; China ( Liu et al. 2014), Russia, Mongolia, and Kazakhstan ( Lvovsky 2016).

Host plant. Bupleurum stenophyllum ( Fig. 8A View FIGURE , Wan et al. 2015; Bai et al. 2017, see Remarks), B. chinensis ( Liu et al. 2014) ( Apiaceae ).

Biology. Young larvae feed on new leaves of the host plants; as they grow, they roll the leaves ( Fig. 8B, C View FIGURE ). The mature larvae make a web nest by spinning inflorescences ( Fig. 8D, E View FIGURE ). The larvae pupate in their nest ( Fig. 8F View FIGURE ) or a flattened cocoon made by radiating threads on the substrate ( Fig. 8G View FIGURE ).

In Japan, adults emerge twice a year during the host flowering season of host plants (in August–October ( Kitagawa 1982). The first-generation larvae feed on host plants from mid-July to late August, emerge as pale yellowish adults from August to early September, and lay eggs. Second-generation larvae feed on host plants from September to early October, emerge as ocher adults from late September to October, and then hibernate as adults. ( Fig. 9 View FIGURE ).

Remarks. This species is an important pest in China; the host plants, Bupleurum spp. , are used in herbal medicine ( Liu et al. 2014; Wan et al. 2015). In addition, Bai et al. (2017) reported B. falcatum as a host plants. However, we conclude that the plant is B. stenophyllum because this Bupleurum was introduced from Japan in this literature, and the species previously considered to be B. falcatum in Japan is now regarded as B. stenophyllum ( Ohta, 1998; Wang et al. 2011). In fact, B. falcatum is currently thought to be a species restricted to Europe ( Wang et al. 2011).

In this study, seasonal dimorphism was discovered in this species, representing the first documented case in the family Depressariidae . Although examples of seasonal dimorphism or polymorphism have been reported in several groups of microlepidoptera, such phenomena seem to be relatively uncommon. For example, in Japan, they have been reported in Lyonetiidae ( Lyonetia spp. ; Ahn & Hirowatari 2013), Scythrididae ( Scythris sinensis (Felder & Rogenhofer, 1875) ; Sakamaki 2013b), Gracillariidae ( Phyllonorycter spp. , Caloptilia spp. ; Kumata et al. 2013), Tortricidae ( Acleris spp. ; Nasu 2013), and Crambidae ( Paliga minnehaha (Pryer, 1877) ; Komatsu & Tomisawa 2024).