Thiotricha gracilis, Lee & Li, 2024

Lee, Ga-Eun & Li, Houhun, 2024, A taxonomic review of Thiotricha Meyrick, 1886 (Lepidoptera, Gelechiidae, Thiotrichinae) from China, with descriptions of 84 new species, Zootaxa 5449 (1), pp. 1-222 : 23-24

publication ID	https://doi.org/ 10.11646/zootaxa.5449.1.1
publication LSID	lsid:zoobank.org:pub:CAC513A2-D2B4-4E6E-BAB6-CCE6E054680F
DOI	https://doi.org/10.5281/zenodo.11232945
persistent identifier	https://treatment.plazi.org/id/03CC3667-982D-1D68-FF05-8EBCDB69E30A
treatment provided by	Plazi
scientific name	Thiotricha gracilis
status	sp. nov.

Treatment

Thiotricha gracilis sp. nov.

( Figs 6F View FIGURE 6 , 23E View FIGURE 23 , 29E View FIGURE 29 , 47E View FIGURE 47 )

Type material. Holotype ♂, CHINA, Guizhou Province, Mayang River, Lijiaba (28.53°N, 108.48°E), 700 m, 30.ix.2007, leg. Hui Zhen, genitalia slide no. LGE18044 GoogleMaps . Paratypes. CHINA: Guizhou Province: 3 ♂♂, 13 ♀♀, same data as holotype except 30.ix−1.x.2007 GoogleMaps , genitalia slide nos. LGE16140f, LGE 17053m, LGE18071f; 4 ♀♀, Maojia Village, 800 m, Mayang River , 3−5.x.2007, leg. Hui Zhen ; 1 ♀, Suoluo (28.43°N, 106.02°E), 240 m, Chishui , 23.ix.2000, leg. Haili Yu GoogleMaps , genitalia slide no. LGE18073; 1 ♂, Linjiang (28.15°N, 105.9°E), Xishui County, 500 m, 25.ix. 2000, leg. Haili Yu. GoogleMaps

Diagnosis. Thiotricha gracilis can be recognized by the dull-colored narrow forewing with a fuscous median line. The male genitalia are very similar to those of T. vittata , but the uncus is more slender, the valva is more narrowed in basal 1/3 and the saccus is much longer in T. gracilis . The female genitalia are somewhat similar to those of T. atralata and T. vittata , but T. gracilis has slightly smaller papillae anales and longer signum. The most distinctive characteristic separating those species is the position of minute spines on the papillae anales, although this structure is very small and not easily recognizable. In T. gracilis , the spines broadly cover papillae anales except the anterior margin whereas they only cover the posterior 1/2 and the posterior margin in T. vittata and T. atralata , respectively. Thiotricha lativalva has papillae anales covered with spines similar to those of T. gracilis , but the anterior margin is more strongly sclerotized in the former.

Description. Adult ( Fig. 6F View FIGURE 6 ). Wingspan 11.5−12.5 mm. Head creamy white. Labial palpus creamy white, suffused with fuscous on outer and ventral surfaces; segment III slightly shorter than II, pointed at apex. Antenna with scape creamy white except posterior margin fuscous; flagellum brown to fuscous, basal 1/2 or 1/3 creamy white on dorsal surface, male cilia as long as diameter. Thorax cream to ochreous, fuscous posteriorly. Tegula cream to ochreous, anterior margin fuscous. Forewing narrow, dirty cream, sprinkled with dark grey and fuscous, anterior edge of costa black in basal 1/2, markings dark grey: a slender costal streak from distal 1/3, running obliquely toward termen; beyond and parallel to this another costal streak running from distal 1/4 to apical spot; apical spot elongated, dark fuscous, sometimes indistinct; anterior 1/4 of wing sometimes with a longitudinal streak running from base toward apex, broadened beyond middle, merged with a costal streak near apex; a fuscous longitudinal median line from distal 1/2, slender, interrupted at 1/3, meeting a costal streak near apex, below this usually broadly suffused with dark grey scales; basal 1/2 of dorsum with a broad band, its anterior margin sometimes suffused with fuscous scales distally; fringe of apical area creamy with black terminal band, remaining fringe light grey. Hindwing dark grey, fringe light grey. Legs cream mixed with dark grey; fore leg dark fuscous on outer surface, mid tibia cream at apex, mid tarsus cream at apex of each tarsomere, hind leg as in mid leg.

Male sternum VIII ( Fig. 23E View FIGURE 23 ). 1/5 length of abdomen, sharply narrowed from base to posterior 2/3, bifurcate approximately from posterior 1/3 with slender tines, each tine blunt at apex.

Male genitalia ( Fig. 29E View FIGURE 29 ). Uncus spatulate, sparsely setose apically. Gnathos hook moderately long. Tegumen approximately 3 times as long as uncus, anterior margin indented in pentagon-shape. Valvae asymmetrical, with right valva slightly broader medially; base narrow and slightly curved inward; costa broadly concave before middle, nearly straight distally; ventral margin gradually widening from base to basal 5/8, then narrowing to blunt apex. Anellus lobe 1/3 length of valva, distal 1/2 slightly narrowed, blunt at apex; apical bristle 1/4 length of anellus lobe, hooked. Juxta setose, with a hummock-like process. Vinculum slender, simple. Saccus large, subtriangular, apex blunt, exceeding tegumen pedunculus. Aedeagus with basal 1/2 dilated, sinuous distally, apex shortly curved upward.

Female genitalia ( Fig. 47E View FIGURE 47 ). Papillae anales short, moderately sclerotized, broadly covered with minute spines except anterior margin. Apophyses anteriores 3/4 length of apophyses posteriores. Tergum VIII shorter than sternum VIII, posterior margin slightly concave. Sternum VIII concave posteriorly, with anterior margin strongly produced in U-shape; medial sclerotization gradually narrowed toward ductus bursae, anterior 1/4 spatulate and slightly curved, reaching base of ductus bursae. Ductus bursae slightly longer than corpus bursae, with ductus seminalis arising from posterior 1/7. Corpus bursae elongate-obovate; signum at middle, semielliptical with a central ridge.

Variations. The forewing can be less covered with grey or fuscous scales, and it is rather creamy sometimes. The markings can also be indistinct.

Distribution. China (Guizhou).

Etymology. The species name is from Latin, gracilis (slender), referring to the slender forewing.