Tecmerium rectimarginatum, Teng & Wang, 2018

Teng, Kaijian & Wang, Shuxia, 2018, Genus Tecmerium Walsingham (Lepidoptera: Blastobasidae) new to China, with descriptions of two new species, Zoological Systematics 43 (4), pp. 420-428 : 426-427

Tecmerium rectimarginatum sp. nov. ( Figs 3 , 7 , 11 )

Diagnosis. Tecmerium rectimarginatum sp. nov. is similar to T. albafaciella ( Adamski, 2002) in the male genitalia by sharing a narrow gnathos, a juxta broadly concave in triangle on the anterior margin, and a sclerite of the phallus broadly curved and not bifurcate apically. It can be separated from T. albafaciella by the gnathos straight on both posterior and anterior margins, and the narrower proximal flange produced ventromedially and almost forming a right angle in the male genitalia. In T. albafaciella , the posterior margin of the gnathos is convex sub-semicircularly, and the broader proximal flange is broadly rounded ventromedially ( Adamski, 2002: fig. 6).

Description. Adult ( Fig. 3 ) forewing length 4.5–6.0 mm (n = 6). Head pale gray or grayish brown, scales tipped with grayish white. Antenna with scape grayish white on ventral surface; grayish brown on dorsal surface except part scales tipped with grayish white, anterior margin grayish white; pecten brown except grayish white at tip; flagellum dark brown, ciliated on ventral surface in male. Labial palpus brown, part scales tipped with grayish white; second segment grayish white at apex; third segment nearly as long as second, pointed apically. Haustellum gray. Thorax and tegula pale brown, mixed with grayish white tipped scales. Forewing pale grayish brown, scales tipped with grayish white; costa with three spots: first spot dark brown, sub-quadrate, at basal 1/3, second spot brown mixed with pale brown scales, rectangular, ranging from middle to distal 1/3, both extending to upper margin of cell respectively, third one dark brown, sub-triangular, extending from distal 1/4 to near upper corner of cell, gradually narrowed to before apex; discal, discocellular and tornal spots dark brown, tornal spot oval and connected with discocellular spot; preapical spot oval, brown mixed with dark brown scales; dorsum with a brown stripe before middle, obliquely extending to below discal spot; fringe grayish brown, intermixed with grayish white tipped dark brown scales. Hindwing and fringe pale grayish brown, becoming darker from base to apex. Legs with dorsal surface grayish white; ventral surface dark brown, part scales tipped with grayish white, all tibiae and tarsomeres grayish white at apex. Legs dark brown on ventral surface, with scales tipped with grayish white, grayish white on dorsal surface and at apices of all tibiae and tarsomeres.

Male genitalia ( Figs 7 , 11 ). Eighth sternum with posterior half weakly sclerotized medially, forming a sub-semicircular plate ( Fig. 11 ). Uncus broad at base, slightly narrowed to middle, almost uniform in width from middle to distal 1/4, gradually narrowed from distal 1/4 to apex, distal half setose and longitudinally keeled on ventral surface. Gnathos rectangular, posterior and anterior margins nearly straight; lateral arms narrow, basally fused with tegumen. Upper division of valva with basal 1/3 sub-quadrate, gradually narrowed from basal 1/3 to basal 2/3, distal 1/3 clubbed, rounded apically, distal 4/5 setose; proximal flange narrowly produced ventromedially and almost forming a right angle. Lower division of valva broad, subrectangular; apex bluntly rounded, setose, with a spine-like dorsoapical process curved inward apically; sacculus with basal 3/5 broad, approximately 1/3 width of valva, distal 2/5 equally narrow, distal half setose. Juxta irregularly rounded, weakly sclerotized medially, broad triangularly concave inward on anterior margin. Vinculum narrow laterally, median portion anteriorly extended sub-semicircularly, posteriorly with a small sclerotized sub-quadrate plate ( Fig. 7a ). Phallus nearly as long as valva, curved ventrad, dilated spherically at base; internal sclerite curved ventrad, pointed apically ( Fig. 7b ); anellus with a few microsetae.

Female. Unknown.

Material examined. Holotype ♂, Mt. Xiantai (38.12°N, 113.84°E; elev. 1200 m), Jingxing County, Hebei, China, 23 July 2000, coll. Haili Yu et al., slide No. TKJ17006. Paratypes (5♂). 1♂, same data as holotype ; 1♂, Suanzaoping Village (elev. 670m), Neiqiu County, Hebei, China, 29 July 2000, coll. Haili Yu et al.; 1♂, Mt. Pan (elev. 170 m), Ji County, Tianjin, China, 20 July 2004, coll. Houhun Li et al.; 1♂, Houshan (elev. 1244 m), Zijiaosuo, Jingdong County, Yunnan, China, 5 July 2013, coll. Shurong Liu, Yuqi Wang and Kaijian Teng ; 1♂, Jingpozhai (elev. 231 m), Nabang Town, Yingjiang County, Yunnan, China, 2 August 2013, coll. Shurong Liu, Yuqi Wang and Kaijian Teng.

Distribution. China (Hebei, Tianjin, Yunnan).

Etymology. The specific epithet of this species is derived from the Latin rect- (straight) and marginatus (margin), in reference to the straight anterior and posterior margins of the gnathos.

Figures

Figures 1–4. Male adults of Tecmerium spp. 1. T. yunnanense sp. nov., holotype. 2. T. scythrella. 3. T. rectimarginatum sp. nov., holotype. 4. T. malikuli. Scale bars=2.0mm.

Figures 7–8. Male genitalia of Tecmerium spp. 7. T. rectimarginatum sp. nov., paratype, slide No. TKJ17325 (a. Enlarged and unrolled vinculum, slide No. TKJ17012; b. enlarged apex of phallus, slide No. TKJ17325). 8. T. malikuli, slide No. TKJ17298 (a. Enlarged and unrolled vinculum, slide No. TKJ17401; b. enlarged apex of phallus, slide No. TKJ17298). Scale bars=0.2mm.

Figures 9–13. Male eighth sternum and female genitalia of Tecmerium spp. 9. T. yunnanense sp. nov., paratype, slide No. TKJ17316. 10. T. scythrella, slide No. TKJ17247. 11. T. rectimarginatum sp. nov., paratype, slide No. TKJ16352. 12. T. malikuli, slide No. TKJ17400. 13. T. yunnanense sp. nov., paratype, slide No. TKJ17348 (a. enlarged signum). Scale bars: 9–12, 13a = 0.2 mm; 13 = 0.5mm.