Tecmerium yunnanense, 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 : 421-424

Tecmerium yunnanense sp. nov. ( Figs 1 , 5 , 9, 13 )

Diagnosis. Tecmerium yunnanense sp. nov. is similar to T. scythrella ( Sinev, 1986) in the male genitalia by sharing a wider rectangular gnathos, a juxta broadly concave in triangle on the anterior margin, and a sclerite of the phallus bifurcate apically. It can be separated from T. scythrella in the male genitalia by the eighth sternum with posterior 1/3 sclerotized ( Fig. 9 ), and the two apical processes of the sclerite of the phallus unequal in length ( Figs 5, 5b ); in the female genitalia by having a signum ( Fig. 13 ). In T. scythrella , the eighth sternum is sclerotized in posterior half ( Fig. 10 ), the two apical processes of the sclerite of the phallus are equal in length ( Figs 6, 6b ) in the male genitalia; and the signum is absent in the female genitalia ( Sinev, 1986: fig. 18).

Description. Adult ( Fig. 1 ) forewing length 5.5–6.5 mm (n = 6). Head grayish brown, mixed with dark 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, 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 slightly shorter than second, pointed apically. Haustellum grayish brown. Thorax and tegula brown, mixed with pale gray or grayish white tipped scales. Forewing pale grayish brown, scales tipped with grayish white, distal half mixed with brown and dark brown scales, apex dark brown; humeral patch dark brown; costa black, intermixed with grayish white tipped scales, with two costal spots respectively extending to upper margin of cell: one dark brown, subquadrate, at basal 1/3, another brown mixed with dark brown scales, elongate oval, ranging from middle to distal 1/3; fold with a narrow rectangular dark brown spot before middle; discal, discocellular and tornal spots dark brown, tornal spot oval and connected with discocellular spot; dorsum with a brown stripe before middle, extending obliquely to below discal spot; fringe brown, intermixed with grayish white tipped dark brown scales, dark brown around apex. 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.

Male genitalia ( Figs 5 , 9 ). Eighth sternum with posterior 1/3 weakly sclerotized, forming a sub-rectangular plate ( Fig. 9 ). Uncus broad at base, slightly narrowed to a rounded apex, distal half setose and longitudinally keeled on ventral surface. Gnathos rectangular, slightly convex on posterior margin, straight on anterior margin; lateral arms narrow, basally fused with tegumen. Upper division of valva sub-quadrate in basal half, clubbed in distal half, rounded apically, setose in distal 4/5; proximal flange narrow lunate. Lower division of valva broad, sub-rectangular; apex rounded, setose, with a finger-like dorsoapical process; sacculus with basal 2/3 broad, approximately 1/2 width of valva, distal 1/3 equally narrow, distal 3/5 setose. Juxta triangular, concave inward broad triangularly on anterior margin. Vinculum narrow laterally, median portion anteriorly extended sub-trapezoidally, posteriorly with a small sclerotized circular plate ( Fig. 5a ). Phallus approximately 1.5 times length of valva, curved ventrad, dilated spherically at base; internal sclerite curved ventrad, bifurcate at apex, forming two spine-like processes unequal in length ( Fig. 5b ); anellus with a few microsetae.

Female genitalia ( Fig. 13 ). Apophyses posteriores approximately two times length of apophyses anteriores. Eighth segment with both sternum and tergum nearly straight on posterior margin, setose in posterior half; sternum concave triangularly and tergum concave semicircularly on anterior margin. Seventh sternum and tergum nearly straight on posterior margin. Ostium bursae placed at middle of intersegmental membrane between seventh and eighth segments. Ductus bursae approximately three times length of corpus bursae, constricted at basal 2/7 near inception of ductus seminalis, distal 1/7 gradually broadened towards corpus bursae; internal wall with granules from basal 1/3 to distal 1/7 on one side, with dense granules in entire distal 1/7. Corpus bursae rounded, with granules on internal wall; signum elongate oval, weakly sclerotized, with three heavily sclerotized triangular plates transversely ( Fig. 13a ).

Material examined. Holotype ♂, Qiunatong Village (28.10°N, 98.57°E; elev. 1767 m), Bingzhongluo Town , Gongshan County, Nujiang State, Yunnan, China, 16 June 2017, coll. Kaijian Teng et al., slide No. TKJ17342. Paratypes (4♂ 1♀). 1♂ 1♀, 14‒17 June 2017 , others same as holotype; 2♂, Taiyanghe Nature Reserves (elev. 1450 m), Yunnan, China, 22 May‒ 11 June 2014, coll. Zhenguo Zhang ; 1♂, Mt. Weibao (elev. 2244 m), Weishan County, Yunnan, China, 23 July 2013, coll. Shurong Liu, Yuqi Wang and Kaijian Teng.

Distribution. China (Yunnan).

Etymology. The specific epithet of this species is derived from the type locality, Yunnan.

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 5–6. Male genitalia of Tecmerium spp. 5. T. yunnanense sp. nov., paratype, slide No. TKJ17317 (a. Enlarged and unrolled vinculum, slide No. TKJ17342; b. enlarged apex of phallus, slide No. TKJ17317). 6. T. scythrella, slide No. TKJ17109 (a. Enlarged and unrolled vinculum, slide No. TKJ17218; b. enlarged apex of phallus, slide No. TKJ17218). 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.