Tylostega longicornuta, Liu & Wang, 2019

Liu, Ping & Wang, Shuxia, 2019, Two new species of the genus Tylostega Meyrick, 1894 (Lepidoptera: Crambidae) from China, with a list of all the known species in the world, Zoological Systematics 44 (3), pp. 206-211 : 207-208

Tylostega longicornuta sp. nov. ( Figs 1 , 3‒4 )

Diagnosis. This species is similar to T. tylostegalis Du & Li, 2008 superficially, but it can be separated by the valva with a sub-rectangular projection medially and the dorsal margin of the sacculus without denticles; in T. tylostegalis , the valva has a small triangular projection medially and the dorsal margin of the sacculus bears denticles (Du & Li, 2008: fig. 8). This species is also similar to T. serrata Du & Li, 2008 in the shape of the valva, but it can be separated by the phallus with one cornutus and the hindwing with a black spot at apex and at distal 1/3 of dorsum respectively; in T. serrata , the phallus has two cornuti, and the hindwing lacks a black spot at apex and dorsum (Du & Li, 2008: fig. 12).

Description. Adult ( Fig. 1 ) wingspan 18.0‒20.0 mm. Head yellowish brown. Antenna yellow or yellowish white, male ventral cilia approximately as long as diameter of flagellomere. Labial palp with 1st segment yellowish white; 2nd segment with basal 2/3 yellowish white except fuscous on dorsal surface, distal 1/3 fuscous; 3rd segment fuscous. Maxillary palp with basal half yellowish white, distal half fuscous. Proboscis with scales at base yellowish white. Patagium, tegula and thorax yellow mixed with fuscous. Forewing ground color yellow, with diffused blackish brown scales, with blackish brown patch at base; antemedial line black, extending from basal 1/4 of costa excurved to middle of lower margin of cell, then incurved to basal 1/3 of dorsum; depression before discoidal stigma, covered with a small yellow flat scale-tuft mixed with black and gray on dorsal surface, with dense grey and black scale-like pecten on ventral surface in male; orbicular stigma in female black, at distal 1/3; discoidal stigma blackish brown; postmedial line black, extending from distal 1/3 of costa oblique outward to near middle of R 3+4, then oblique inward to near middle of M 2, thereafter arched outward to basal 1/3 of CuA 2, finally extending to distal 1/3 of dorsum; terminal domain blackish brown; black spots along terminal margin; cilia yellowish brown, slightly darker at base. Hindwing yellow, blackish brown at apex, with a black spot at base; discoidal stigma black; postmedial line black, extending from distal 1/3 of costa oblique inward to middle of M 2, thereafter arched inward to near basal 1/3 of CuA 2, finally excurved to above 1/3 of dorsum, connecting with black spot at distal 1/3 of dorsum; black spots along terminal margin; cilia yellowish brown, slightly darker at base. Abdomen yellow mixed with brown and blackish brown scales. Legs yellowish white except black at apices of femora, tibiae and each tarsomere.

Male genitalia ( Fig. 3 ). Uncus gradually narrowed from base to rounded apex, with height greater than basal width, setose along lateral margin of distal 4/5 and on dorsal surface of distal 1/5. Valva subparallel from base to basal 3/5, narrowed from basal 3/5 to rounded apex; median projection sub-rectangular, bearing dense denticles anteriorly, bifurcate distally; costa band-like, uniform from base to basal 3/4, gradually narrowed from distal 1/4 to apex, terminating before apex; sacculus concave at basal 1/4 dorsally, arched medially, slightly concave at distal 2/5, gradually narrowed from distal 1/4 to apex, terminating at distal 2/5 of valva on ventral margin. Saccus triangular. Juxta sub-trapezoidal, arched outward. Phallus about 4/5 length of valva, with one long, curved spine-like cornutus, slightly shorter than phallus.

Female genitalia ( Fig. 4 ). Apophyses anteriores approximately 2 times length of apophyses posteriores. Lamella antevaginalis U-shaped, posterior margin concave deeply to above anterior margin, anterior margin obtuse. Ductus burse curved outward at basal 1/3, distal half with small granules forming a longitudinal stripe. Corpus bursae oblong, widened anteriorly, not well divided from ductus bursae.

Type material. CHINA, Hainan: Holotype, ♂, Jianfengling (18.75°N, 108.87°E; elev. 810 m), Ledong County, 14 June 2018, leg. Ping Liu, Xia Bai & Shuai Yu, slide No. LP18045 . Paratypes. 1♂ 1♀, 11 August 2017, leg. Xia Bai, Ping Liu & Shuai Yu, slide No. LP17934 , same locality as holotype ; 2♂, Mingfenggu, Jianfengling , 8‒9 August 2017, others same as holotype ; 1♂, Tianchi, Jianfengling , 9 March 2016, leg. Qingyun Wang, Suran Li & Shengnan Zhao ; 1♀, Tianchi, Jianfengling , 7 August 2016, leg. Xia Bai, Shuonan Qian & Wanding Qi, slide No. LP18008 ; 1♂, Tianchi, Jianfengling , 17 July 2015, leg. Qingyun Wang, Suran Li & Mengting Chen ; 1♂ 1♀, Tianchi, Jianfengling, 15 Januarry 2016, leg. Kaijian Teng, Xia Bai & Mengting Chen ; 1♂, Jianfengling , 27 April 2014, leg. Tengteng Liu, Wei Guan & Xuemei Hu ; 3♀, Mt. Limu , 25 July 2014, leg. Peixin Cong, Linjie Liu & Sha Hu ; 3♂, Mt. Limu, 5 Januarry 2016, leg. Kaijian Teng, Xia Bai & Mengting Chen, slide Nos. LP17930 , L917931; 1♀, Bawangling , 23 April 2009, leg. Qing Jin ; 1♀, Bawangling , 6 April 2008, leg. Bingbing Hu & Haiyan Bai ; 1♀, Nankai Town, Yinggeling , 16 August 2016, leg. Xia Bai, Shuonan Qian & Wanding Qi ; 1♀, Hongkan, Yinggeling , 14 March 2016, leg. Qingyun Wang, Suran Li & Shengnan Zhao ; 1♀, Hongxin Village, Yuanmen Township, Baisha , 18 April 2014, leg. Tengteng Liu, Wei Guan & Xuemei Hu, slide No. LP17935 ; 1♂, Beida Town, Jianling Village, Wanning , 28 July 2008, leg. Bingbing Hu & Li Zhang, slide No. LP17932 ; 1♂ 3♀, Mt. Wuzhi , 23‒28 July 2016, leg. Xia Bai, Shuonan Qian & Wanding Qi, slide Nos. LP17933 ♂, LP18044 ♀; 1♀, Mt. Wuzhi , 6 July 2014, leg. Peixin Cong, Linjie Liu & Sha Hu ; 1♀, Shuiman Town, Mt. Wuzhi , 2 August 2016, leg. Xia Bai, Shuonan Qian & Wanding Qi ; 1♂, Chongtoumen, Shuiman Town, Mt. Wuzhi , 30 July 2013, leg. Haili Yu & Kaili Liu, slide No. LP18041 .

Distribution. China (Hainan).

Etymology. The specific name is derived from the Latin longi- and cornutus, referring to the rather long cornutus of phallus in male genitalia.

Figures

Figures 1–2. Tylostega spp., adult. 1. T. longicornuta sp. nov., male, holotype. 2. T. vittiformis sp. nov., male, holotype. Scale bars= 2.5mm.

Figures 3–6. Tylostega spp., genitalia. 3. T. longicornuta sp. nov., male genitalia, holotype, slide No. LP18045. 4. Ditto, female genitalia, paratype, slide No. LP18044. 5. T. vittiformis sp. nov., male genitalia, slide No. LP18007. 6. T. serrata Du & Li, 2008, female genitalia, slide No. LP17985. Scale bars: 3, 5=0.5mm; 4, 6=1.0mm.