A review of the subgenus Delineatia Volynkin & Huang, 2019 of the genus Ammatho Walker, 1855, with descriptions of two new species from Taiwan and Vietnam (Lepidoptera, Erebidae, Arctiinae, Lithosiini) Author Volynkin, Anton V. Altai State University, Lenina Avenue, 61, RF- 656049, Barnaul, Russia. & National Research Tomsk State University, Lenina Avenue, 36, RF- 634050, Tomsk, Russia Author Wu, Shipher Biodiversity Research Center, Academia Sinica, No. 128, Sec. 2, Academia Rd., Nangang Dist., Taipei City 11529, Taiwan. shipher @ gmail. com; https: // orcid. org / 0000 - 0003 - 2264 - 7238 text Zootaxa 2020 2020-06-18 4801 2 237 250 journal article 21639 10.11646/zootaxa.4801.2.2 a1540ced-2e09-452a-bd37-aee70242bf23 1175-5326 3900426 C8430970-E584-4B98-B515-38CD47ADA90E Ammatho ( Delineatia ) trangchim Volynkin & Wu , sp. n. ( Figs 17, 18 , 29 , 34 ) urn:lsid:zoobank.org:act: D7970D67-72AE-46DF-BBCA-F9AEC0AB73AB Type material. Holotype ( Figs 17 , 29 ): male, “ III.2014 , Central Vietnam , Thua Thien-Hue Province , Annamite Mts, Bach Ma Mt., 1400m , leg. local collectors”, slide ZSM Arct. 2019-699 Volynkin (Coll. MWM / ZSM ). Paratypes . VIETNAM : 1 female , the same data as in the holotype , slide ZSM Arct. 2019-700 Volynkin (Coll. MWM / ZSM ) ; 6 females , the same data (Coll. CAV ) . Diagnosis. Forewing length is 15 mm in the holotype male and 16–18 mm in females. The new species can be easily distinguished externally from its closest relative A. sublucana by its broader forewing, pale candy body coloration (in A. sublucana those are intense crimson), pale candy forewing ground color with pale candy cilia (in A. sublucana the forewing is intense crimson with black cilia), pale red hindwing ground color and cilia (in A. sublucana the forewing is crimson with cilia black at apex and crimson along outer and anal margins), and slightly shorter radial strips in the postmedial area of forewing. Compared to members of the A. delineatia species-group, A. trangchim sp. n. can be recognized by its paler crimson coloration, evenly crimson cilia of both wings, and thinner postmedial line and radial strips in the postmedial area. The male genitalia of A. trangchim sp. n. differ from those of A. sublucana by their slightly shorter but medially broader uncus, slightly less elongated valva, longer and narrower apical thorn of the distal costal process directed more dorsally (in A. sublucana that is shorter and broader and directed distally), the well-developed trigonal subapical thorn of the distal costal process (in A. sublucana that is present as a short smooth protrusion), more angular distal end of the broad setose section of sacculus (in A. sublucana that is smoothly rounded), more massive distal saccular process, aedeagus being slightly more broadened distally, and more elongated and narrowed tip of the medial conical diverticulum (in A. sublucana that is shorter and broader). The female genitalia of A. trangchim sp. n. are similar to those of A. sublucana but differ by the narrower, crescent-shaped postvaginal plate (that is narrowly semilunar in A. sublucana ), shorter and posteriorly broader, wineglass-shaped antrum (that is narrowly conical in A. sublucana ), and slightly shorter spinulose area in the posterior section of corpus bursae. FIGURES 27–29. Ammatho spp.: male genitalia. Depositories of the specimens: 27—NHMUK (©); 28—CAV; 29—MWM/ ZSM. FIGURES 30–34. Ammatho spp.: female genitalia. Depositories of the specimens: 30, 32, 34—MWM/ZSM; 31—NHMUK (©); 33—CAV. Distribution . Central Vietnam ( Thua Thien-Hue Province : Annamite Range). Etymology . Trang Chim is the moon goddess in the traditional Vietnamese mythology.