Taxonomic review of the Thysanoptyx Hampson generic complex (Lepidoptera: Erebidae: Arctiinae: Lithosiini). II. The genus Thysanoplisna Volynkin with descriptions of seven new species from Vietnam and mainland China Author Volynkin, Anton V. text Zootaxa 2024 2024-09-09 5506 3 428 450 http://dx.doi.org/10.11646/zootaxa.5506.3.7 journal article 10.11646/zootaxa.5506.3.7 1175-5326 13747211 F7F39F20-07D0-434B-9DB7-160C19D519E5 Thysanoplisna monotona sp. nov. ( Figs 19, 20 , 47 , 62 ) Type material . Holotype ( Figs 19 , 47 ): ♂ , “N-Vietnam 1400m | [ Hòa Bình Province ] Mai-chau , Urwald [jungle] | 40km SE Moc-chau | 20.50’N 104.50’E [ 20°50'N 104°50'E ] | 07.–15.IV.1995 leg. | Sinjaev [ Sinyaev ] & EinhSamml [native collector]” | vertical inscription “ Museum Witt ” / “ Genitalpräparat | Heterocera | Nr. 35.958 | Museum WITT München ” (MWM/ ZSM ). Paratypes . VIETNAM : 13 ♂♂ , 10 ♀♀ , same data as holotype, gen. prep. Nos.: MWM 35.956 ( ♂ ), 35.957 , 35.959 ( ♀ ) (MWM/ ZSM ) . Diagnosis . The forewing length is 16.0–18.0 mm in males and 17.5–18.0 mm in females. Thysanoplisna monotona sp. nov. is vaguely reminiscent of the sympatric Th. minuta sp. nov. but differs clearly in the markedly larger size, the more unicolorous, brownish-grey forewing ground colour, the narrower medial spot of the forewing, and the considerably narrower suffused area on the hindwing, which stretches only along the costal and distal half of the outer margins. Compared to another large congener with a pale hindwing found in Northern Vietnam , namely Th. grandimacula sp. nov. , the new species has a narrower forewing with a more unicolorous, brownish-grey ground colour, a markedly shorter medial spot, and the intense brownish-grey suffusion along the costal and distal half of the outer margins of the hindwing. The male genitalia of Th. monotona sp. nov. are most reminiscent of the sympatric Th. minuta sp. nov. with its narrow phallus and the prominent basal diverticulum but the genital capsule of the new species is distinguished by the slightly broader vinculum, the somewhat distally narrower valva, and the thicker distal saccular process. The vesica of the new species differs from Th. minuta sp. nov. in the semiglobular basal diverticulum (it is trapezoidal in the congener), the broader dorsal subbasal diverticulum, the narrower distal section with a reduced dorsal medial diverticulum and the narrow, semiglobular ventral medial diverticulum displaced laterally, and the broader distal diverticulum bearing a markedly larger and more curved cornutus. In the female genitalia, Th. monotona sp. nov. is distinguished from Th. minuta sp. nov. by the broader and slightly posteriorly tapered ductus bursae, the posterior gelatinous enlargement of the corpus bursae having a more laterally prominent right side and bearing a larger sclerotised plate anteriorly, and the shorter, narrower and less laterally curved appendix bursae. Distribution . Northern Vietnam ( Hòa Bình Province ). Etymology . The specific epithet refers to the forewing ground colour of the new species, which is more unicolorous than in similar congeners. The name is a noun in the nominative singular in apposition.