Thysanoplisna minuta, Volynkin, 2024

Volynkin, Anton V., 2024, 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, Zootaxa 5506 (3), pp. 428-450 : 433-435

Thysanoplisna minuta sp. nov.

( Figs 17, 18 , 46 , 61 )

Type material. Holotype ( Figs 17 , 46 ): ♂, “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. 36.038 | Museum WITT München ” (MWM/ ZSM).

Paratypes. VIETNAM: 13 ♂♂, 5 ♀♀, same data as holotype, gen. prep. No.: MWM 36.039 (♀) (MWM/ ZSM) .

Diagnosis. The forewing length is 13.0– 13.5 mm in males and 14.5–15 mm in females. Thysanoplisna minuta sp. nov. is the smallest species of the genus characterised by the intense brownish-grey suffusion on the hindwing medially and distally.The only species having similarly intensely suffused hindwing is Th.suffusa sp. nov., from which Th. minuta sp. nov. can be distinguished by the smaller size, the narrower forewing, and the broader suffused area on the hindwing. Additionally, the male of Th. minuta sp. nov. lacks the longitudinal postmedial ochreous androconial stripe, which is characteristic of Th. suffusa sp. nov. The male genital capsule of the new species has the narrowest valva in the species-group. Additionally, compared to Th. suffusa sp. nov., Th. minuta sp. nov. has a U-shaped vinculum, which is rather rectangular in the congener. The phallus of the new species is shorter and narrower (in proportion to the genital capsule) than in Th. suffusa sp. nov. In the vesica, Th. minuta sp. nov. differs from Th. suffusa sp. nov. in the narrower and trapezoidal basal diverticulum (it is semiglobular in the congener), the markedly shorter and narrower distal section of the vesica having a utricular distal diverticulum (it is rounded in Th. suffusa sp. nov.) and a narrower and trilobate ventral medial diverticulum (it is unilobate in the congener), and the smaller and claw-like curved cornutus of the distal diverticulum, which is straight and blade-shaped in Th. suffusa sp. nov. The vesica of Th. minuta sp. nov. is most reminiscent of Th. grandimacula sp. nov. but differs clearly in the longer and trapezoidal basal diverticulum (it is semiglobular in the congener), the narrower dorsal and shorter ventral subbasal diverticula, the smaller and unilobate dorsal medial diverticulum (it is bilobate in Th. grandimacula sp. nov.), and the shorter and trilobate ventral medial diverticulum (it is bilobate in the congener). Additionally, the cornutus of Th. minuta sp. nov. is markedly shorter, thinner and less curved than in Th. grandimacula sp. nov. The female genitalia of Th. minuta sp. nov. are distinguished from Th. suffusa sp. nov. by the anteriorly narrower ductus bursae having nearly parallel lateral margins (it is anteriorly dilated in the congener), the narrower posterior gelatinous enlargement of the corpus bursae with a less laterally protruding left side bearing a narrow sclerotised plate (absent in Th. suffusa sp. nov.), the larger signum bursae, and the longer appendix bursae. Compared to Th. grandimacula sp. nov., Th. minuta sp. nov. has a narrower ductus bursae with nearly parallel lateral margins (it is posteriorly tapered in the congener), a narrower posterior gelatinous enlargement of the corpus bursae, and a more laterally curved appendix bursae. The detailed comparison with another similar species, Th. monotona sp. nov. is provided below in the diagnosis of the latter.

Distribution. Northern Vietnam (Hòa Bình Province).

Etymology. The Latin ‘minutus’ means ‘small’ and the specific epithet refers to the small size of the new species. The name is an adjective in apposition to the genus name.

Figures

FIGURES 17–24. Adults of Thysanoplisna spp. The specimens are deposited in MWM/ZSM.

FIGURES 45–48. Male genitalia of Thysanoplisna spp. The specimens dissected are deposited in MWM/ZSM.

FIGURES 56–61. Female genitalia of Thysanoplisna spp. Depositories of the specimens dissected: 56 and 57 in NHMUK (©The Trustees of NHMUK); 58–61 in MWM/ZSM.