Thysanoptyx Hampson, 1894

Volynkin, Anton V., 2023, On the taxonomy of the genus Thysanoptyx Hampson with descriptions of two new genera and a new species from Vietnam (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Ecologica Montenegrina 69, pp. 54-63 : 62

Genus Thysanoptyx Hampson, 1894

Type species: Lithosia tetragona Walker, 1854 , by original designation.

Diagnosis. The male genitalia of the genus ( Fig. 17 ) are characterised by the combination of the following features. (1) The uncus is short and apically bifurcate. (2) The valva is short and broad (in proportion to the tegumen-vinculum complex). (3) The costa is heavily sclerotised. (4) The phallus is long and broad (in proportion to the genital capsule size). (5) The vesica is large, has long and broad diverticula, and bears massive cornuti and heavily sclerotised plates. The female genitalia of Thysanoptyx ( Fig. 22 ) are vaguely reminiscent of those of Thysanoplisna ( Fig. 20 ) but distinguished by the lack of the large gelatinous protrusion of the posterior section of the corpus bursae, which is typical of the similar genus.

Species grouping. The genus is subdivided into two species-groups established by Volynkin & Dubatolov (2017): the T. tetragona species-group comprises species with a short distal saccular process, whereas the distal saccular process of the T. oblonga species-group (illustrated by Volynkin & Dubatolov (2017)) is elongate, and the general shape of the valva is similar to Thysanoplisna gen. n., Indalia , and Manulea .

Distribution. The genus is widespread from South India and Himalaya through Indochina to Sundaland.

Figures

Figures 17–19. Lithosiina spp.: male genitalia of the type species of the genera. Depositories of the specimens dissected: 17 in NHMUK (©The Trustees of NHMUK); 18 in ANHRT; 19 in MWM/ZSM.

Figures 20–24. Lithosiina spp.: female genitalia of the type species of the genera. Depositories of the specimens dissected: 20–22 in NHMUK (©The Trustees of NHMUK); 23 in ANHRT; 24 in MWM/ZSM.