Collitoptyx, Volynkin, 2023

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 : 61

Genus Collitoptyx gen. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:4AA0EC60-19C1-4622-A48C-354E747F2A88

Type species: Thysanoptyx incurvata Wileman & West, 1928, by present designation.

Diagnosis. Species of the new genus ( Figs 5, 6 ) are externally very similar to Thysanoptyx ( Figs 7, 8 ). The male genital capsule of Collitoptyx gen. n. ( Fig. 16 ) is clearly different from Thysanoptyx ( Fig. 17 ) by the slender and apically pointed uncus (it is apically bifurcate in Thysanoptyx ), the proximally narrower and elongate valva with a weakly sclerotised costa (in Thysanoptyx , it is heavily sclerotised, and also setose in most species), and the broad sacculus having an additional dorsal process in most species. The phallus of Collitoptyx gen. n. is equal in length to the tegumen-vinculum complex or shorter than it, whereas it is markedly larger in Thysanoptyx . The vesica of Collitoptyx gen. n. is more or less globular or elliptical, has one or two short diverticula, and bears a single spike-like cornutus distally, whereas it is elongate and with large diverticula bearing massive cornuti and sclerotised plates in Thysanoptyx . The male genital capsule of Collitoptyx gen. n. is also reminiscent of the externally dissimilar Collita Moore, 1878 ( Figs 9, 10 ) due to the presence of dorsal saccular processes, but in Collita ( Fig. 18 ), those processes are asymmetrical and often apically rounded or irregular (whereas they are symmetrical and apically pointed in the new genus). Additionally, compared to Collitoptyx gen. n., Collita has a thicker and heavily sclerotised uncus (it is dorso-ventrally flattened and weakly sclerotised in the new genus), an intravincular corema (absent in Collitoptyx gen. n.), and a heavily sclerotised apical process of the juxta, whereas the juxta of the new genus is flattened and weakly sclerotised. The phallus of Collitoptyx gen. n. is somewhat distally dilated whereas it is slightly distally tapered in Collita . The vesica of Collitoptyx gen. n. is globular or elliptical, membranous, having one or two small diverticula in certain species, and bearing a single spike-like cornutus, whereas in Collita , the vesica is sack-like, has larger diverticula, and bears broad clusters of scobination and several short thorn-shaped cornuti. In the female genitalia, Collitoptyx gen. n. ( Fig. 21 ) differs from Thysanoptyx ( Fig. 22 ) in the short and membranous ductus bursae (it is sclerotised in the similar genus), the posterior section of the corpus bursae having a large and sclerotised lateral protrusion (it is absent in Thysanoptyx ), and the vestigial appendix bursae, which is large and utricular in Thysanoptyx . Compared to Collita ( Fig. 23 ), the female genitalia of Collitoptyx gen. n. differ in the narrower ostium bursae, the markedly narrower and more weakly sclerotised ductus bursae, the posterior section of the corpus bursae having a large gelatinous protrusion, and the short and conical appendix bursae, which is strongly elongate and tubular in Collita .

Species grouping. The genus is hereby subdivided into two species-groups. The C. incurvata species-group is characterised in the diagnosis of the genus. The C. sordida species group comprises one described species (illustrated by Volynkin & Dubatolov (2017)) and differs from the C. incurvata species-group in the reduced dorsal saccular process, and the longer, hook-shaped distal saccular process.

Distribution. The genus is widely distributed from Nepal and Northeast India through northern Indochina and southern China to the island of Taiwan.

Etymology. The generic name is an aggregate of the genus-group names Collita and Thysanoptyx . Gender is feminine.

Remarks. The new genus comprises the species included by Volynkin & Dubatolov (2017) in the ‘ Thysanoptyx incurvata species-group’. The genus is currently under revision by Volynkin et al. (in prep.).

Figures

Figures 1–8. Lithosiina spp.: adults. Depositories of the specimens: 1, 3–8 in MWM/ZSM; 2 in NHMUK (©The Trustees of NHMUK).

Figures 13–16. Lithosiina spp.: male genitalia. Depositories of the specimens dissected: 13–15 in MWM/ZSM; 16 in NHMUK (©The Trustees of NHMUK).

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 9–12. Lithosiina spp., type species of the genera: adults. Depositories of the specimens: 9 in ANHRT; 10 in ZFMK (photo by S.-Y. Huang); 11 and 12 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.