Siccia Walker, 1854

Volynkin, Anton V., 2023, Contribution to the knowledge of the genus Siccia Walker (= Aemene Walker, syn. n.) in the Afrotropics with descriptions of seventy-three new species, three new subspecies, and a check-list of Asiatic taxa of the genus (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Ecologica Montenegrina 64, pp. 1-184 : 13-14

Genus Siccia Walker, 1854

Siccia Walker, 1854 , List of the Specimens of Lepidopterous Insects in the Collection of the British Museum, 2: 539 (Type species: Siccia caffra Walker, 1854 , by subsequent designation by Kirby (1892)).

= Aemene Walker, 1854 , List of the specimens of lepidopterous insects in the collection of the British Museum, 2: 541 (Type species: Aemene taprobanis Walker, 1854 , by monotypy), syn. nov.

= Melania Wallengren, 1863 , Wiener entomologische Monatschrift, 7 (5): 145 (Type species: Lithosia nigropunctata Wallengren, 1860 (a junior subjective synonym of S. caffra ), by subsequent designation by Hampson (1900)), a junior homonym of Melania Lamarck, 1799 (Mollusca).

= Panassa Walker, 1865 , List of the specimens of lepidopterous insects in the collection of the British Museum, 32: 607 (Type species: Panassa cingalesa Walker, 1865 (a junior synonym of A. taprobanis ), by monotypy), syn. nov.

= Autoceras Felder , in Felder & Rogenhofer, 1874, Reise der österreichischen Fregatte Novara um die Erde in den Jahren 1857, 1858, 1859 unter den Behilfen des Commodore B. von Wüllerstorf-Urbair. Zoologischer Theil, 2 (2): pl. 106, fig. 24 (Type species: Autoceras grammophora Felder, 1874 (a junior synonym of A. taprobanis ), by monotypy), syn. nov.

= Parasiccia Hampson, 1900 , Catalogue of Lepidoptera Phalaenae in the British Museum, 2: 407 (Type species: Aemene maculifascia Moore, 1878 , by original designation), syn. nov.

= Hyposiccia Hampson, 1900 , Catalogue of Lepidoptera Phalaenae in the British Museum, 2: 406 (Type species: Aemene amnaea Swinhoe, 1894 , by original designation), syn. nov.

Diagnosis. Species of the genus are small moths, most of which have pale off-white, greyish or brownish forewing ground colour (rarely, it is ochreous, yellow, orange or blackish-brown), and a pattern consisting of black or brown spots and diffuse transverse lines. Many species of the genus are externally similar to each other which, along with intraspecific variability, makes correct identification difficult and requiring the examination of the genitalia structures. The genitalia configurations of members of the genus are diverse and species can be subdivided into numerous species-groups characterised by variously modified structures of the copulatory organs of both sexes.

The male genital capsule of the genus is distinguished from the similar Palaeosiccia Hampson, 1900 ( Figs 279, 280 , 257 , 530 ) by the slender uncus (it is medially swollen in Palaeosiccia ), the long, thick and distally rugose scaphium which is more or less equal in length to the uncus (it is thin, short and terminating with a setose plate in Palaeosiccia ), and the membranous anellus, which is sclerotised in Palaeosiccia . The phallus of Siccia is evenly sclerotised whereas it is dorsally membranous in Palaeosiccia . The vesica of Siccia is membranous and bears diverticula, cornuti or areas of scobination or granulation whereas the vesica of Palaeosiccia has no diverticula or armature but bears broad areas of sclerotisation making its eversion problematic.

The female genitalia of the genus are diverse in configuration but have corpus bursae bearing broad areas of spinulose scobination, sclerotised plates, elongate signa or clusters of robust spines whereas that of Palaeosiccia is membranous bearing only a small elliptical or circular cornutus.

Description. External morphology of adults. Male antenna ciliate, serrate or bipectinate, female antenna ciliate. Body and forewing ground colour from off-white or pale brown to orange or blackish-brown, in many species suffused with grey or blackish scales. Forewing pattern black or blackish-brown, consisting of spots and diffuse transverse lines, latter usually interrupted into spots. In certain species forewing pattern reduced to a few or even one spot (usually discal one). Hindwing from off-white without pattern to blackish-brown, in most species extensively suffused with grey or brown. Discal sport and interrupted terminal line present in certain species but diffuse. Female abdomen with corethrogyne. Male genitalia. Uncus almost straight, elongate and slender, more or less cylindrical, somewhat dilated medially or proximally and with tiny claw-shaped tip. Scaphium thin but heavily sclerotised and distally rugose, as long as uncus or somewhat shorter. Arms of tegumen weakly sclerotised, posteriorly dilated and fused. Peniculus present and bearing cluster of setae in certain group. Vinculum shorter than tegumen and with short U-shaped or rectangular saccus. Valvae diverse in shape, from elongate and narrow to strongly proximally dilated, in certain groups asymmetrical or proximally connected by commissure. Costa with ventral lobe of various shapes and sizes, smooth or bearing processes or setae, and situated proximally or medially. Distal section of costa (called in the present paper ‘cucullus’) separated from the distal membranous lobe, heavily sclerotised in most species-groups, and bearing one or several processes of various shapes. Sacculus narrow, smooth in most groups but sometimes bearing setae or processes on its dorsal surface. Distal saccular process present in certain groups and diverse in its shape and size. Distal membranous lobe of valva present in certain groups, sometimes fused with ventral margin of cucullus. Phallus cylindrical, in certain groups distally dilated or/and with carina bearing thorns or clusters of denticles. Vesica membranous with diverticula of various shapes and sizes and, in certain groups, bearing cornuti of various shapes and/or fields of graniculi or spinules. Distal plate of vesica (basal plate of vesica ejaculatorius) long and slender, well-sclerotised. Female genitalia. Papilla analis weakly sclerotised and setose, rectangular or trapezoidal. Ovipositor short. Apophyses elongate and thin. Ostium bursae relatively broad. Postvaginal area with lateral subostial sclerotised lobes of various shapes bearing scales of corethrogyne. Postvaginal and antevaginal plates present in certain groups. Ductus bursae various in length and sclerotisation, in certain groups membranous or forming antrum, or vestigial. Corpus bursae sack-like or pyriform, bearing sclerotised plates, signa of various shapes and sizes, and, in many groups, densely covered with minute spinules. Appendix bursae situated postero-laterally, laterally or anterio-laterally, in most species more or less conical but in certain groups tubular and helicoid, or vestigial.

Distribution. Species of the genus are distributed from the Afrotropics through the Arabian Peninsula to the Oriental and eastern Palaearctic realms reaching New Guinea in the east.

Molecular data. The topologies from the dataset of 297 COI-5P sequences inferred by BI and ML analyses were mostly congruent. Due to its better resolution, the BI tree was chosen for illustration in this paper ( Figs 1–3 ). The pairwise distances between morphospecies varied greatly in different species-groups and were in the range of 1.56–14.54%. Most of the taxa included in the analyses were recovered as monophyletic with intraspecific divergences in the range of 0–2.19%. However, a few morphospecies ( S. faucaria , S. carinata , S. synthetia , S. punctipennis , etc.) varied intraspecifically (the divergences between different populations were in the range of 2.51–5.46%) and were recovered as polyphyletic, while three morphospecies ( S. megista , S. foya and S. chilambwe ) appeared paraphyletic with the latter two species being mixed with each other ( Fig. 1 ). The phenomenon of poly- and paraphyly in COI trees has been discussed by Mutanen et al. (2016). As no morphological differences can be found between such populations, they were treated in the present paper as belonging to the same species.

The grouping below was based mostly on morphology.

Figures

Figure 1. Phylogenetic tree of the genus Siccia from Afrotropics recovered from the BI analysis of COI barcodes.

Figure 2. Continuation from Fig. 1 of phylogenetic tree of the genus Siccia from Afrotropics recovered from the BI analysis of COI barcodes.

Figure 3. Continuation from Figs 1 and 2 of phylogenetic tree of the genus Siccia from Afrotropics recovered from the BI analysis of COI barcodes.

Figures 263–280. Siccia spp. (263–278) and Palaeosiccia punctata (279, 280), adults. Depositories of the specimens: 263, 264, 267, 269, 273–275, 277, and 280 in ANHRT; 265, 266, 268, 272, and 279 in NHMUK (©The Trustees of NHMUK); 270 and 276 in MfN; 271 in NHRS (©NHRS, photo by T. Malm); 278 in AKW.

Figures 240–262. Siccia spp., adults. Depositories of the specimens: 240 in NHRS (©NHRS, photo by T. Malm); 241 and 243 in NHMUK (©The Trustees of NHMUK); 242 in AKW; 244–246 in MWM/ZSM; 247–262 in ANHRT.

Figures 526–530. Siccia spp., female genitalia. Depositories of the specimens dissected: 526, 527, 529 and 530 in ANHRT; 528 in AKW.