Siccasura , a new genus for the Afrasura numida (Holland, 1893) species-group, with descriptions of six new species (Lepidoptera: Erebidae: Arctiinae: Lithosiini)

The present paper contains the description of a new genus Siccasura gen. nov. established for the members of the Afrasura numida (Holland, 1893) species-group. A review of all currently known taxa is provided, including the descriptions of six new species: S. kongo sp. nov. (DRC), S. sosta sp. nov. (Ivory Coast, Liberia, Gabon, Congo and CAR), S. hollandi sp. nov. (Gabon, Congo and DRC), S. transtillata sp. nov. (Cameroon), S. morettoi sp. nov. (Ivory Coast and Liberia), and S. spatulata sp. nov. (Guinea, Ivory Coast, Liberia, Nigeria, Cameroon and Gabon). A lectotype for Miltochrista numida Holland, 1893 is designated. All taxa are illustrated in 34 colour and 37 black and white diagnostic figures.


Introduction
Afrasura numida (Holland, 1893) was described from Gabon and has been considered a species widely distributed in western and central Africa (Durante 2009). However, examination of the copulatory organs of randomly selected specimens from various localities has revealed that A. numida comprises a complex of several cryptic species with confusingly similar external appearances but substantial differences in genitalia morphology. Further detailed studies of a large series of specimens resembling A. numida shed light on the existence of a further six mostly sympatric and hitherto undescribed species. As the genitalia of these species bear a number of diagnostic characters which cannot be assigned to the genus Afrasura Durante, 2009 or with any other genera, it is necessary to establish a new genus for A. numida and its congeners. The new genus Siccasura gen. nov. described in this paper currently contains seven species, six of them described Remark. The species of the new genus are confusingly similar in external habitus and at the same time vary in size, forewing colouration and pattern even within the same population rendering the identification impossible based exclusively on external features. Reliable identification of the Siccasura species in all cases requires the examination of the genitalia.
Description. External morphology of adults . Small moths with forewing length 6-8.5 mm in males and 7-9.5 mm in females. Sexual dimorphism limited: females slightly larger than males. Antennae of both sexes sparsely ciliate. Body ochreous-yellow, thorax with two black dots. Forewing ground colour ochreous-yellow with intense pink suffusion in medial and postmedial areas, transverse lines dark grey. Subbasal dot small and rounded. Antemedial line broad consisting of two lines and strongly undulating. Medial line sinuous, thin connected with postmedial line at costal and ventral margin and with antemedial line in the cell. Postmedial line wide, curved in the costal third, inner margin irregularly zigzagged, outer margin diffuse. Subterminal area with several diffuse black dots of different sizes. Discal spot reniform. Costa and cilia yellow. Hindwing pale ochreous-yellow but may be slightly pinkish. Medial line indistinct represented by a weak grey suffusion at costa. Terminal area with several diffuse dark spots of various sizes. Cilia as ground colour. Male genitalia . Uncus long, thin, dorso-ventrally flattened and apically rounded. Tuba analis broad, scaphium thin. Tegumen relatively short, narrow and weakly sclerotized. Vinculum short and broad U-shaped. Juxta may be dorso-ventrally swollen or flattened, triangular or shieldlike. Valva elongate with well-developed ventro-distal process and cucullus. In certain species, valvae asymmetrical expressed by different length of left and right valvae and configuration of the left and right sacculus and costa. Distal section of costal margin densely covered in spines of variable sizes or may be smooth in certain species. Cucullus well-developed, membranous, elongate and apically pointed. Ventrodistal process of valva long, narrow, heavily sclerotized and may be nearly straight or strongly curved. Sacculus wide, relatively short, terminating before the base of ventro-distal process. Aedeagus relatively short and narrow with short but laterally dilated coecum. Vesica broad with several small diverticula, a wide granulated or spinulose area, a heavily sclerotized basal plate but without distal plate. Basal plate covered in several tiny denticles. Female genitalia . Papillae anales trapezoidal with rounded corners and weakly setose. Apophyses long and thin. Membrane between 8 th segment and papillae anales weakly granulated. 7 th segment heavily sclerotized, tergite and sternite laterally fused, sternite with short anterioventral fold. In certain species 7 th segment with dorso-lateral pockets and subostial lobes or sclerotized crests ventrally. Ostium bursae with sclerotized margins fused with 7 th sternite, aperture positioned posteriorly. Dorsal plate of posterior section of ductus bursae present in all species, short, reaching the posterior or middle third of ductus bursae. Postvaginal plate of various shapes in different species-groups. Antevaginal plate present only in S. spatulata and is horseshoe-shaped. Ductus bursae short, tubular, membranous, with spinulose scobination anteriorly or anterio-laterally, continuing into the posterior section of the corpus bursae where it widens. Corpus bursae elliptical, with two rounded or ribbon-like weakly sclerotized, spinulose signa. Appendix bursae membranous, conical, apically rounded and projecting postero-laterally.
Distribution. The genus is widespread in western and central Africa. Etymology. Siccasura is an aggregate of the two generic names Siccia and Asura. The name refers to the vague similarity of the spotted wing pattern and the asymmetrical male genitalia of certain Siccasura species to those of Siccia.

The S. numida species-group
Diagnosis. The male genitalia of the species-group  are characterized by the combination of the following features: (1) the intertranstillar membrane is enlarged, weakly sclerotized and rugose; (2) the valva is elongate, with an almost straight costal margin; (3) the cucullus is of moderate size, its costal margin is smooth or finely spinulose; (4) the sacculus is elongate and tapering distally; (5) the ventro-distal process of the valva is moderately long, slightly tapering distally, rounded apically and curved inwards, the gap between it and the cucullus is relatively narrow; (6) the vesica bears a large and heavily sclerotized basal plate covered in tiny denticles. In the female genitalia (Figs 55-59), the 7 th abdominal segment has a deep subostial incision and well-developed dorso-lateral pockets, the postvaginal plate is very small and weakly sclerotized, and the ductus bursae is straight.
Siccasura numida (Holland, 1893  Remarks. Holland (1893) described Miltochrista numida based on both sexes without specifying the number of syntype specimens. As several externally undistinguishable species of Siccasura occur sympatrically in Gabon, the designation of a lectotype of M. numida is necessary in order to stabilize the nomenclature.
Diagnosis. The forewing length is 7-8 mm in males and 7-9.5 mm in females. The male genital capsule is easily recognized by the densely spinulose costal margin of the cucullus and the asymmetrical valvae. The left valva is longer and wider than the right one, having a larger ventro-distal process and an extensive cluster of short but robust spines on the sacculus which is either absent or consisting of only a few spines on the right sacculus. The male and female genitalia of S. numida are most similar to those of S. kongo, the distinctive characters are discussed under the diagnosis of the latter species.
Distribution. The species is known from Ghana (Durante 2009, fig. 54), Cameroon (Strand 1912a, partim), Gabon (Holland 1893) and reported here for the first time from the Republic of the Congo, Ivory Coast, Liberia and Guinea. Due to the lack of any external distinctive characters of the Siccasura species, all previous records of 'numida' (Aurivillius 1904;Hampson 1900;Strand 1912a (partim) Diagnosis. The forewing length is 7.5-8 mm in males and 8.5 mm in the female. The male genital capsule of S. kongo is similar to that of S. numida but the cucullus is less dentate, the ventro-distal processes of the valvae are longer and thicker and the left sacculus bears a much smaller cluster of short spines. The basal plate of the vesica of S. kongo bears smaller denticles and the subbasal diverticulum of the vesica is markedly wider compared to those of S. numida. The female genitalia of S. kongo are very similar to those of S. numida but are distinguished by the anteriorly wider dorsal plate of the posterior section of the ductus bursae, the fully spinulose anterior section of the ductus bursae (it is covered in spinules only laterally in S. numida) and the smaller signa bursae.
Distribution. The new species is currently known from two localities in North Kivu and Tshopo Provinces of the Democratic Republic of the Congo. The record of 'Asura numida' from North Kivu by Kiriakoff (1963) probably refers to S. kongo.
Diagnosis. The forewing length is 7-8 mm in males and 8-9 mm in females. The male genital capsule of S. sosta is reminiscent to that of S. numida but can easily be distinguished by the wider valva, the somewhat wider sacculus and the cluster of short spines which are situated on the right sacculus (it is positioned on the left sacculus in S. numida). The valva costa is distally pointed, reaching only the base of the cucullus without marginal dentation, while in S. numida it stretches to the tip of the cucullus and finely spinulose. The costa of the left valva bears a conspicuous, rounded subbasal lobe in S. sosta, a character which is absent in S. numida. Additionally, the V-shaped juxta of the new species is flattened dorso-ventrally whereas it is dorso-ventrally swollen and triangular with a wide but short basal depression in S. numida. Compared to S. numida, the vesica of S. sosta has a longer basal plate, a broader main chamber and a much wider and longer membranous distal diverticulum which is granulated in its congener. The female genitalia of S. sosta are distinguished from those of S. numida by the absence of the large and swollen subostial ventral lobes, the markedly shorter and narrower lateral pockets of the 7 th abdominal segment and the considerably shorter ventral fold of the 7 th sternite. In the new species, the dorsal sclerotized plate of the distal section of the ductus bursae is shorter and wider and the signa bursae are smaller.
Distribution. Siccasura sosta is widespread in western and central Africa and currently known from Ivory Coast, Liberia, Gabon, Republic of the Congo and Central African Republic.  Etymology. 'Sosta' is the Latin transliteration of the Greek word 'σωστά' meaning 'right'. The specific epithet refers to the presence of a diagnostic cluster of spines on the right sacculus. Volynkin & László,44,45,59) Type material. Holotype (Figs 11,44): male, "Gabon, 430m, Mikongo (Rougier), Monts de Cristal (Secondary Forest), 0°29'47"N, 11°10'42"E, 28.vii.-12.viii Paratypes (54 males, 3 females in total). GABON: 17 males, 1 female, with the same data as in the holotype, unique numbers: ANHRTUK 00111221, 00137796, 00137808, 00138966, 00138967, 00138969, 00155624, 00155625, 00155628, 00156184-00156186, 00156188-00156191, 00156192, 00156197, gen. slide Nos.: AV6178, AV6180 (males), AV5946 (female); 26 males, same data but collected by actinic light trap, unique numbers: ANHRTUK 00110926, 00110927, 00110958, 00138773, 00138781, 00138782, 00138784-00138786, 00138788-00138790, 00139165, 00142024, 00152730, 00152731-00152733, 00158171, 00158173, 00158174, 00162693, 00162715, 00162717, 00162719, 00163155, gen. slide Nos.: AV6172, AV6173, AV6179, AV5938, AV5937; 10 males, 1 female, same data but collected by MV light trap, unique numbers: ANHRTUK 00110994, 00165233, 00165234, 00165236, 00165273, 00165502, 00165513, 00165613, 00167802, 00167815, 00168043, 00192293, 00192557, 00192730, gen. slide Nos. Diagnosis. The forewing length is 7-8 mm in males and 7-8.5 mm in females. The genital capsule of S. hollandi is most similar to that of S. sosta based on the pointed distal section of the valva costa reaching only the base of the cucullus and lacking a dentation. The new species can easily be distinguished from S. sosta as well as from the other species of the S. numida species-group by its symmetrical valvae with the right sacculus lacking a cluster of spines. The ventro-distal process of the valva of the new species is longer than in S. sosta, the juxta is considerably shorter and the intertranstillar membrane is markedly longer and wider. In comparison with S. sosta, the vesica of S. hollandi is distinguished by the more rounded basal plate, the narrower main chamber covered in thinner spinules, the presence of a large lateral diverticulum and the tapering distal diverticulum which is apically wider and more rounded in S. sosta. The female genitalia of the two species are distinguished by the shorter 7 th abdominal segment with shorter lateral pockets, as well as the considerably shallower subostial incision of the 7 th sternite in S. hollandi. The corpus bursae of the new species is considerably narrower and medially constricted with a wide postmedial area lacking scobination, whereas that of S. sosta is sack-like and evenly covered in spinules except for the area at the base of the appendix bursae. Additionally, the appendix bursae of S. hollandi is globular and positioned ventro-laterally while it is conical and situated laterally in S. sosta.

Siccasura hollandi
Distribution. The new species is currently known from Gabon, the Republic of the Congo and the Democratic Republic of the Congo (Tshopo Province).
Etymology. The species is named after Dr William Jacob Holland (1848Holland ( -1932 an outstanding American lepidopterist and paleontologist, a former director of the Carnegie Museums of Pittsburgh and author of countless Lepidoptera taxa including the type species of the genus Siccasura.

The S. transtillata species-group
Diagnosis. The male genitalia of the species-group (Fig. 46) are similar to those of the S. numida speciesgroup but differ by the configuration of the transtillae which are fused into a rectangular medio-ventral plate bearing two elongate lobe-like processes projecting posteriorly which are densely covered in tiny denticles distally. The cucullus of the species-group is considerably smaller and the sacculus is shorter, basally wider and more tapering distally than in the S. numida species-group. Additionally, the ventro-distal process of the valva is somewhat dilated apically, while it is slightly tapering in the S. numida species-group. The female genitalia of the S. transtillata species-group (Fig. 60) are characterized by the very broad subostial depression of the 8 th abdominal segment (which is much narrower in the S. numida species-group), the large heavily sclerotized and densely spinulose postvaginal plate (which is very small and weakly sclerotized in the S. numida species-group), and the medially curved ductus bursae which is straight in the S. numida species-group. The signa bursae of the S. transtillata species-group are ribbon-like while those are rounded in its congeners. Volynkin & László,sp. nov. (Figs 15,16,46,60) Type material. Holotype (Figs 15, 46) Diagnosis. The forewing length is 8.5 mm in the holotype male and 9-9.5 mm in females. Although Siccasura transtillata has somewhat more elongate forewings in both sexes than in other congeners but owing to the substantial intraspecific variability of the Siccasura species, the adequate identification requires the examination of the genitalia morphology. The male genital capsule of the new species is most similar to that of S. hollandi but can easily be recognized by the presence of the well-developed transtillar processes, the considerably longer and wider, shield-like juxta (it is V-shaped in S. hollandi), the basally broader and distally tapering valva with a conspicuously smaller cucullus and the markedly broader ventro-distal process of the valva. Additionally, compared to S. hollandi, the new species has an apically somewhat dilated uncus (it is apically pointed in S. hollandi), a shorter tegumen, a medially slightly convex costal margin and a broader sacculus. The aedeagus of S. transtillata is slightly curved medially while it is nearly straight in S. hollandi. The vesica of the new species differs from that of S. hollandi by its elongate basal plate (it is rounded in the latter species), the absence of a lateral diverticulum and the considerably weaker granulation of the main chamber which is covered in tiny but heavily sclerotized spinules in S. hollandi. The female genitalia of S. transtillata differ from those of S. hollandi and other congeners by their very broad subostial area of the 7 th sternite, the substantially broad postvaginal plate densely covered in tiny spinules (it is short and elliptical in the S. numida species-group and X-shaped in the S. morettoi species-group), and the much broader ostium bursae. The ductus bursae of S. transtillata is medially curved and heavily scobinated while those of the other congeners are straight and weakly scobinated. Additionally, the signa bursae of the new species are ribbon-like while those of the other congeners are rounded.
Etymology. The specific epithet refers to the well-developed transtillar processes, which are unique in the genus.

The S. morettoi species-group
Diagnosis. The male genitalia (Figs 47-50) are distinguished from those of the other species-groups by the following features: (1) the intertranstillar membrane is short and weak, it is enlarged, sclerotized and rugose in the S. numida species-group, while in the S. transtillata species-group the transtillae are medially fused forming a plate with two well-developed distal processes; (2) the distal section of the costal margin of the valva is strongly curved, thickened and densely covered in short but robust spines; (3) the cucullus is conspicuously large and well separated from the ventro-distal process of the valva; (4) the sacculus is relatively short, its dorsal margin is parallel with while its distal margin is perpendicular to the ventral margin of the valva; (5) the ventro-distal process of the valva is robust, long, directed distally, dilated apically; (6) the basal plate of the vesica is considerably smaller than in the other congeners. The female genitalia of the species-group (Figs 61, 62) are also very characteristic and differ from those of the two other groups by the following features: (1) the 8 th abdominal segment lacks a subostial depression and the dorsolateral pockets but bears two pairs of ventral crests; (2) the edge of the ostium bursae is heavily sclerotized and fused with the postvaginal plate whereas it is membranous in the two other groups; (3) the postvaginal plate is more or less X-shaped, strongly constricted medially, somewhat goblet-shaped, whereas it is platelike in the two other groups. Volynkin & László,47,48,61)

Etymology.
The new species is dedicated to Mr Philippe Moretto, a specialist in Scarabaeinae and one of the collectors of the type series, who has over the years undertaken many entomological surveys throughout Ivory Coast.