Siccia seima, Volynkin & Černý, 2023

Volynkin, Anton V. & Černý, Karel, 2023, Siccia seima, a new species from Cambodia and Thailand (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Ecologica Montenegrina 69, pp. 10-16 : 11-15

Siccia seima sp. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:9880527B-0D26-4EA2-A844-FFD86678ECB8

( Figs 1–3 , 11 , 15 )

Type material. Holotype ( Figs 1 , 11 ): male, “ Cambodia, Mondolkiri Prov., | Seima Biodiversity Conservation | Area , between Seima and O’Rang, | 12°15'44[''] N 107°03'49 ['']E, 360 m, | 27–29. I. 2006 | leg. G. Csorba & G. Ronkay ” / “Slide | ZSM Arct. | 2019- 133♂ | A. Volynkin ” (MWM/ ZSM).

Paratypes. CAMBODIA: 1 male, the same data as in the holotype, gen. prep. No.: ZSM Arct. 2019- 132♂ (prepared by Volynkin) (MWM/ ZSM) . THAILAND: 1 female, Sakhon Nakhon [ Province ], Phy Pan NP, 320m, 17°05.767'N 102°59.91''E, 5–7.XI.2010, K. Černý leg., gen. prep. No.: AV3970 ♀ (prepared by Volynkin) ( CKC) ; 1 female, Chiang Rai [Province], 1090m, road 1150, km 17 from Wiang Pa Pao , 19°18'45''N 99°23'24''E, 27. V .2011, K. Černý leg., gen. prep. No.: AV3969 ♀ (prepared by Volynkin) ( CKC) .

Diagnosis. The forewing length is 8.5–9.0 mm in males and 9.5–10.0 mm in females. Siccia seima sp. n. ( Figs 1–3 ) is externally reminiscent of S. sordida Butler, 1877 ( Figs 4–6 ) and S. likiangensis (Daniel, 1951) ( Figs 9–10 ) and differs from the former species in the somewhat larger size, the broader forewing, the more pronounced transverse lines, the more elongate discal spot of the forewing, and the darker hindwing with a more diffuse discal spot. Compared to S. likiangensis , the new species is markedly smaller in size, and has shorter rami of the male antenna, intense blackish suffusion on the forewing in the antemedial and subterminal areas, and more intense brownish-grey suffusion on the hindwing postmedially. In the male genitalia, S. seima sp. n. ( Fig. 11 ) is distinguished from S. sordida ( Fig. 12 ) by the somewhat longer and broader phallus, and the longer and broader vesica bearing a longer area of scobination and a single long and robust cornutus whereas S. sordida has a row of 2–4 considerably smaller cornuti. Compared to S. likiangensis ( Fig. 14 ), the male genitalia of S. seima sp. n. has a somewhat longer and medially thicker uncus, a markedly shorter and less sclerotised ventral costal lobe, a shorter dorsal (apical) spur of the cucullus, a shorter and narrower distal saccular process, a considerably longer, broader and more medially curved phallus, and a substantially longer and broader vesica bearing a longer cluster of more robust scobination and a long and robust horn-shaped cornutus which is short thorn-shaped in the congener. The male genitalia structure of the new species is also similar to the externally dissimilar S. cinerea Bucsek, 2020 ( Figs 7, 8 , 13 ) but in S. seima sp. n., the uncus is shorter and medially thicker, the cucullus lacks the triangular dorsal process, the distal saccular process is shorter, the phallus is longer, broader and more curved, the vesica is longer, broader and bearing a longer cluster of more robust scobination and a markedly longer and thicker cornutus. The female genitalia of S. seima sp. n. ( Fig. 15 ) are distinguished from S. sordida ( Fig. 16 ) and S. cinerea ( Fig. 17 ) by the broader ductus bursae, the posterior section of the corpus bursae having a heavily sclerotised concave lateral plate on the left side, the globular anterior section of the corpus bursae (it is elliptical in both the congeners), and the distally broader and granulose appendix bursae. Compared to S. likiangensis ( Fig. 18 ), the female genitalia of the new species have a longer and broader ductus bursae, a well-developed and heavily sclerotised posterior section of the corpus bursae, a larger anterior section of the corpus bursae bearing a second ribbon-like signum ventrally, and a markedly longer, more helicoid and granulose appendix bursae.

Description. External morphology of adults ( Figs 1–3 ). Head off-white, suffused with black scales. Antenna pale brown, shortly bipectinate in male and filiform in female. Thorax off-white, suffused with black scales. Forewing ground colour of-white with black irroration. Pattern elements slate black, diffuse. Subbasal line interrupted into two spots: larger one on costa and smaller one medially. Antemedial area intensely suffused with slate black between vein R and anal margin. Antemedial line sinuous, dentate medially, dilated into trapezoidal spots on wing margins. Cell with medial round spot between antemedial and medial lines, and reniform discal spot. Medial line irregularly sinuous and dentate, strongly bent outward medially and strongly dilated into trapezoidal spot on costa. Postmedial line irregularly dentate, strongly bent outward medially, strongly dilated into trapezoidal spot on costa, and almost touching medial line at anal margin with medial area intensely suffused these lines. Subterminal line parallel postmedial one, diffuse, strongly dilated into large trapezoidal subapical spot on costa. Terminal line interrupted into spots between veins. Forewing cilia off-white with diffuse blackish spot medially. Hindwing and its cilia pale brownish-grey; discal spot semilunar, indistinct. Abdomen brownish-grey, male valvae covered with hair-like pale ochreous scales; female corethrogyne also pale ochreous. Male genitalia ( Fig. 11 ). Uncus cylindrical, almost straight, medially slightly dilated, distally tapered and with downcurved claw-shaped tip. Arms of tegumen strongly dilated posteriorly and fused in posterior third. Vinculum moreo к less equal in length to tegumen, with heavily sclerotised U-shaped saccus. Valva lobular, medially dilated and distally tapered. Costa with rounded lobe-like proximal ventral lobe. Cucullus with two thorn-like processes apically and ventrally, and short dorsal protrusion subapically. Sacculus narrow with short triangular distal process directed dorsally. Transtilla ribbon-like. Juxta weakly sclerotised, trapezoidal. Phallus gradually upcurved, with very short coecum. Vesica broad sack-like, with outer half covered with robust scobination and short lateral diverticulum basally bearing long and robust thorn-like cornutus. Basal plate of vesica ejaculatorius long, ribbon-like. Female genitalia ( Fig. 15 ). Papilla analis trapezoidal with rounded corners, weakly setose. Apophyses long and thin, apophysis posterioris ca. twice longer than apophysis anterioris. Ductus bursae sclerotised, dorso-ventrally flattened, funnel-like dilated posteriorly. Posterior section of corpus bursae weakly sclerotised, with heavily sclerotised concave lateral plate on left side, and elongate cluster of minute spinules on right side at base of appendix bursae. Anterior section of corpus bursae globular, membranous, with rugose ribbon-like signum ventrally and elliptical serrulate signum dorsally. Appendix bursae tubular, helicoid, covered with granuli, situated postero-laterally on right side, directed laterally.

Distribution. Cambodia (Mondolkiri Province) and Thailand (Sakhon Nakhon and Chiang Rai Provinces).

Etymology. The specific epithet is homonymic of the type locality. The name is a noun in apposition to the generic name.

Figures

Figures 1–10. Siccia spp.: adults. Depositories of the specimens: 1, 9 and 10 in MWM/ZSM; 2, 3, 5 and 6 in MWM/ZSM; 4 in NHMUK (©The Trustees of NHMUK); 7 in SNM (after Bucsek 2020); 8 in CKB (after Bucsek 2020).

Figures 11–14. Siccia spp.: male genitalia. Depositories of the specimens dissected: 11, 12 and 14 in MWM/ZSM; 13 in SNM (after Bucsek 2020).

Figures 15–18. Siccia spp.: female genitalia. Depositories of the specimens dissected: 15 in CKC; 16–18 in MWM/ZSM.