Micralarctia dudai, Saldaitis & Volynkin & Hacker, 2021

Saldaitis, Aidas, Volynkin, Anton V. & Hacker, Hermann H., 2021, Micralarctia dudai, a new species from Socotra Island, Yemen (Lepidoptera: Erebidae: Arctiinae), Ecologica Montenegrina 46, pp. 61-66 : 62-65

Micralarctia dudai sp. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:DE86CFC3-ABB4-458E-8DD0-DEC72EDA2462

( Figs 1, 2 , 5, 8 , 9 )

Type material. Holotype ( Figs 1 , 5 ): male, “ N. Sokotra Island , Ayheft valley 12.01.2010. Saldaitis leg.” / “Slide AV6484 ♂ A. Volynkin ” ( WIGJ).

Paratypes: YEMEN: 3 males, 1 female, same data as in the holotype, gen. prep. No.: AV6485 (prepared by Volynkin) (female) ( ASV, GMF-B & WIGJ) ; 1 male, N Socotra Island , top of Ayheft valley, 17.i.2010, Saldaitis leg. ( GMF-B) ; 1 male, h- 500m, Socotra Isl. , Ayhft riv. valley, 25.xi.2008, Saldaitene & Saldaitis leg. ( ANHRT) ; 1 male, NE Socotra Island, Wadi Difarroha , North side, 19.i.2010, Saldaitis leg., gen. prep. No.: Hacker 24735 ( ASV) ; 1 female, E Socotra island , Dishaall loc. (Shey), 16.i.2010, Saldaitis leg., gen. prep. No.: Hacker 24736 ( WIGJ) .

Diagnosis. The new species ( Figs 1, 2 ) clearly differs externally from other congeners ( Figs 3, 4 ; also illustrated by Watson (1989): figs 43–48) in its pale brown body and wings colouration and the more diffuse forewing markings. The male genital capsule of M. dudai sp. n. ( Fig. 5 ) is most similar to that of M. stictographa Hacker, 2016 ( Fig. 6 ) known from the continental part of Yemen. However, compared to M. stictographa , the valva of the new species is wider basally and somewhat more dilated distally, the apical process of the valva is narrower, the ventral process of the valva is somewhat wider, and the subapical crest of the valva is wider and longer. Additionally, the uncus of the new species is somewhat narrower apically than in M. stictographa . The phallus of M. dudai sp. n. bears somewhat larger spines distally than that of M. stictographa . Since the female of M. stictographa is unknown, we compare the female genitalia of the new species ( Fig. 8 ) to other species of the genus (illustrated by Watson (1989): figs 126, 132–135). Compared to its congeners, the female genitalia of the new species have a markedly longer ductus bursae and a wider and longer postvaginal plate.

Description. External morphology of adults ( Figs 1, 2 ). Forewing length 15–17 mm in males and 19–20 mm in females. Male antenna bipectinate with short branches, female antenna filiform. Sexual dimorphism limited: female somewhat larger than male and having slightly more distinct wing markings. Head and thorax pale brown. Forewing ground colour pale brown with slight dark brown suffusion. Forewing markings dark brown, diffuse. Basal spot round, small. Antemedial line zigzagged, interrupted into spots of various sizes. Medial line angled on vein Cu, with almost straight posterior section interrupted into tree elongate spots of various lengths. Discal spot consisting of two pairs of short dash-like spots at bases of upper discocellular and M3 veins. Postmedial line smoothly curved outwards between Cu2 and R veins, disappearing at costal margin. Subterminal line zigzagged, interrupted into short longitudinal double dashes on veins. Terminal line interrupted into transverse dashes between veins. Cilia pale brown. Hindwing pale brown, somewhat paler than forewing, with dark brown markings. Discal spot broad, semilunar, medially interrupted in male. Subterminal line interrupted into four diffuse spots of more or less rectangular shape. Terminal line represented by one or two spots at apex. Abdomen dark brown with ochreous rings. Male genitalia ( Fig. 5 ). Uncus broad, more or less triangular with convex lateral margins and trapezoid tip, dorso-ventrally swollen and down curved, basally fused with narrow membranous tuba analis. Tegumen short with wide arms. Vinculum equal in length to tegumen, with V-shaped saccus. Valva lobe-like, dilate distally, curved inwards. Distal process of valva elongate, narrowly triangular and apically rounded. Ventral process of valva broad, triangular and apically rounded, curved inwards. Subapical crest broad, rounded. Juxta broad, almost rectangular with somewhat concave posterior and convex anterior margins. Phallus tubular, narrow, with two clusters of short but robust dentation distally. Carina short, triangular. Vesica tubular proximally and sack-like distally, curved dorsally, with cluster of short spine-like cornuti of various sizes medially and semi-globular diverticulum distally bearing spinulose scobination. Female genitalia ( Fig. 8 ). Papilla analis trapezoid with rounded corners, weakly setose. Apophyses elongate and thin, equal in length, apophysis anterioris somewhat wider basally than apophysis posterioris. Ostium bursae broad. Postvaginal plate broad, heavily sclerotised and swollen, with convex posterior margin. Antevaginal plate broad, heavily sclerotised, horseshoe-shaped, with rugose lateral margins fused with 8 th abdominal segment. Ductus bursae elongate, dilated posteriorly, dorso-ventrally flattened, heavily sclerotised with thin gelatinous lateral margins. Corpus bursae membranous, subdivided into two sections by medial constriction. Posterior section of corpus bursae sack-like; anterior section teardrop-shaped. Appendix bursae positioned postero-laterally on left side, conical basally, twisted medially and tubular distally, with teardrop-shaped bulla apically.

Distribution. The new species is endemic to Socotra Island where it is local and was found only in three localities with similar vegetation. Most of the specimens were collected in the Ayhft Valley, one of the most fertile localities on Socotra with subtropical rainforest and a species-rich flora comprising ca. 70% of all known species from the island ( Fig. 9 ).

Etymology. The species is dedicated to Mr Juozas Dûda, founder and director of the World Insect Gallery (Joniškis, Lithuania).

Figures

Figure 9. North of Socotra Island, Ayhft Valley, the type locality of Micralarctia dudai sp. n. (photo by A. Saldaitis).

Figures 1–4. Micralarctia spp.: adults. Depositories of the specimens: 1 in WIGJ; 2 in GMF-B; 3 in HH/ZSM; 4 in ANHRT.

Figures 5–8. Micralarctia spp.: male (5–7) and female (8) genitalia. Depositories of the specimens dissected: 5 in WIGJ; 6 in HH/ZSM; 7 in ANHRT; 8 in GMF-B