Miltochrista bachma Volynkin & Derzhinsky, 2020

Volynkin, Anton V. & Derzhinsky, Yevgeniy A., 2020, Miltochrista bachma, a new species from southern Vietnam (Lepidoptera, Erebidae, Arctiinae), Ecologica Montenegrina 35, pp. 123-128 : 124-128

Miltochrista bachma Volynkin & Derzhinsky , sp. nov.

( Figs 1–3 , 9, 10 , 15 )

https://zoobank.org/ urn:lsid:zoobank.org:act:F29932B8-689F-4E13-83C1-77270A33B10E

Type material. Holotype ( Figs 1 , 9 ): male, “S. [C] Vietnam, Bach- Ma Nat. Park 1200m, 16°10’N 107°54’E, 26.VII.–6.VIII.1996, leg. Sinjaev [Sinyaev] & Afonin, ex coll. A. Schintlmeister ” / “Slide ZSM Arct. 2019- 754♂ A. Volynkin ” (Coll. MWM/ ZSM).

Paratypes: 2 females with the same data as for the holotype, slide ZSM Arct. 2019-755 Volynkin (Coll. MWM/ ZSM); 1 female, 3–7.IV.2014, Central Vietnam, Thừa Thiên- Huế Province , Annamite Mts, Bạch Mã National Park, 1400m, leg. local collector (Coll. CAV) ; 2 males, 2 females, 13.VIII.2019, Central Vietnam, Th ừa Thiên- Hu ế Province, Annamite Mts , B ạch Mã National Park, 1250m, 16°11’34’’N 107°51’12’’E, edge of tropical forest, Ye.A. Derzhinsky leg., slides AV5887 and AV5888 (males) Volynkin (Coll. CAV) .

Diagnosis. The new species ( Figs 1–3 ) is similar to M. testata ( Figs 4–6 ), but can be easily distinguished by its more shortly ciliate male antenna, slightly less elongate forewing apex, rose forewing coloration (in M. testata that is brick red in male and pale brick red in female), and pure rose male hindwing (in M. testata that is black with rose basal area and anal margin). The male genital capsule of the new species ( Figs 9, 10 ) differs clearly from that of M. testata ( Figs 11, 12 ) by the evenly narrow uncus (in M. testata that is broadened subapically), the more heavily setose subscaphium, the shorter juxta lacking a basal medial concavity (that is present in M. testata ), the broader and more rectangular vinculum (in M. testata that is narrower and U-shaped), the valva of uniform width (in M. testata that is broadened distally), the costa being narrower apically and not protruding to the distal lobe of valva, the conspicuously narrower distal lobe of valva (‘cucullus’), the slightly broader sacculus, and the slightly more robust and elongate distal saccular process. The aedeagus of the new species is conspicuously shorter and narrower than that of M. testata . The vesica of M. bachma sp. nov. is conspicuously shorter and narrower than that of M. testata , has the broad and bilobate largest ventral diverticulum (in M. testata that is conical and strongly elongate), and the conspicuously smaller, hook-shaped distal cornutus (that is very large and straight in M. testata ). The female genitalia of M. bachma sp. nov. ( Fig. 15 ) differ from those of M. testata ( Fig. 16 ) by the calyculate ostium bursae with a heavily sclerotized margins (whereas in M. testata there is a large rectangular antrum), the shorter and narrower membranous anterior section of the ductus bursae, the narrower corpus bursae bearing the elliptical signum (in M. testata that is round and slightly larger) and lacking a sclerotized lateral plate with spines and a sclerotized dentate posterior plate (both are present in M. testata ), and the much shorter and narrower appendix bursae. The male genital capsule of the new species is also reminiscent of that of the recently described M. lyclenoides ( Figs 7, 8 , 13, 14 ), but differs by the juxta lacking a basal medial concavity, the valva being not broadened distally with the distal part of the costa not protruding to the distal lobe of valva. However, despite the similarity of the genital capsules, the male vesica structure and the female genitalia of the new species and M. lyclenoides are fundamentally different.

Description

External morphology of adults ( Figs 1–3 ). Forewing length 8.5– 9 mm in males and 9.5– 10 mm in females. Male antenna ciliate, female antenna filiform. Sexual dimorphism weakly expressed: female slightly larger than male only. Head rose with a black dot on frons. Thorax rose with four black dots. Abdomen brown with admixture of rose scales. Forewing ground color rose, pattern black. Basal line represents two dots. Subbasal area with large subbasal dot and series of various sized short longitudinal strokes broadened distally. Subbasal part of costa edged with black. Antemedial line arcuate and W-like zigzagged medially. Medial line oblique, nearly straight. Postmedial line strongly loop-like curved around the cell and strongly regularly zigzagged on veins. Discal spot comma-like. Subterminal line parallel the postmedial line, strongly loop-like curved around the cell, interrupted into row of spots which are thin, stroke-like along the costa. Terminal line thin, entire. Cilia brown. Hindwing monotonous pale rose. Male genitalia ( Figs 9, 10 ). Uncus narrow, evenly curved, apically pointed. Tuba analis moderately broad; scaphium very weakly sclerotized, thin; subscaphium represents broad setose area. Tegumen moderately short and narrow. Transtillae fused, moderately broad. Juxta short, trapezoid, moderately sclerotized. Vinculum robust, rectangular with rounded corners. Valva elongate, relatively narrow, with nearly parallel margins. Costa narrow, slightly convex subapically, without processes. Distal lobe of valva elongate, distally narrowed, rounded apically. Sacculus moderately broad, distal saccular process strongly elongate, narrow but robust, slightly curved dorsally, with pointed tip. Aedeagus elongate, nearly straight, with slightly broadened proximal end. Vesica short, membranous, with one small subbasal diverticulum; large, nearly sack-like bilobate largest diverticulum situated medio-ventrally with the smaller lobe being granulated; and short round granulated distal diverticulum bearing short hook-like cornutus on broad base. Distal plate of vesica short and moderately broad. Female genitalia ( Fig. 15 ). Papilla analis broad, rectangular with rounded corners. Apophyses long and thin, equal in length. Ostium bursae moderately broad, its ventral margin edged with horseshoe-shaped sclerotized plate; dorsal part of subostial area of ductus bursae weakly granulated. Ductus bursae very short, narrow, membranous. Corpus bursae pear-shaped, membranous, with elliptical weakly dentate signum. Appendix bursae short, conical, membranous, situated posteriorly.

Distribution. The new species is known from its type locality, Bạch Mã National Park in central Vietnam only.

Etymology. The specific epithet refers to the type locality.

Figures

Figures 1–8. Miltochrista spp., adults. Depositories of the specimens: 1 and 3–6 in MWM/ZSM; 2 in CAV; 7 and 8 in CKC

Figures 9–12. Miltochrista spp., male genitalia. Depositories of the specimens: 9 and 11 in MWM/ZSM; 10 and 12 in CAV.

Figures 13–16. Miltochrista spp., male (13) and female (14–16) genitalia. Depositories of the specimens: 13 and 14 in CKC; 15 and 16 in MWM/ZSM.