Acronicta (Acronicta) meghala, Volynkin & Saldaitis & Dvořák, 2023

Volynkin, Anton V., Saldaitis, Aidas & Dvořák, Marek, 2023, Acronicta meghala, a new species from Indochina (Lepidoptera: Noctuidae: Acronictinae), Ecologica Montenegrina 69, pp. 117-125 : 118-124

Acronicta (Acronicta) meghala sp. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:771F95E3-542F-424A-985D-1E200D6C2AB5

( Figs 1–4 , 13–15 , 21–23 )

Type material. Holotype ( Figs 1 , 13 ): male, “ 10–20.VIII.2014, | South Laos, | Champasak prov., | 27 km ENE of Pakse, | near Tad Fane waterfall, | 15°11'01.1''N 106°07'40.5''E, | 950m, local collector leg.” / “Slide | AV7429 ♂ | A. Volynkin ” ( WIGJ, ex CAV).

Paratypes. LAOS: 2 males, the same data as in the holotype, gen. prep. No.: AV7389 ♂ ( CAV) ; 1 male, Champasak Prov., Dong Hua Xao NBCA, camp near Nam Phak River , 15°58'N 105°55'E, 280m, 28– 29.III.1998, collected at light, O. Merkl & G. Csorba leg. ( HNHM) ; VIETNAM: 8 males, 3 females, XI.2012, Ngh ệ An Province, near Con Cuông, Pù Mát National Park , local collectors leg., gen. prep. Nos.: AV6892 ♂, AV7390 ♀, AV7430 ♂, AV7431 ♀ ( CAV) ; 1 male, Lào Cai Prov., 1800m, Fan-si-pan Mts , 14 km NW Sa Pa, 22°20'91.7''N 103°46'44.5''E, 29–30.VIII.1998, A. Kun leg. ( HNHM) ; 2 males, 4 females, Lào Cai Prov., 1250m, Sa Pa, Cat-Cat, Frontier Base Camp , 22°19'36.4''N 103°49'46.1''E, 26–28.VIII.1998, A. Kun leg. ( HNHM) ; 1 male, the same locality and collector as previous but 4–8.VIII.1998 ( HNHM) ; 2 males, 2 females, Lào Cai Prov., 1690m, Fan-si-pan Mt., Frontier Sat. Camp , 22°20'48.1''N 103°47'45.2''E, 24– 25.VIII.1998, A. Kun leg. ( HNHM) ; 1 female, [Hòa Bình Prov.] Moc Chau , 800m, 25.X.1986, collected on light near to and at the guest house, F. Mészáros, J. Oláh & T. Vásárhelyi leg. ( HNHM) ; 1 male, Ngh ệ An Prov., Pu Hoat Mts , 280m, 19°40.5'N 104°54.1'E, 23–24.X.1999, F. Kassai leg. ( HNHM) ; 1 female, the same data as previous but 30.XI.1999 ( HNHM) ; 3 males, Ngh ệ An Prov. , Pu Hoat Mts, Po Phuong, 280m, 19°38.442'N 104°58.302'E, 17.X.–29.XI.1999, F. Kassai leg. ( HNHM) ; 1 male, 3 females, the same data as previous (Coll. G. Ronkay, NHMW) ; 1 male, 1 female, Ngh ệ An Prov., Que Phong Distr. , Ban Khom, 280m, 19°40.5'N 104°54.1'E, 21–23.I.1999, G. Ronkay leg. (Coll. G. Ronkay, NHMW) ; THAILAND: 5 males, 4 females, Doi Inthanon, Mae Pan Waterfall Resort , 10–11.VIII.2009, 1135m, Sergey Murzin leg., gen. prep. Nos.: AV7387 ♂, AV7388 ♀ ( MDS) ; 1 male, Changwat Chiang Mai, Mt. Doi Inthanon, NP, 2300m, 7– 8.IX.1999, A. Szabó & Z. Czere (Coll. G. Ronkay, NHMW) ; 1 female, Chiang Mai Prov., 1800m, 4 km S of Kop Dong , 19°52'N 99°03'E, 06.XI.2002, B. Herczig & G. Ronkay leg. (Coll. G. Ronkay, NHMW) ; 1 female, Chiang Rai [Prov.], [W]iang Pa Pao , 14.VIII.[19]89 ( HNHM) ; 1 female, Chiang Mai [Prov.], Doi Suthep , 23.VIII.[19]89 ( HNHM) ; 1 male, Nan Prov., 5 km N of Ban Luang, 350m, between Pi Nai and Pi Tai , 18°56'N 100°27'E, 4.XI.2002, B. Herczig & G. Ronkay leg. ( HNHM) ; 8 males, the same data as previous (Coll. G. Ronkay, NHMW) ; 1 male, the same data as previous ( PGM) ; MYANMAR: 1 female, Tenasserim, Dawna Mts , 16°52'N 98°08'E, I.1996, Steinke & Lehmann leg. (Coll. G. Ronkay, NHMW) .

Diagnosis. Acronicta meghala sp. n. ( Figs 1–4 ) is externally very similar to A. major ( Figs 7–12 ) and differs only in the slightly shorter subbasal streak. The reliable identification requires the examination of the genitalia structures. Compared to A. maxima ( Figs 5, 6 ), the new species is somewhat smaller, has a somewhat less distinct forewing pattern, a markedly smaller reniform stigma, and smaller spots of the terminal line. The male genital capsule of A. meghala sp. n. ( Figs 13–15 ) is very similar to A. major ( Figs 16–19 ) and distinguished only by the subbasally broader uncus; from A. maxima ( Fig. 20 ) it differs in the longer distal section of the valva (in proportion to the tegumen-vinculum complex length). The phalli of the three species are alike. In the vesica structure, the new species can be distinguished from A. major by the larger lateral diverticulum, the slightly shorter ventral diverticulum, and the remarkably narrower distal diverticulum bearing a cluster of cornuti with slightly narrower bases. Unfortunately, the vesica of the only specimen of A. maxima available for examination was damaged and therefore was not spread fully. However, it differs from A. meghala sp. n. in the somewhat denser cornuti of the dorsal cluster, and the markedly smaller lateral diverticulum. In the female genitalia, A. meghala sp. n. ( Figs 21–23 ) differs from A. major ( Figs 24, 25 ) in the somewhat shorter ductus bursae, and the distally narrower appendix bursae directed more laterally. Compared to A. maxima ( Fig. 26 ), the female genitalia of the new species have a somewhat longer ductus bursae and a slightly larger corpus bursae.

Description. Adults ( Figs 1–4 ). Antenna filiform, brown. Head and thorax brownish-grey. Forewing ground colour grey or brownish-grey with brown suffusion. Basal dash black, reaching antemedial line, with short dash-like lateral branches. Subbasal area with two diffuse brownish-grey spots on costal margin. Antemedial line double, wavy, pale brown, diffuse. Orbicular stigma elliptical, with thin black margin. Reniform stigma edged with blackish scales and having intense fuscous suffusion along anterior margin. Medial line fuscous, diffuse, stretching outwards from costal margin to reniform stigma, bent outwards opposite cell, and stretching inwards along postmedial line. Postmedial area with blackish diffuse spot on costal margin medially. Postmedial line off-white with brownish suffusion and black outer margin, dentate on veins, broadly curved outwards in front of cell. Two long and thin, black longitudinal dashes cross postmedial line between veins M1 and M2, and Cu2 and A1. Terminal line black, interrupted into spots between veins. Cilia brownish-grey with black spots connected to those of terminal line. Hindwing ground colour pale greyish-ochreous with intense greyish-brown suffusion. Discal spot crescent-shaped, diffuse. Medial line thin and diffuse, sinuous at anal margin. Terminal band broad, diffuse, tapered towards to anal angle. Terminal line interrupted into fuscous spots between veins. Cilia pale greyish-ochreous with admixture of brown scales. Male genitalia ( Figs 13–15 ). Uncus robust, hook-like downcurved, apically pointed, covered with hair-like setae distally. Tegumen bell-shaped, with anteriorly tapered arms. Tuba analis narrow, with broad and heavily sclerotised scaphium. Vinculum shorter than tegumen, with thin arms, V-shaped. Valva lobular and apically rounded. Costa somewhat convex medially. Sacculus short, trapezoidal. Clasper shortly triangular, stretching along ventral margin. Harpe long (protruding beyond dorsal margin of valva), thorn-like, gradually tapered distally and apically pointed, somewhat curved medially. Juxta elongate shield-like. Phallus broad, dilated distally, with short and apically rounded coecum. Vesica broad, curved dorsally, with semiglobular lateral diverticulum, short conical dorsal diverticulum bearing elongate and sparse cluster of spine-like cornuti stretching from its tip along outer wall of vesica, and sack-like distal section with weak and rugose lateral sclerotisation and broad and elongate cluster of thin spike-like cornuti stretching from its tip towards base of vesica ejaculatorius. Female genitalia ( Figs 21–23 ). Papilla analis rectangular with rounded corners, setose. Apophyses long and thin, more or less equal in length. Ostium bursae funnel-shaped with membranous margins. Ductus bursae tubular and narrow, membranous, longitudinally rugose. Corpus bursae elongate sack-like, somewhat constricted medially, with rugose and posteriorly tapered posterior section bearing short conical diverticulum laterally at junction with appendix bursae. Appendix bursae large, sack-like, semi-globular distally, situated and directed postero-laterally.

Distribution. The new species is currently known from southern Laos (Champasak Province), northern Vietnam (Lào Cai, Nghệ An, and Hòa Bình Provinces), northern Thailand (Chiang Rai, Chiang Mai, and Nan Provinces), and Myanmar (Tenasserim Division). The records of A. maxima from Thailand, Vietnam and Myanmar ( Kononenko & Pinratana 2005) belong to A. meghala sp. n. The records of A. maxima from South China ( Kononenko & Pinratana 2005; Han & Kononenko 2010), and Northeast India and Nepal ( Hampson 1909; Hreblay & Ronkay 1998) require further clarification as there were no specimens available from those areas for the current study.

Etymology. The specific epithet is derived from the Greek ‘μεγάλο’ meaning ‘large’ and refers to the large size of the new species.

Figures

Figures 1–8. Acronicta spp.: adults. Depositories of the specimens: 1 in WIGJ (ex CAV); 2 and 4 in CAV; 3 in MDS; 5 and 6 in NHMUK (©The Trustees of NHMUK); 7 and 8 in ASV.

Figures 13–16. Acronicta spp.: male genitalia. Depositories of the specimens dissected: 13 in WIGJ (ex CAV); 14 in CAV; 15 in MDS; 16 in ASV.

Figures 21–26. Acronicta spp.: male genitalia. Depositories of the specimens dissected: 21 and 22 in CAV; 23 in MDS; 24 and 25 in ASV; 26 in NHMUK (©The Trustees of NHMUK).

Figures 17–20. Acronicta spp.: male genitalia. Depositories of the specimens dissected: 17–19 in ASV; 20 in NHMUK (©The Trustees of NHMUK).