Acronicta (Viminia) metaxantha ( Hampson, 1909 ), 2017

Volynkin, Anton V., Matov, Alexej Yu. & Han, Hui-Lin, 2017, On the taxonomy of the genus Acronicta (Lepidoptera, Noctuidae). IV. Acronicta digna species-complex, Zootaxa 4344 (1), pp. 189-194 : 193

Acronicta (Viminia) metaxantha ( Hampson, 1909) , stat. rev., bona sp.

( Figs 1–3 , 13, 14 , 16, 19 )

Acronycta metaxantha Hampson 1909 , Catalogue of the Lepidoptera Phalaenae in the British Museum, 8: 139, Pl. 126, fig. 17 (Type

locality: [East China, Zhejiang] Chia-kou-ho).

Type material examined. Syntype ( Fig. 1 ): ♂, printed label "Chia-Kou-Ho, 1700 ft., A.E. Pratt coll., July 1889 " / handwritten label " Acronycta metaxantha type male. Hmpsn." / printed label "Leech Coll. 1900–64 " / printed label with QR-code "BMNH(E) 1377134" / round white label with red ring "Type" (coll. NHMUK).

Other material examined. 1 ♂, China, Shaanxi, Taibai Shan , 33°53' N, 107°49' E, March 2000, 1500 m , leg. Local collector, ex coll. Victor Siniaev / Gen. 3027 / ex coll. A.V. Nekrasov (coll. ZISP); 1 ♀, China, Shaanxi, Taibai Shan, 33°53' N, 107°49' E, June , 1500–1800 m , leg. Siniaev & Plutenko / ex coll. A.V. Nekrasov (coll. ZISP); 2 ♂, 1 ♀, China, Shuangliu County, Sichuan Prov. , 20.vii.2010, Acr-001, Acr-004 , leg. GH Huang (coll. CGH); 2 ♂, same data (coll. NEFU).

Slides 0396 Matov, HGH089 Huang, hhl-3358, hhl-3359 Han (males); 0403 Matov (female)

Note. A. metaxantha has been erroneously synonymized with A. digna ( Butler, 1881) by Han & Kononenko (2010) on the basis of examination of a type specimen picture. Both taxa have more or less similar forewing pattern, but A. digna has whitish (spring generation ( Fig. 7 )) or grayish brown (late summer generation ( Figs. 4–6 )) hindwings, whereas metaxantha ( Figs. 1–3 ) has conspicuously yellow hindwings with dark border. Examination of genitalia of the specimens from China externally identical to metaxantha syntype ( Fig. 1 ) showed differences in the genitalia of both sexes from those of digna . For this reason, A. metaxantha is revived here as a distinct species.

Diagnosis. A. metaxantha ( Figs 1–3 ) is externally similar to A. lutea ( Fig. 8 ) and A. digna ( Figs. 4–7 ), but differs from the first one by the more brownish ground colour of forewings, the somewhat more distinct pattern, presence of dark narrow fields in hind parts of the medial and subterminal areas, and the more diffuse dark terminal band on hindwings; from A. digna it differs clearly by the somewhat narrower forewing with more rounded apex, the more brownish ground colour of forewings, the more diffuse pattern, the broader reniform stigma, the stronger dentate postmedial line with less whitish outer area, and the yellow ground colour of hindwings. The male genitalia of A. metaxantha ( Figs 13, 14 , 16 ) are very close to those of A. digna ( Figs 9–12 , 15 ), but differ by the aedeagus structure: in A. metaxantha the distal part of aedeagus is much broader than in A. digna , in A. digna the subbasal diverticulum has two large well developed lobes while the second lobe of A. metaxantha is very small or absent, distal cornuti on the vesica of A. metaxantha are much larger than those of A. digna . The female genitalia of the two taxa are very similar, but in A. metaxantha ( Fig. 19 ) the apophyses anteriores are shorter, the anterior part of ductus bursae near the connection with corpus bursae is broader, the corpus bursae is somewhat smaller.

Distribution. The species is known from central and eastern parts of China.

Figures

FIGURES 1 – 8. Acronicta spp.: adults. 1, A. metaxantha, ♂ syntype, W China (© NHMUK); 2, A. metaxantha, ♂, China, Shaanxi (ZISP); 3, A. metaxantha, ♂, China, Sichuan (CGH); 4, A. digna, holotype ♂, Japan, Yokohama (© NHMUK); 5, A. digna, syntype ♂ of Acronycta michael, Russian Far East (© NHMUK); 6, A. digna, neotype ♂ of Acronycta agnata, China, Hunan (ZFMK); 7, A. digna, ♂, spring form, Russian Far East, Khabarovsk Reg. (ZISP); 8, A. lutea, ♂, Russian Far East, Khabarovsk Reg. (ZISP).

FIGURES 9 – 14. Acronicta spp.: male genitalia. 9, A. digna, Japan, slide AV 2286 Volynkin; 10, A. digna, Japan, slide AV 2287 Volynkin; 11, A. digna, Russian Far East, Amur Reg., slide AV 1499 Volynkin; 12, A. digna, neotype of Acronycta agnata, China, Hunan, slide ZFMK Kononenko- 1850; 13, A. metaxantha, China, slide HHL- 3358 Han; 14, A. metaxantha, China, slide Acr- 004 Han.

FIGURES 15 – 19. Acronicta spp.: male aedeagus with diagnostic features marked (15, 16) and female genitalia (17 – 19). 15, A. digna, Japan, slide AV 2286 Volynkin; 16, A. metaxantha, China, slide HHL- 3358 Han; 17, A. digna, Japan, slide AV 2288 Volynkin; 18, A. digna, Russian Far East, Amur Reg., slide AV 1500 Volynkin; 19, A. metaxantha, China, Sichuan, gen. prep. H. - L. Han.