Ammatho (Idopterum) wuchunshengi Huang, Volynkin & Wang, 2020

Huang, Si-Yao, Volynkin, Anton V., Wang, Min & Fan, Xiao-Ling, 2020, A new species of the subgenus Idopterum Hampson, 1894 of the genus Ammatho Walker, 1855 from China (Lepidoptera: Erebidae: Arctiinae: Lithosiini), with redefinition of the subgenus Idopterum, Zootaxa 4885 (2), pp. 271-276 : 273-276

Ammatho (Idopterum) wuchunshengi Huang, Volynkin & Wang sp. nov.

( Figs 1–2 , 7–8 )

Type material. Holotype: male, altitude 1700m, 19. VIII. 2018, Mt. Dawei , Pingbian Miao Autonomous County, Honghe Hani & Yi Autonomous Prefecture, Yunnan Province, P. R. China, leg. Si-yao Huang, slide ISY001 (Coll. SCAU) . Paratype: 1 male, same data as for the holotype, slide ISY002 (Coll. SCAU) .

Diagnosis. Adults of A. wuchunshengi sp. nov. are similar externally to those of A. ovale ( Figs 3–6 , 9–11 ), but A. wuchunshengi sp. nov. can be immediately distinguished from the latter by the broader forewing, more rounded basal dark shade and blackish pattern restricted to apical zone on hindwing, whereas in A. ovale the forewing is narrower, basal dark shade is more triangular-like and hindwing ground color is mostly pale brownish-black. The male genitalia capsule of A. wuchunshengi can be distinguished from A. ovale easily by the subapically broader uncus, the juxta with a medial dentate process, the shorter and basally thicker distal costal process, the better-developed basal costal process, the broader medial costal process, the shorter distal membranous lobe and the much shorter and broader distal saccular process, whereas in A. ovale the uncus is gradually narrowing towards tip, the medial process of juxta is smooth, the basal costal process is obsolete, the distal costal process is longer and basally narrower, the medial costal process is narrower, the distal membranous lobe is longer and the distal saccular process is much longer and slenderer. The aedeagus vesica structure of A. wuchunshengi sp. nov. differs clearly from that of A. ovale by the presence of an additional dorsally directed small diverticulum situated on the outer half of the main diverticulum and the cornuti on the surface of outer half of the main diverticulum being much smaller and more abundant in number (in A. ovale only the basal diverticulum presents and that dorsally directed diverticulum is absent, and the cornuti on the surface of outer half of the central main diverticulum being much larger and less in number).

Description. Male. Length of forewing is 10.5– 11 mm (11 mm in holotype). Antenna long, weakly ciliate, pale yellow in basal half and brownish black in distal half. Head covered by pale ochreous and white scales. Thorax covered by bright orange scales dorsally.Abdomen covered by pale yellowish white hair. Forewing broad, ground color white. Wing base is tinged with orange. Costa is black from base to one third of the length of forewing. Forewing pattern comprises of two dark brownish shades with different shape and tone. The basal dark shade is pale blackish brown and more or less oval, scattered with white scales. The outer dark shade is twice larger than the basal one and also scattered with white scales, colors gradually vary from pale brown at the base to darker brown at the marginal zone. Apex white. Cilia pure white. Hindwing ground color white. A diffuse blackish patch presented around apex. Cilia pure white.

Male genitalia. Uncus long, gradually expanding towards tip and abruptly narrowing at the apex. Tegumen triangular. Tuba analis moderately broad; scaphium thin and short, weakly sclerotized; subscaphium membranous. Juxta broad, plate-like, medially with a dentate bulge and laterally with smooth slender process. Saccus V-shaped. Valva gradually broadened towards distal end. Costa strongly sclerotized; basal lobe rounded and semi-oval; medial costal process short and broad basally, gradually narrowing towards tip; distal costal process varies from extremely long (holotype) to moderately long (paratype), blade-like and curved medially. Distal membranous lobe of valva varies from moderately long and broad to short and rather stout. Sacculus broad, strongly sclerotized and setose at the dorsal ridge; distal saccular process short and stout, triangular. Aedeagus long and slender. Vesica broad and oval-shaped, with a large cornuti field presenting at the junction of aedeagus and vesica; dorsal basal diverticulum conical; dorsal distal diverticulum digitate, about half of the width of the dorsal basal one; outer half of the main diverticulum covered by cornuti field and granulation; medial ventral diverticulum nearly semi-globular.

Female. Unknown.

Distribution. Currently only known from its type locality, Mt. Dawei in Southeastern Yunnan Province of Southwestern China.

Etymology. The specific epithet is dedicated to Dr. Chun-sheng Wu (IZCAS, Beijing) who kindly helped the senior author during his visit to the lichen moth collection housed in IZCAS.

Remarks. Although the genitalia of the holotype and paratype have some differences in the length of the distal costal process and distal membranous lobe of valva, we still consider these two specimens conspecific for they both share similar ground plan of distal saccular process and aedeagus vesica structure and at the same time differ greatly from those of I. ovale . Similar to what we found in the new species, the genitalia of A. ovale also show variation in the lateral process of juxta, width of distal membranous lobe of valva and length of distal saccular process (figs. 9–11), especially in regard of the male from Western Yunnan (figs. 3 & 9). However, we believe this individual should be identified as A. ovale for its genitalia ground plan, such as the length of distal saccular process and the size of the cornuti, still falls within the variation of that of typical A. ovale from Northern Thailand and Vietnam (figs 10–11). The visible differences are only due to individual variation commonly found across Lithosiini and the way of preparing genitalia slides, so we neither treat it as another new species nor hybrid between A. ovale and A. wuchunshengi sp. n..

Figures

FIGURES 1–6. Ammatho (Idopterum) spp. adults. 1, A. wuchunshengi sp. nov., holotype male, SW. China, Yunnan (SCAU); 2, A. wuchunshengi sp. nov., paratype male, SW. China, Yunnan (SCAU); 3, A. ovale, SW. China, Yunnan (SCAU); 4, A. ovale, N. Thailand, Chiang Mai (CKC); 5, A. ovale, N. Vietnam, Mt. Fansipan (MWM/ZSM); 6, A. ovale, holotype female, Myanmar, Bernardmyo. Scale=1 cm.

FIGURES 7–11. Male genitalia of Ammatho (Idopterum) spp. 7, A. wuchunshengi sp. nov., holotype, slide ISY001; 8, A. wuchunshengi sp. nov., paratype, slide ISY002; 9, A. ovale, slide ISY003; 10, A. ovale, slide MWM 31381; 11, A. ovale, slide MWM 31382.