Ammatho (Striatella), Volynkin & Huang, 2019

Huang, Si-Yao, Volynkin, Anton V., Wang, Min & Fan, Xiao-Ling, 2020, Three new species of the genus Ammatho Walker, 1855 from China and Indochina (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Zootaxa 4809 (3), pp. 582-592 : 583-586

Subgenus Striatella Volynkin & Huang, 2019

Ammatho (Striatella) — In: Volynkin, Huang & Ivanova, 2019, Ecologica Montenegrina 26: 20, figs 13, 14, 110, 166. Type species: Lithosia hypoprepioides Walker, 1862 , by original designation.

Diagnosis. Most of the members of this subgenus have whitish or yellowish coloration with blackish pattern resembling some species of Miltochrista Hübner, [1819] with some exceptions. However, male and female genitalia of Striatella are very similar to those of Ammatho s. str. The male genitalia of Striatella are characterized by the entire, shield- or plate-like juxta, distal membranous lobe of valva short and not so well separated, and the vesica of aedeagus which has no large ventral diverticulum but bearing several small subdiverticula. The female genitalia of Striatella are characterized by the more robust spinulose scobination of corpus and appendix bursae. In addition, in most species of Striatella a signum is present on corpus bursae ( Volynkin et al. 2019b).

Distribution. Species of the subgenus are known from Nepal and northeastern India through southern continental China, Hainan and Taiwan Islands, Indochina and the Greater Sundas to the Philippines and the island of Sulawesi ( Volynkin et al. 2019b).

Ammatho (Striatella) inexpecta Huang & Volynkin sp. nov.

( Figs 1–4 , 15–17 , 23 )

Miltochrista mesortha Hübner—Fang 2000: 95 , pl. II, fig. 16. [misidentification]

Barsine mesortha (Hübner) —Kishida In: Wang & Kishida 2011: 222, pl. 25, fig. 31; Joshi, Singh & Volynkin 2018 (partim): 463, figs. 18, 40; Volynkin, Černý & Huang 2019a (partim): 78, figs. 274, 300. [misidentification].

Type material. Holotype: male, altitude 998 m, 23–29.VI.2007, Mt. Nanling , Ruyuan County, Yingde City, Guangdong Province, PR China, leg. Min Wang, preparation in glycerol by Huang ( SCAU).

Paratypes: China: 1 male, same locality as holotype, but 11–14. VI .2019, leg. students major in Plant Protection, class of 2021 ( SCAU) ; Vietnam: 1 male, Tam Dao , 900 m, Tonkin, Duport, slide AV5873 Volynkin ( RBINS) ; 1 female, the same locality and collector / 207 / Miltochrista mesortha Hmpsn. , slide AV5874 Volynkin ( RBINS) ; 1 female, Vietnam, Vinh Phuc Province: Tam Dao, roof of Hoang Long Hotel , N21°27.471' E105°38.679', 09.IX. 2014, 952 m . At light. leg. G. Martin, BMNH (E) 2014–174 ( NHMUK); 1 female, North Vietnam, Tam Dao (secondary forest), 60 km NW Hanoi, 1200 m (21.34' N 105.20 'E), 1–5. V .1993, leg. Sinyaev & Simonov, slide MWM 33611 Volynkin ( MWM / ZSM) ; 1 male, Vietnam sept., Tam Dao , 6.IX.–5.X.1977, leg. Kubát, slide AV3379 Volynkin ( CKC) .

Diagnosis. Externally A. inexpecta sp. nov. is very similar to its closest relative A. mesortha ( Hampson, 1898) ( Figs 5–6 , 18 , 24 ) described from Khasi Hills, Northeastern India, but it can be readily distinguished from the latter by its forewing without a black longitudinal stripe in the subbasal area (that is presented in A. mesortha ). In the male genitalia capsule A. inexpecta sp. nov. differs from A. mesortha by its shorter and narrower medial costal process (that is longer and broader in A. mesortha ) and much shorter and tooth-like distal saccular process (that is longer and spine-like in A. mesortha ). In the aedeagus vesica, the new species differs from A. mesortha by its lateral medial diverticulum bilobate distally (that is unilobate in A. mesortha ), and ventral medial diverticulum being much more elongated and covered by smaller cornuti (that is short, robust and covered by slightly larger cornuti in A. mesortha ). In the female genitalia A. inexpecta sp. nov. can be easily distinguished from those of A. mesortha by its M-shaped, broader and laterally expanded posterior end of antrum, anteriorly broader ductus bursae, posterior part of corpus bursae scattered with larger spinules, the presence of a signum in the anterior part of corpus bursae, and longer and broader distal end of appendix bursae, whereas in A. mesortha the posterior end of antrum is V-shaped and narrower, the ductus bursae is narrower anteriorly, the posterior part of corpus bursae is covered with granulation, a signum is absent and the distal end of appendix bursae is shorter and narrower.

Description. Male. Length of forewing is 10.6–11 mm (11 mm in holotype). Antenna long, ciliated, orange in basal two thirds and black in distal one third. Head and thorax covered by reddish scales dorsally, abdomen mostly covered by pinkish white hair. Forewing broad, ground color orange red, pattern black or yellow. Costa is black from base to apex. Subbasal spot small and rounded. Antemedial line breaks near the base of discoidal cell and becomes two separated black dashes. Medial line is broad and straight. Two large ochreous yellow patches present between medial line and postmedial line and are separated by an orange red stroke. Postmedial line broad, protrudes outwards at vein M 3. Several blackish lengthwise strokes present in postmedial zone and connect to postmedial line. These strokes are extending outwards along vein and varying in length. Cilia black. Hindwing ground color pale yellow with a pinkish tint in fresh specimens and the ground color becomes whitish in worn out ones. Medial line blackish and slightly wavy, clearly extending from costa to vein 1A and becomes obscure from vein 1A to dorsum. Postmedial line blackish and vestigial thoroughly, running from costa to CuA 2. A diffuse blackish patch presented around apex. Cilia black from apex to vein CuA 2 and pinkish scattered with black from CuA 2 to tornus.

Male genitalia. Uncus slender, gradually narrowing towards tip. Tegumen triangular. Juxta broad, arrow-like. Saccus broad, U-shaped. Valva relatively broad; costa long and strongly sclerotized; medial costal process broad at base, abruptly narrowing towards tip; distal costal process triangular, varying in length; membranous lobe of valva small; sacculus strongly sclerotized, with its inner edge densely setose basally; distal saccular process short and tooth-like. Aedeagus long and broad; vesica broad, basal diverticulum membranous and broad, conical-shaped or rectangular-like, covered by granulation distally; lateral medial diverticulum directed ventrally and bilobated distally, covered by granulation thoroughly; distal medial diverticulum semi-globular, surface covered by small triangular cornuti; basal ventral diverticulum large and broad; distal ventral diverticulum very long, covered by numerous small triangular cornuti of different sizes and granulation thoroughly.

Female. Length of forewing is 12.5 mm. Size slightly larger than male with forewing broader, and the wing pattern is similar to that of male.

Female genitalia. Papilla analis rectangular; apophysis posterioris and anterioris long and slender, sclerotized, and the former slightly longer than the latter; posterior end of antrum broad, M-shaped; ductus bursae moderately long and broad, sclerotized in the middle; corpus bursae large and globular, posterior section covered by spinules field, medial and anterior section covered by dense granulation; signum presents, rounded; appendix bursae long and strongly sclerotized, with its distal end bending inwards.

Distribution. Currently the new species is known from Nanling Mountains in Guangdong and Hunan Provinces located in Southern China and the Tam Dao mountain range, Vinh Phuc Province in Northern Vietnam. The closely related A. mesortha is distributed in Northeastern India and Northern Myanmar ( Hampson 1898; Joshi et al. 2018).

Etymology. The specific epithet inexpecta means “unexpected” in Latin, referring to the unexpectedness when the authors found it differs from A. mesortha significantly in genitalia structure of both sexes.

Remarks. 1. Fang (2000) recorded and illustrated Miltochrista mesortha (now Ammatho mesortha ) from Mt. Mang, Hunan Province, which is situated within the Nanling mountain range and only about 20 km away from the type locality of A. inexpecta sp. nov. Judging by the figure in Fang (2000), the specimen examined by Fang is undoubtedly conspecific with the new species due to the absence of a black longitudinal stripe in the subbasal area on forewing upperside and definitely not the true mesortha .

2. Volynkin et al. (2019a) erroneously illustrated the female genitalia of A. inexpecta sp. nov. as those of A. mesortha , and here we illustrated the true female genitalia of A. mesortha for the first time.

Figures

FIGURES 1–6. Ammatho (Striatella) spp. adults. 1, A. inexpecta sp. nov., holotype male, S China, Guangdong (SCAU); 2, A. inexpecta sp. nov., paratype male, S China, Guangdong (SCAU); 3, A. inexpecta sp. nov., paratype male, N Vietnam, Tam Dao (RBINS); 4, A. inexpecta sp. nov., paratype female, N Vietnam, Tam Dao (©NHMUK); 5, A. mesortha, syntype male, NE India, Khasis (©NHMUK); 6, A. mesortha, female, NE India, Assam (MWM/ZSM). Scale=1 cm.

FIGURES 15–18. Male genitalia of Ammatho (Striatella) spp. 15, A. inexpecta sp. nov., holotype, preparation Huang; 16, A. inexpecta sp. nov., paratype, preparation Huang; 17, A. inexpecta sp. nov., paratype, slide AV3379; 18, A. mesortha, slide AV1855.

FIGURES 23–27. Female genitalia of Ammatho spp. 23, A. (S.) inexpecta sp. nov., paratype, slide MWM33611; 24, A. (S.) mesortha, slide ZSM Arct.2020-112; 25, A. (A.) shingwa sp. nov., paratype, slide ZSM Arct. 2019-822; 26, A. (A.) garo, paratype, slide MWM31770; 27, A. (A.) midzhan, paratype, slide MWM31768.