China: Shaanxi (IZCAS): 1♂, Ningshan, Huoditang, 1497 m, 29–31.VII.2018, leg. Zhang Xinyi; 1♂1♀, Taibai, Huangbaiyuan, 1279 m, 15–17.VII.2018, leg. Zhang Xinyi; 2♂, Foping, Yueba, 1052 m, 1–3.VIII.2018, leg. Zhang Xinyi; 1♀, Ningshan, Guanghuojie, Baohuzhan, 1189 m, 26–28.VII.2014, leg. Liu Shuxian, slide no. Geom-5167; 11♂1♀, Ningshan, Guanghuojie, 1101 m, 27–28.VII.2018, leg. Zhang Xinyi, slide no. Geom-5928 (♂); 13♂3♀, Shangnan, Jinsixia, 766–777 m, 23–25.VII.2013, 16–19.VII.2017, leg. Cui Le, slide no. Geom-5136 (♂), 5137 (♂), 5138 (♀), 5163 (♂), 5164 (♂), 5165 (♂), 5166 (♂), 5168 (♀), 5184 (♂), 5185 (♂). Hubei (IZCAS): 13♂2♀, Shennongjia, Chaoshuihe, 860 m, 21–23.VI.2019, leg. Cheng Rui. Sichuan (IZCAS): 1♂4♀, Emeishan, Qingyinge, 800–1000 m, 19.VI.–15.VII.1957, leg. Zhu Fuxing et al., slide no. Geom-5162 (♀); 5♂, Mianzhu, Jiulongshan, Shizipo, 810 m, 29–31.VII.2016, leg. Cui Le, slide no. Geom-4134 (♂), 5158 (♂), 5186 (♂); 8♂5♀, Baoxing, Fengtongzhai, Dashuigou, 1590 m, 1–5.VIII.2016, leg. Cui Le, slide no. Geom-4135 (♀), 5180 (♂); 3♂1♀, Chongzhou, Jiguanshan, Anzihe, Shaoyaogou, 1556 m, 11–16.VII.2016, leg. Cui Le, slide no. Geom-4141 (♂); 11♂12♀, Mianzhu, Dajianping, 877 m, 17–18.VII.2019, leg. Zhang Xinyi; 6♂7♀, Wenchuan, Huangjiacun, 1033 m, 13–14.VII.2019, leg. Zhang Xinyi; 13♂11♀, Pengzhou, Dingjiawanping, 1088 m, 15–16.VII.2019, leg. Zhang Xinyi; 6♂7♀, Tianquan, Lianglukou, 1405 m, 1–2.VII.2019, leg. Zhang Xinyi.

As Prout (1913, 1938) stated, I. proximaria is similar to I. craspedota (Fig. 14) in the wing pattern, but the latter lacks the areole on the forewing. The genitalia of the two species are quite different: the uncus is truncate with tiny protuberances in I. proximaria, but tapering and pointed in I. craspedota (Fig. 23); the gnathos is developed in I. proximaria, but only bears a blunt median process in I. craspedota; the valva has different decorations in I. proximaria, but is very narrow and simple in I. craspedota; the anellus is very large in I. proximaria but reduced in I. craspedota. In the female genitalia, the ductus bursae of I. proximaria is very broad but quite narrow in I. craspedota (Fig. 34).

Head. Antennae ciliate in male, filiform with sparse cilia in female, cilia shorter in female. Frons dark, with sparsely scattered brown scales, not protruding. Labial palpus dark brown on dorsal side and paler on ventral side, third segment ~ 1/2 length of second segment, extending beyond frons. Vertex pale brown.

Thorax. Tegula pale brown. Hind leg in male modified; hind tibia dilated; first segment of tarsus very broad and flat, shaped like a bird’s wing, covered with darkish scales, the inner side bearing a bunch of long hair-pencils from base of tibia to tip of tarsus, other tarsomeres vestigial. Hind tibia in female normal, with one pair of terminal spurs. Forewing length: male 9–11 mm, female 9–12 mm. Wings pale brown, diffused with dark scales. Forewing with costa straight, distal one-third convex; apex protruding; outer margin slightly convex. Forewing with costa dark purplish brown; antemedial line vague, discernible by a small patch on costal margin; postmedial line sinuous, appearing as black dots on veins, vague between veins; terminal margin a narrow dark purplish brown band; an indistinct darkish patch present at middle of hind margin. Hind wing with outer margin slightly protruding on vein M₃; postmedial line and terminal margin same as on forewing. Both wings with black discal spot. Fringes reddish brown, decorated with dark scales on vein ends. Underside: paler than upperside; forewing with basal part diffused with greyish scales; postmedial line more continuous than on upperside; terminal band much narrower.

Abdomen. Dorsal side pale brown, decorated with dark brown scales, dense on intersegment; ventral side pale brown.

Male genitalia. Uncus spatulate, with two tiny lateral and ventral protuberances at tip. Gnathos developed, tongue-like. Valva long and slender, apex rounded and setose; dorsal margin almost straight to slightly convex, with a subapical mound-like protrusion; ventral margin with a blunt central protrusion. Anellus a very large sclerite, posterior margin smooth and strongly protruding, lateral margin with lower half spinulose. Saccus blunt. Aedeagus short, terminal two-thirds sclerotised and stout, cornutus with one or two spines.

Female genitalia. Ovipositor lobes with small ventral protrusion. Apophyses posteriores ~ 2× length of apophyses anteriores. Region around ostium strongly sclerotised, lamella postvaginalis and antevaginalis irregularly shaped. Ductus bursae very long and broad, wrinkled, with a large scobinate area, anteriorly membranous, the middle part decorated with long spines, posteriorly, with a well sclerotised pouch-like process; an elongate diverticulum present, diverging posteriorly. Corpus bursae small, with a rounded spinose patch.

China (Shaanxi, Hubei, Sichuan).

It has not been possible to examine the genitalia of the syntypes of I. proximaria since neither of them has been dissected. However, since the syntypes and the complete series in the NHMUK (the Natural History Museum, London, United Kingdom) are from Sichuan and we have only seen one species in the complex from Sichuan province, it is reasonable to assume that this is the species described by Leech.

Figures 1–15. 

(1–2) Male hind tibia and tarsus of Idaea proximaria 1 lateral view 2 medial view. (3–14) Adults of Idaea proximaria complex 3–7 I. proximaria 3 male, Jiguanshan, Sichuan 4 female, Baoxing, Sichuan 5–7 Jinsixia, Shaanxi 5–6 male 7 female 8–9 I. rectangularis sp. nov. 8 holotype, male, IZCAS 9 paratype, female, IZCAS 10 I. rectispina sp. nov., holotype, male, IZCAS 11–12 I. setosa sp. nov. 11 holotype, male, IZCAS 12 paratype, female, IZCAS 13 I. linearis sp. nov., holotype, female, IZCAS 14 I. craspedota. 15 Neighbour-Joining (NJ) tree of selected proximaria complex based on the Kimura two-parameter model. Scale bar: 1 cm (3–14).

Figures 16–27. 

(16–23) Male genitalia of Idaea proximaria complex 16–19 I. proximaria 16–17 Shizipo, Sichuan 18–19 Jinsixia, Shaanxi 20 I. rectangularis sp. nov., holotype 21 I. rectispina sp. nov., holotype 22 I. setosa sp. nov., holotype 23 I. craspedota. (24–27) Aedeagus of I. proximaria complex 24–26 I. proximaria 24 Dashuigou, Sichuan 25 Shizipo, Sichuan 26 Jinsixia, Shaanxi 27 I. rectangularis sp. nov., holotype. Scale bars: 1 mm.

In I. proximaria, the aedeagus has a varying number of cornuti on the vesica. For example, some only have one large bent spine (Fig. 24); some have two spines of equal length (Fig. 25), or of different sizes (Fig. 26). The conditions of one spine and two equally sized spines occur among the specimens collected from Shizipo, Sichuan province, and that of two spines of different sizes occur among specimens collected from Jinsixia, Shaanxi province. Other differences could not be found in the armament of the male genitalia (Figs 16–19) or in the female genitalia and wings (Figs 3–7). To determine whether these differences are of intraspecific variations or different species, four fresh specimens from Jinsixia, Shaanxi province were used to obtain barcoding sequences; of these specimens, LEP M 31611 and 31619 bear two equal-sized spines, LEP M 31612 bears two differently sized spines, and LEP M 31623 is a female. The result (Fig. 15) shows that no genetic distance can be found between the four specimens; thus, these specimens are considered to belong to the same species. The genetic distance between I. proximaria and I. craspedota is 8.36% (Fig. 15).

Most public Idaea sequences on BOLD were downloaded, including 32 sequences from China, and a NJ tree was constructed (Suppl. material 1). In the NJ tree, I. proximaria is clustered with two unnamed specimens with very low support values, which means this relationship is unreliable. Through calculating pairwise distances, I. politaria (Hübner) of inquinata species group was found as the nearest related species with a genetic distance 6.15%; however, it is very far from I. proximaria on the NJ tree. It can be inferred that, on the basis of the public COI sequences available on BOLD, the closest species to I. proximaria has not yet been found.

In the present work, the main purpose of DNA barcoding is to identify whether I. proximaria has intraspecific variation; the results of NJ tree for a large number of species are not included, which is beyond the scope of this work, and only three sequences of I. craspedota, with similar wing patterns, are included (Fig. 15).

Holotype , ♂, China: Guangxi (IZCAS): Jinxiu, Linhaishanzhuang, 1000 m, 2.VII.2000, leg. Li Wenzhu, slide no. Geom-5160. Paratypes: Guangxi (IZCAS): 1♂2♀, same data as holotype, slide no. Geom-5161(♀); 1♀, Huanjiang, Yangmeiao, 1189 m, 18–22.VII.2015, leg. Jiang Nan, slide no. Geom-5187. Fujian (IZCAS): 1♀, Chongan, Xingcun, Guadun, 900–1160 m, 8.VII.1963, leg. Zhang Youwei; 1♀, Wuyishan, Dazhulan, 1150 m, 28.VII.2006, leg. Xue Dayong, slide no. Geom-5182.

Compared to I. proximaria, the forewing apex of I. rectangularis is somewhat sharper, and the first segment of male hind tarsus is darker. The male genitalia of I. rectangularis are similar to those of I. proximaria, but can be differentiated by the following characters: the anellus is smaller than that of I. proximaria, and the anterior half lacks spines on the lateral margin in I. rectangularis whereas these are present in I. proximaria; the valva possesses a small blunt finger-like process in I. rectangularis, whereas in I. proximaria there is only a protrusion which does not form a process ; the slightly concave uncus is also different. The aedeagus is distinguished by the number of the cornuti, which is five in I. rectangularis, including one right-angled spine, but only one or two in I. proximaria. In the female genitalia, the region surrounding the ostium is not totally sclerotised, with a separate lamella postvaginalis. The ductus bursae lacks a bag-like process in I. rectangularis but it is present in I. proximaria.

Head. Antennae ciliate in male, filiform in female. Frons, labial palpus, vertex identical to I. proximaria.

Thorax. Hind leg similar to that of I. proximaria, but first segment of male hind tarsus blackish grey. Forewing length: male 10 mm, female 10–11 mm. Wing pattern and markings similar to those of I. proximaria, except that the apex of the male forewing protrudes further.

Abdomen. Male genitalia. Uncus spatulate, posterior margin slightly concave. Gnathos developed, tapering. Valva long and slender, with a sclerotised ridge at middle; apex rounded and setose; dorsal margin slightly concave at middle, with a faint subapical protuberance; ventral margin deeply concave near middle, with a small finger-like blunt process. Saccus blunt. Anellus a large sclerite, posterior half rounded, anterior half an inverted trapezoid. Aedeagus stout, terminal two-thirds sclerotised and broadened; cornutus with five spines, one larger than the rest and right-angled; vesica with a scobinate area.

Female genitalia. Ovipositor lobes with a small ventral protrusion. Apophyses posteriores ~ 2× length of apophyses anteriores. Lamella postvaginalis a laterally elongate sclerite, wrinkled. Lamella antevaginalis shapeless, but with left side of ostium strongly sclerotised, scobinate anteriorly. Ductus bursae very broad, wrinkled, the large posterior half decorated with long spines, anteriorly slightly sclerotised; an elongate posteriorly diverging appendix bursae present. Corpus bursae small, rounded, decorated with an oval spinose patch.

China (Guangxi, Fujian).

This species is named from Latin word rectangularis, which refers to the one right-angled cornutus.

Holotype , ♂, China: Hunan (IZCAS): Yanling, Taoyuandong, 631 m, 4–8.VII.2008, leg. Chen Fuqiang, slide no. Geom-5159.

In the male genitalia, I. rectispina is similar to I. rectangularis in having a concave uncus, tongue-like gnathos, and in the presence of a small finger-like process on the ventral margin of the valva. However, small but differently sized protrusions are present on the valval costal margin of I. rectispina, but absent in I. rectangularis. The number of cornuti in the aedeagus is six and all are straight in I. rectispina, as opposed to the five in I. rectangularis with one right-angled.

Wing pattern almost identical to that of I. proximaria, I. rectangularis, and I. setosa. First segment of male hind tarsus covered with blackish scales. Forewing length: male 10 mm.

Abdomen. Male genitalia. Uncus spatulate, posterior margin slightly concave. Gnathos developed, tongue-like, with tip narrow. Valva long and slender, apex rounded and setose; dorsal margin with basal half decorated with small protrusions of different sizes, asymmetrical on the left and right valvae; ventral margin concave at middle, with a small blunt finger-like process. Saccus narrow and blunt. Anellus a large sclerite. Aedeagus with terminal part broadened, cornutus with six straight spines, vesica also with a scobinate area.

Female genitalia. Unknown.

China (Hunan).

This species is named from Latin prefix rect- and Latin word spina, referring to the straight spines of the cornutus.

Holotype , ♂, China: Hainan (IZCAS): Qiongzhong, Limushan, Qijiacun, 657 m, 6–7.IV.2010, leg. Jiang Nan, slide no. Geom-5140. Paratypes: Hainan (IZCAS): 1♂1♀, Jianfengling, 900 m, 12.IV.1980, leg. Zhang Baolin; 1♂, Baisha, Yinggeling, Nankai, Mohaocun, 336 m, 15–16.IV.2010, leg. Jiang Nan; 1♂1♀, Bawangling, Dongerlinchang, 1015 m, 8–10.V.2007, leg. Chen Fuqiang, slide no. Geom-5141(♀).

The wing pattern is almost identical to that of I. proximaria, I. rectangularis, and I. rectispina. The first segment of the male hind tarsus is pure brown, which is different from the blackish hind tarsus in other species. In the male genitalia, I. setosa is distinctive in the proximaria complex by the uncus having a swollen posterior half, by the triangular gnathos, and by the valva having a subapical ventral spine. The aedeagus is even in width, not broadened posteriorly, and the cornutus has many more spines than in the other species. The female genitalia are distinctive with a very short ductus bursae and the large corpus bursae.

Forewing length: male 10 mm, female 9–12 mm. First segment of male hind tarsus pure brown. Head and wing pattern almost identical to I. proximaria, I. rectangularis, and I. rectispina. Forewing costa lacking dark purplish brown scales in females.

Abdomen. Male genitalia. Uncus long, with posterior half swollen and rounded. Gnathos nearly triangular, with blunt tip. Valva long and slender, tapering, apex rounded and setose; dorsal margin nearly straight and only slightly convex near tip; ventral margin with basal two-thirds straight, concave near apex, bearing a finger-like blunt process. Saccus blunt. Anellus a large sclerite, posterior margin flat, slightly tapering towards anterior margin. Aedeagus in even width, cornutus a bunch of long spines, more than 30 spines.

Female genitalia. Ovipositor lobes with small ventral protrusion. Apophyses posteriores ~ 2× length of apophyses anteriores. Region around ostium membranous, lamella postvaginalis and antevaginalis unmodified. Ductus bursae very short, a small pouch-like process present, an elongate diverticulum present. Corpus bursae very large and rounded, a rounded sclerotised patch present at middle of posterior half, bearing needle-like spines.

Figures 28–34. 

(28–29) Aedeagus of I. proximaria complex 28 I. rectispina sp. nov., holotype 29 I. setosa sp. nov., holotype (30–34) Female genitalia of I. proximaria complex 30 I. proximaria 31 I. rectangularis sp. nov., paratype 32 I. setosa sp. nov., paratype 33 I. linearis sp. nov., holotype 34 I. craspedota. Scale bars: 1 mm.

China (Hainan).

This species is named from Latin word setosus, referring to the bunch of long spines in the cornutus.

Holotype , ♀, China: Hubei (IZCAS): Yingshan, Taohuachong, 590 m, 23–27.VI.2014, leg. Xue Dayong, slide no. Geom-5170. Paratypes: Hubei (IZCAS), 5♀, same data as holotype, leg. Jiang Nan et al., slide no. Geom-5169. Shaanxi (IZCAS): 1♀, Zhashui, Yingpanzhen, Niubeiliang, Laolin, 1046 m, 12–15.VII.2017, leg. Cui Le; 1♀, Foping, Yueba, 1093 m, 29.VI.–1.VII.2012, leg. Li Jing, slide no. Geom-5183; 1♀, Shangnan, Jinsixia, 766 m, 16–19.VII.2017, leg. Cui Le, slide no. Geom-5139.

On the wing pattern, I. linearis is distinctive in that the postmedial line is continuous and does not form black dots on the veins. The female genitalia are distinguished by the smooth lamella postvaginalis, which is divided posteriorly and bears a pair of processes; by the connection of the spinules of the ductus bursae and the corpus bursae, which form a spoon-shaped patch; and by the presence of the appendix bursae diverging anteriorly from the corpus bursae.

Head and wing patterns almost identical to previous species, except that the postmedial line is continuous rather than consisting of black spots on veins. Forewing length: female 10–11 mm. Forewing costa lacking dark purplish brown scales in female, unknown in male.

Abdomen. Male genitalia. Unknown.

Female genitalia. Ovipositor lobes with small ventral protrusion. Apophyses posteriores ~ 2× length of apophyses anteriores. Lamella postvaginalis an elongate smooth sclerite, posterior margin divided, with a pair of proximal processes. Lamella antevaginalis shapeless. Ductus bursae short, wrinkled and spinulose, with a small, rounded, appendix bursae. Corpus bursae nearly oval, lateral half spinulose and joined with spinules of ductus bursae, expanded into centre of corpus bursae, spoon-shaped; with a long, elongate anterior appendix bursae. Seventh sternite with a pair of small proximal bag-like protrusions.

China (Shaanxi, Hubei).

This species is named from the Latin word linearis, referring to the linear postmedial line.