Ditrigona fusca Guo & Han, 2022

Guo, Xiao-Jiang, Cheng, Rui, Jiang, Shan, Xue, Da-Yong & Han, Hong-Xiang, 2022, Four new species of Ditrigona Moore (Lepidoptera, Drepanidae) in China and an annotated catalogue, ZooKeys 1091, pp. 57-98 : 57

33. Ditrigona fusca Guo & Han sp. nov.

Figs 35-36 , 74 , 108 , 141 , 170

Description.

Head. Antennae simple in both male and female. Frons yellow, width less than diameter of compound eyes. Labial palpus with outside deep brown, inner side yellowish. Vertex pale yellow.

Thorax. Tegula pale brown. Dorsal and ventral sides of thorax pale brown. Hind tibia with two pairs of spurs in both sexes. Forewing length: ♂16 mm, ♀15-17 mm. Both wings pale brown, evenly decorated with brown scales, less in basal half of hind wing. Transverse lines absent. Fringes yellowish brown. Underside with forewing deep brown, distal part paler, costa yellowish brown; hind wing with costa yellowish brown, other parts identical to upperside. Fringes yellowish brown.

Abdomen. Dorsal and ventral sides of abdomen pale brown. The eighth tergite with posterior margin concave, with two blunt lateral protrusions; the eighth sternite with posterior margin slightly convex, with two small hooked lateral processes.

Male genitalia. Uncus bifurcate over whole length, the arms narrow and slender. Socii large, tongue-like, of even width, with tips blunt and scobinate. Valva nearly triangular, with tip blunt, ventral margin decorated with tiny spines; basal posterior process bent, tip expanded, with a small accompanying bursa. Juxta rounded, with posterior margin protruding, mound-like. Saccus narrow. Aedeagus slender, almost even in width, tip blunt.

Female genitalia. Ostial pocket band-like. Lamella antevaginalis paired leaf-like. Ductus bursae indiscernible. Corpus bursae rounded; signum a narrow longitudinal sclerotized strip; accessory sac absent.

Diagnosis.

The wing pattern is distinctive in lacking transverse lines on both fore- and hind wings. The male genitalia are very close to those of D. candida , D. chionea and D. margarita in the mytylata species group, in that they share the slender bifid uncus and tongue-like socii. D. fusca and D. chionea can be differentiated from those two species by the broader valva, on the base of which a sclerotized ridge is present. The difference between D. fusca and D. chionea in the male genitalia lies in the shape of the juxta, which is widely protruding posteriorly in D. fusca , but only with a tiny process at middle in D. chionea . The aedeagus is also different, straight and almost even in width in D. fusca , but tapering and twisted in D. chionea . The female genitalia of D. fusca and D. chionea are almost identical.

Type material.

Holotype, ♂ (IZCAS), China: Yunnan: Lijiang, Yulong Shan, 23.VIII.1962, leg. Song Shimei, slide no. Drep-1092. Paratypes (IZCAS): Yunnan: same locality and collector as holotype, 1♂, 3.VIII.1962, slide no. Drep-954; 1♀, 30.VII.1962; 2♀, 2.VIII.1962; 1♀, 3.VIII.1962, 2900 m; 3♀, 4.VIII.1962, slide no. Drep-953; 1♀, 23.VIII.1962; 1♀, 25.VIII.1962; 4♀, 30.VIII.1962; 1♀, Xianggelila, Xiaozhongdian, 3235 m, 15-16.VIII.2016, leg. Ban Xiaoshuang, slide no. Drep-1093; 1♀, Lijiang, Alpine Botanical Garden, 3260-3452 m, 16-18.VI.2009, leg. Qi Feng.

Distribution.

China (Yunnan).

Etymology.

The specific name is from the Latin word fuscus, which refers to the pale brown wing colour.

Figures

Figures 28 - 47. Adults of Ditrigona 28 D. lineata lineata, male 29 D. lineata tephroides, holotype, male, ZFMK 30 D. legnichrysa, paratype, male, ZFMK 31 D. policharia, lectotype, female, ZFMK 32 D. artema, male 33 D. candida, paratype, male, ZFMK 34 D. chionea, paratype, male, ZFMK 35, 36 D. fusca sp. nov., holotype, male 35 upperside 36 underside 37 - 38 D. conflexaria micronioides 37 male 38 female 39 D. conflexaria cerodeta, holotype, male, ZFMK 40 D. margarita, male 41 D. berres, male 42 D. chama, male 43 D. platytes, male 44 D. clavata, male 45 D. marmorea, paratype, female ZFMK 46 D. aphya, male 47 D. cirruncata, male. Scale bar: 1 cm.

Figures 64 - 74. Male genitalia of Ditrigona 64 D. sinespina sp. nov., holotype 65 D. parva sp. nov., holotype 66 D. concava sp. nov., paratype 67 D. titana, ZFMK 68 D. pomenaria 69 D. typhodes 70 D. lineata lineata 71 D. artema 72 D. candida, paratype, ZFMK 73 D. chionea 74 D. fusca sp. nov., holotype. Scale bars: 1 mm.

Figures 107 - 127. (107 - 115) Aedeagus of Ditrigona 107 D. chionea 108 D. fusca sp. nov., holotype 109 D. conflexaria micronioides 110 D. margarita 111 D. berres 112 D. chama 113 D. platytes 114 D. clavata 115 D. cirruncata. Scale bars: 1 mm. (116 - 127) Eighth segment of Ditrigona 116 D. derocina 117 D. diana 118 D. crystalla, holotype 119 D. spilota, ZFMK 120 D. furvicosta 121 D. jardanaria 122 D. media 123 D. sericea 124 D. quinaria erminea, ZFMK 125 D. quinaria spodia 126 D. obliquilinea thibetaria 127 D. triangularia

Figures 128 - 151. Eighth segment of Ditrigona 128 D. uniuncusa 129 D. tenuiata, holotype 130 D. regularis 131 D. sinespina sp. nov., holotype 132 D. parva sp. nov., holotype 133 D. concava, paratype 134 D. titana, ZFMK 135 D. pomenaria 136 D. typhodes 137 D. lineata lineata 138 D. artema 139 D. candida, ZFMK 140 D. chionea 141 D. fusca, sp. nov., holotype 142 D. conflexaria micronioides 143 D. margarita 144 D. berres 145 D. chama 146 D. platytes 147 D. clavata 148 - 151 D. cirruncata 148 from Shaanxi 149 - 150 from Emei Shan, Sichuan 151 from Zhejiang.

Figures 161 - 172. Female genitalia of Ditrigona 161 D. tenuiata, paratype 162 D. regularis 163 D. sinespina sp. nov., paratype 164 D. parva sp. nov., paratype 165 D. typhodes 166 D. lineata lineata 167 D. artema 168 D. candida, paratype, ZFMK 169 D. chionea 170 D. fusca sp. nov., paratype 171 D. conflexaria micronioides 172 D. margarita. Scale bars: 1 mm.