A taxonomic study of Gandaritis flavomacularia and related species (Lepidoptera, Geometridae), with description of a new species from western China

333 A taxonomic study of Gandaritis flavomacularia and related species (Lepidoptera, Geometridae), with description of a new species from western China Boxin Wen1,2 , Rui Cheng1 1 State Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, No.1, Beichen West Road, Chaoyang District, Beijing, 100101, China 2 Institute of Xizang Plateau Ecology, Xizang Agricultural & Animal Husbandry University, Linzhi, Xizang, 860000, China Corresponding author: Rui Cheng ([email protected]) Copyright: © Boxin Wen & Rui Cheng. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International – CC BY 4.0). Research Article Abstract The taxonomic status of Gandaritis flavomacularia has recently undergone revision. This study evaluates the validity of G. flavomacularia based on both morphological and molecular evidence. Furthermore, a new, closely related species, Gandaritis stueningi Wen & Cheng, sp. nov. from Sichuan, China, is described, supported by both molecular and morphological data. Key morphological characters, including the male and female genitalia, are illustrated and compared with those of three related species. Key words: COI, DNA barcoding, Larentiinae, morphology, systematics, taxonomy Introduction Gandaritis flavomacularia Leech, 1897 (Larentiinae) was originally described on the basis of two type specimens (a male and a female) from Wa-Shan, Sichuan, western China. Prout (1915) later transferred this species to the genus Lygris Hübner, 1825, citing the ‘absence of secondary sexual characters’. Herbulot (1964) synonymized Lygris with Eulithis Hübner, 1821, resulting in the new combination: Eulithis flavomacularia. This taxonomic treatment was followed by Parsons et al. (1999) and Rajaei et al. (2022). Xue and Zhu (1999) subsequently reassigned flavomacularia to Gandaritis based on a comprehensive suite of characters, including wing venation and genital morphology. Molecular data further support the validity of G. flavomacularia within Gandaritis (Fig. 1). This species has two close relatives: G. tristis (Prout, 1938) and G. flavescens Xue, 1992. Gandaritis tristis is known from the nearby holotype locality (Ta-tsien-lu, Sichuan, China), shares a similar wing pattern and also lacks secondary sexual characters, but exhibits a distinctive yellow costal patch extending to the wing apex. Gandaritis flavescens is known from Sangzhi, Hunan, China, and shares strongly biangulate hindwing discocellulars with G. flavomacularia. Academic editor: Gunnar Brehm Received: 14 July 2025 Accepted: 12 September 2025 Published: 15 October 2025 ZooBank: https://zoobank. org/4B412F00-7259-4A42-AF2CC727AFC0E356 Citation: Wen B, Cheng R (2025) A taxonomic study of Gandaritis flavomacularia and related species (Lepidoptera, Geometridae), with description of a new species from western China. ZooKeys 1255: 333–341. https://doi.org/10.3897/ zookeys.1255.165076 ZooKeys 1255: 333–341 (2025) DOI: 10.3897/zookeys.1255.165076 334 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China Stüning and Fu (2019) affirmed the findings of Xue and Zhu (1999) and provided a comprehensive review of the genus’s taxonomic history, establishing a foundation for further research. Within Gandaritis, the presence or absence of secondary sexual characters and the shape of the hindwing discocellulars exhibit overlapping variation (Xue and Zhu 1999), indicating that reliance solely on the ‘absence of secondary sexual characters’ may be misleading. For instance, both G. tristis and G. fixseni (Bremer, 1864) lack secondary sexual characters, while strongly biangulate hindwing discocellulars—characteristic of G. flavomacularia—also occur in G. tricedista (Prout, 1938), G. flavescens, G. nigroagnes Xue, 1999, and G. agnes (Butler, 1878). Currently, Gandaritis comprises 22 species (Choi 2001; Stüning and Fu 2019; Rajaei et al. 2022), 16 of which occur in China. Typical diagnostic characters of Gandaritis include: the central fascia on the forewing, comprising dots or a band, is strongly projected outwardly on the middle of veins M2 or M3; termen of both foreand hindwings usually shows an orange band with blackish dots; the male genitalia are similar to those of Eulithis, but distinguished by the long anellus lobe that exceeds half the length of the tegumen, the broad apical part of the anellus lobe with long, hair-like setae, the costa of the valva is slightly expanded medially, and the vesica lacks cornuti (Prout 1915; Choi 2001). During further examination of Gandaritis specimens from Institute of Zoology, Chinese Academy of Sciences, Beijing, China (IZCAS) and Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany (ZFMK), we discovered an undescribed species morphologically similar to G. flavomacularia and G. tristis, sympatric with them in western China. Here, we describe this new species, provide comparative illustrations of external and genital morphology for both sexes, and present DNA barcode evidence supporting its distinct status. Figure 1. Neighbour-joining (NJ) tree of selected Gandaritis based on the Kimura two-parameter model. 335 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China Material and methods All studied specimens, including the types of the new species, are deposited in IZCAS or ZFMK. Wing venation terminology follows the Comstock-Needham system (Comstock 1918), as adopted for Geometridae by Scoble (1992) and Hausmann (2001), while genitalia terminology follows Pierce (1914, reprinted 1976), Klots (1970), and Nichols (1989). Moths photographs were taken with a digital camera (Canon Pc1057), 20 cm LED Photography Shadowless Light (Color temperature: 6000–6500 K, 600 lm), and composite images were generated using Auto-Montage software (ver. 5.03.0061, Synoptics Ltd). Plates were compiled in Adobe Photoshop (ver. 2020). A total of six DNA barcodes from IZCAS specimens were included in this study, comprising four sequences of the new species and two sequences of G. flavomacularia. A further eight sequences from four other Gandaritis species were obtained from the BOLD system (https://boldsystems.org/). Details of all specimens are summarized in Appendix 1. DNA extraction and sequencing followed the protocols described by Cheng et al. (2025). Sequences were aligned using MEGA 6.0 (Tamura et al. 2013) and a neighbour-joining (NJ) tree (Saitou and Nei 1987) was constructed based on Kimura two-parameter (K2P) distances (Kimura 1980). Systematics Gandaritis stueningi Wen & Cheng, sp. nov. https://zoobank.org/6DDE2CCF-828F-4A0E-AAA2-AA7FFA2D3DB9 Figs 2–6, 17–20, 25 Chinese common name: 斯氏枯叶尺蛾 Type material. Holotype, ♂, China: Sichuan (IZCAS): • Pingwu, Wanglang, 2446 m, 21–22.VII.2016, leg. Cui Le, slide no. Geom-07564, IOZ LEP M 22602. Paratypes: Shaanxi (IZCAS): • 1 ♂, 1 ♀, Tiantaishan, Jialingjiang, 1062 m, 8–9.VIII.2014, leg. Xue Dayong, slide no. Geom-07566, IOZ LEP M 15798, 15862; • 1 ♀, Ningshan, Huoditang, 1550 m, 8.VII.2008, leg. Cui Junzhi; • 1 ♂, 1 ♀, (IZCAS, ex. ZFMK), Tapaishan im Tsinling Sued-Shensi, ca. 1700 m, 8.VIII.1936, leg. H. Höne, slide no. Geom-01949. Shaanxi (ZFMK), 3 ♀, Tapaishan im Tsinling Sued-Shensi, ca. 1700 m, 22–26.VII.1935, leg. H. Höne; • 4 ♂, 2 ♀, ibidem, 6–19.VIII.1935; • 6 ♂, 8 ♀, ibidem, 5–19.VIII.1936; • 1 ♀, Tapaishan im Tsinling Sued-Shensi, ca. 3000 m, 25.VII.1935, leg. H. Höne; • 3 ♂, 3 ♀, ibidem, 11–25.VIII.1936. Gansu (IZCAS), 8 ♀, Dangchang, Guanegou, 2045 m, 1–3.VIII.2016, leg. Cheng Rui & Jiang Shan; • 1 ♀, Wenxian, Liziba, 1971 m, 22–24.VIII.2014, leg. Li Xinxin; • 2 ♀, Wenxian, Qiujiaba, 2200 m, 16–19.VII.2003, leg. Wang Hongjian; • 1 ♀, Kangxian, Qinghe, 1400 m, 7.VII.1999, leg. Zhu Chaodong. Sichuan (IZCAS), 1 ♀, Pingwu, Wanglang, 2504 m, 23.VII.2016, leg. Cui Le, slide no. Geom-07563, IOZ LEP M 22674; • 10 ♀, Pingwu, Wanglang, 2410 m, 5.VIII.1999, leg. Zhou Xin. Description. Head. Antennae filiform in both sexes, lacking cilia. Head coloration dark grayish-brown to blackish-brown. Labial palpus moderately long, extending beyond frons. Vertex grey-brown, intermixed with grayish-white scales. Thorax. Dorsally dark grayish-brown to blackish-brown. Leg coxae grayish-white, femora to tarsi pale yellowish-gray, intermixed with dark grayish-brown. 336 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China Patagia sparsely mixed with yellowish scales. Forewing length: ♂ 26–27 mm, ♀ 29–31 mm. Wings broad; forewing with apex pointed, slightly protruding; outer margin gently curved. Hindwing termen arched. Discocellular of hind wing strongly Figures 2–16. Wing pattern of Gandaritis species. 2–6 G. stueningi sp. nov. 2. Holotype, male, upperside (in: IZCAS); 3. Ibidem, underside; 4, 5. Paratype, female, upperside (in: IZCAS); 6. Ibidem, underside; 7–10. G. flavomacularia. 7. Male, upperside (in: IZCAS); 8. Ibidem, underside; 9. Female, upperside; 10. Ibidem, underside; 11, 12. G. flavescens. 11. Holotype, male, upperside (in: IZCAS); 12. Ibidem, underside; 13–16. G. tristis. 13. Male, upperside (in: ZFMK); 14. Ibidem, underside; 15. Female, upperside (in: ZFMK); 16. Ibidem, underside. Scale bars: 1 cm. 337 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China Figures 17–26. Male and female genitalia. 17–24. Male genitalia. 17–20. G. stueningi sp. nov.; 17, 18. Holotype (slide no.: 07564); 19, 20. Paratype (slide no.: 01949); 21, 22 G. flavomacularia (slide no.: 07562); 23, 24. G. flavescens (slide no.: 02073); 25–26. Female genitalia. 25. G. stueningi sp. nov., paratype (slide no.: 07563); 26. G. flavomacularia Leech (slide no.: 07561). Scale bars: 0.5 mm. 338 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China biangulate; vein D2 distinctly longer than D1 and D3; base of M2 slightly close to M3. Wing omit comma color brown to blackish-brown. Forewing with white antemedial, medial, and postmedial lines. Antemedial line oblique outward from costa to discal cell, slightly thickened, bending inward within cell, slightly wavy to inner margin. Median line thickened at costa, forming an outwardly oblique wedge-shaped white patch, angled backward within discal cell and slightly wavy to inner margin. Postmedial line narrow white streak, tapering, extending obliquely to mid-vein M2, following part inclined to basal 1/3 of CuA2 or often invisible, then slightly thicken and wavy to inner margin. Submarginal and terminal lines absent. Fringes thickened with wing. Hindwing. Costa grayish-white from base to postmedial line; area below often tinged with yellow, sometimes expanding downward forming diffuse yellow patch at mid-wing. Discal spot round, dark brown, faint. Postmedial line stout, yellow, deeply curved, lower half slightly wavy. Submarginal line curved, composed of a series of crescent-shaped yellow spots. Costa yellow from submarginal line to apex. Fringes yellow at apex, remainder concolorous with wing. Forewing underside. Mostly yellowish; costa to discal cell intermixed with grayish-white and dark brown; distal part blackish. Dark brown patch present at middle of anterior margin of discal cell. Discal spot rounded, dark brown. Postmedial line blackish, anterior part very broad, forming a “>”-shaped angle; posterior part tapering and bent outward near inner margin. Submarginal line blackish, curved, discontinuous on veins, almost merged with blackish distal part near costa. Underside of male forewing without secondary sexual characteristics. Hindwing underside. Grayish-white to pale grayish-yellow, mixed with brown. Postmedial and submarginal lines blackish; the former deeply curved, with posterior part broader; the latter broad and arcuate, interrupted on veins. Discal spot more distinct than upperside. Abdomen. Its dorsal side dark grayish-brown to blackish-brown, intermixed with grayish-white scales; ventral sides grayish-white. Setal patch on male third sternite absent. Male genitalia (Figs 17–20). Uncus very long, narrow, apex pointed. Tegumen simple. Juxta broad, bearing well sclerotized conical process medially on posterior margin. Anellus lobe developed, extremely robust, truncate at apex, densely covered with long hairs, tip swollen. Saccus short and broad. Valva wide and simple. Aedeagus stout, large, its middle part broad; vesica large, membranous, lacking cornuti. Manica with a short, tongue-like process, surrounding membrane finely spined. Female genitalia (Fig. 25). Papilla anales simple. Apophyses posteriores and anteriores slender and elongate. Lamella antevaginalis narrow, semicircular, sclerotized band. Ductus bursae approximately two-thirds length of elliptical corpus bursae; colliculum present at lower half. Corpus bursae bears an irregularly shaped signum, located at middle area and ventral side, composed of numerous spinules. Diagnosis. This species is morphological similar to G. flavomacularia (Figs 7–10). Compared to G. flavomacularia, the wing color of G. stueningi sp. nov. is darker; the white streak along the forewing postmedial line is narrower, straighter, and more steeply inclined. In G. stueningi sp. nov., the submarginal and terminal lines are absent, whereas in G. flavomacularia, the submarginal line consists of a series of white spots of various sizes, and the terminal line forms a series of yellow dots at the end of veins. On the underside, G. stueningi sp. nov. is darker, and the postmedial line is more strongly protruding, forming a “>” shape, while in G. flavomacularia, the postmedial line is less convex, and connected to the submarginal 339 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China line by a black-brown spot. The genitalia also differ: the male saccus in the new species is narrower than that in G. flavomacularia (Figs 21, 22) and in the female of the new species, the antrum is shorter and the signum more slender than in G. flavomacularia (Fig. 26). Unlike G. tristis (Figs 13–16), which has a yellow costal patch extending to the wing apex, G. stueningi sp. nov. shows white spots along the upper half of the postmedial line. Although molecular evidence supports the closest relationship of this new species with G. flavescens (Figs 11, 12), G. stueningi sp. nov. can be distinguished by the absence of secondary sexual characteristics. Distribution. China (Shaanxi, Gansu, Sichuan). Etymology. The species is named after Dr Dieter Stüning (Bonn, Germany), former curator of Lepidoptera at the Zoological Research Museum Alexander Koenig, Bonn, and a well-known specialist, for his significant contributions to Geometridae taxonomy. Molecular data. Gandaritis stueningi is clearly separated from closely related species based on COI barcode sequences (Fig. 1). The genetic distance between G. stueningi and G. flavescens is 2.11% to 2.77%, and between G. stueningi and G. flavomacularia is 5.13% to 5.30%. The mean intraspecific distance of G. stueningi is 0.68% (range 0–1.07%; N = 4). Acknowledgements We sincerely thank Prof. Dayong XUE (IZCAS) for his kind assistance, and Dr Dieter Stüning (ZFMK) for his valuable support, including providing adult images of G. tristis and paratypes information. This work was supported by the Biological Resources Programme, Chinese Academy of Sciences, State Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management (SKLA2501) and National Science Foundation of China (32170464, 32330013). Additional information Conflict of interest The authors have declared that no competing interests exist. Ethical statement No ethical statement was reported. Use of AI No use of AI was reported. Funding This work was supported by Institute of Zoology, Chinese Academy of Sciences. Author contributions Conceptualization: CR. Data curation: CR. Investigation: WBX. Visualization: WBX, CR. Writing - original draft: WBX, CR. Author ORCIDs Boxin Wen https://orcid.org/0009-0008-6405-4733 Rui Cheng https://orcid.org/0000-0002-3044-4724 340 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China Data availability All of the data that support the findings of this study are available in the main text or Supplementary Information. References Cheng R, Jiang N, Luo AR, Zhou QS, Mi XY, Zhu CD, Han HX (2025) Integrative taxonomy of Ourapteryx leach (Geometridae, Lepidoptera) based on molecular and morphological evidences. Journal of Zoological Systematics and Evolutionary Research 2025(1): 5450629. https://doi.org/10.1155/jzs/5450629 Comstock JH (1918) The Wings of Insects. Comstock Publishing Company. Choi SW (2001) Phylogeny of Eulithis Hübner and related genera (Lepidoptera: Geometridae), with an implication of wing pattern evolution. American Museum Novitates 3318: 1–37 [24 figs, 2 tabs]. https://doi.org/10.1206/0003-0082(2001)318%3C0001:- POEHBA%3E2.0.CO;2 Hausmann A (2001) Introduction. Archierarinae, Orthostixinae, Desmobathrinae, Alsophilinae, Geometrinae. The Geometrid moths of Europe (Vol. 1). Apollo Books. Herbulot C (1964) Corrections a ma mise a jour de la liste des Geometridae de France. Alexanor 3: 376–377. Kimura M (1980) A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences. Journal of Molecular Evolution 16(2): 111–120. https://doi.org/10.1007/BF01731581 Klots AB (1970) Lepidoptera. In: Tuxen SL (Ed.) Taxonomist’s glossary of genitalia in insects. Munksgaard. Nichols SW (1989) The Torre-Bueno Glossary of Entomology. New York Entomological Society in cooperation with the American Museum of Natural History. Parsons MS, Scoble MJ, Honey MR, Pitkin LM, Pitkin BR (1999) Geometrid Moths of the World: A Catalogue (Lepidoptera, Geometridae) (Vol. 1). In: Scoble MJ (Ed.) CSIRO Publishing, Collingwood, Victoria and Apollo Books, Stenstrup, 392 pp. https://doi. org/10.1071/9780643101050 Pierce FN (1914) The genitalia of the group Geometridae of the British islands. E.W. Classey Ltd. [reprinted 1967] Prout LB (1915) [1912–1916] The Palaearctic Geometrae. The Macrolepidoptera of the World (Vol 4) In: Seitz A (Ed.) Stuttgart, Verlag A. Kernen, 1–479. Rajaei H, Hausmann A, Scoble M, Wanke D, Plotkin D, Brehm G, Murillo-Ramos L, Sihvonen P (2022) An online taxonomic facility of Geometridae (Lepidoptera), with an overview of global species richness and systematics. Integrative Systematics 5(2): 145–192. https://doi.org/10.18476/2022.577933 Saitou N, Nei M (1987) The neighbor-joining method, a new method for reconstructing phylogenetic trees. Molecular Biology and Evolution 4: 406–425. Scoble MJ (1992) The Lepidoptera, form, function and diversity. Oxford University Press. Stüning D, Fu CM (2019) Notes on Gandaritis Moore, 1868, with description of two new taxa from Taiwan and N. Vietnam (Lepidoptera, Geometridae, Larentiinae). Tinea 25(Suppl. 1): 170–183. Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: Molecular evolutionary genetics analysis version 6.0. Molecular Biology and Evolution 30(12): 2725– 2729. https://doi.org/10.1093/molbev/mst197 Xue DY, Zhu HF (1999) Fauna Sinica, Insecta Vol. 15. Lepidoptera, Geometridae, Larentiinae. Science Press, Beijing, 1090 pp [25 pls]. 341 ZooKeys 1255: 333–341 (2025), DOI: 10.3897/zookeys.1255.165076 Boxin Wen & Rui Cheng: A new species of Gandaritis from China Appendix 1 Table A1. Details of specimens used in the molecular analysis of the DNA barcode region. Sample ID Species Date collected Locality Collectors GenBank /BOLD accession numbers IOZ LEP M 22875 G. flavomacularia 1.VIII.2016 Baoxing, Sichuan, China Cui Le PV918580 IOZ LEP M 22510 G. flavomacularia 15.VII.2016 Jiguanshan, Sichuan, China ditto PV918581 IOZ LEP M 22674 G. stueningi 23.VII.2016 Pingwu, Sichuan, China ditto PV918582 IOZ LEP M 22602 G. stueningi ditto ditto ditto PV918583 IOZ LEP M 15798 G. stueningi 8.VIII.2014 Tiantaishan, Shaanxi, China Xue Dayong PV918584 IOZ LEP M 15862 G. stueningi ditto ditto Ban Xiaoshuang PV918585 KLM Lep 02811 G. pyraliata 22.VI.2014 Kaernten, Austria Wieser Ch. OR369486 TLMF Lep 18953 G. pyraliata 28.VII.2013 Tyrol, Osttirol, Austria Deutsch H. OR369353 LSNOE Lep 00989 G. pyraliata 21.VIII.2010 Niederoeste-rreich, Austria W. Stark OR369308 TLMF Lep 23926 G. pyraliata 14.VI.2017 Burgenland, Austria Huemer P. OR369208 AYK-04-1280-07 G. sinicaria 2.VIII.2004 Taiwan, China Akito Y. Kawahara KF522414 AYK-04-5649 G. fixseni 1.VIII.2008 Shizuoka, Japan ditto KF522413 BC AxYi 0025 G. flavescens 25.VII.2011 Beijing, China Zou Y GWOTL785-13 MF052653 G. flavescens Beijing, China Hao MD GBMNC53060-20 Supplementary material 1 DNA sequence Authors: Boxin Wen, Rui Cheng Data type: txt Copyright notice: This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited. Link: https://doi.org/10.3897/zookeys.1255.165076.suppl1