Zootaxa 3682 (1): 178–190 ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2013 Magnolia Press ISSN 1175-5334 (online edition) http://dx.doi.org/10.11646/zootaxa.3682.1.9 http://zoobank.org/urn:lsid:zoobank.org:pub:F6F98526-64C3-4D68-8852-8F6DD9407A1B Morphological variability and taxonomy of Coraebus hastanus Gory & Laporte de Castelnau, 1839 (Coleoptera: Buprestidae: Agrilinae: Coraebini: Coraebina) HONGXIA XU1, 2, VÍTĚZSLAV KUBÁŇ3, MARK G. VOLKOVITSH4, SIQIN GE1, MING BAI1 & XINGKE YANG1,5 1Institute of Zoology, Chinese Academy of Sciences, Beijing, China 2University of Chinese Academy of Sciences, Beijing, China 3National Museum (Natural History), Prague, Czech Republic 4Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia 5Corresponding author. Xingke Yang, Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing 100101, China. E-mail: [email protected] Abstract Coraebus hastanus Gory & Laporte de Castelnau, 1839 is easily distinguished from the other species of the genus Corae- bus Gory & Laporte de Castelnau, 1839. It was divided into three subspecies, but the main diagnostic characters were vari- able. In order to understand the morphological variability and taxonomy of subspecies of C. hastanus, shape of elytral apex, lateral margin of elytra and the aedeagi were analyzed using geometric morphometric and traditional morphometric approaches. Based on the results and distribution patterns of the three subspecies, C. hastanus oberthueri Lewis, 1896 is treated as synonym of C. hastanus Gory & Laporte de Castelnau, 1839, and C. hastanus ephippiatus Théry, 1938 is ele- vated to species rank, and these two species are also redescribed and illustrated. Key words: Coleoptera, Buprestidae, Agrilinae, Coraebini, Coraebina, Coraebus hastanus, Coraebus oberthueri, Corae- bus ephippiatus, taxonomy, morphological variability, Oriental region Introduction Morphological variability is very common in the species of the genus of Coraebus Gory & Laporte de Castelnau, 1839. Many morphological characters were used to distinguish species of Coraebus, the body shape, shape of the elytral apex, coloration and the shape of ornamentation of the dorsal surface (Kubáň, 1996), these characters are usually relatively invariable, but in some closely related species they exhibit a high degree of variability (Kubáň, 1995), which makes it difficult to use them for species differentiation. Coraebus hastanus Gory & Laporte de Castelnau, 1839 is distinctly different from the other species of the genus of Coraebus and it can be easily recognized by the body shape and ornamentation (Descarpentries & Villiers, 1967). Théry (1938) divided C. hastanus into three subspecies: Coraebus hastanus hastanus Gory & Laporte de Castelnau, 1839, C. hastanus oberthueri Lewis, 1896 and C. hastanus ephippiatus Théry, 1938, based on the shape of the elytral apex and lateral margins of elytra. Kurosawa (1953) carefully examined many specimens from the Ryukyu Islands and Taiwan, noticing that among specimens from various of the Ryukyu Islands, only one specimen was closely similar in the shape of elytral apex to C. hastanus oberthueri, other specimens, differed from C. hastanus hastanus in having denticles on the sutural side of inner spine and external side of outer spines. He believed that they were morphological variability of C. hastanus oberthueri. Subsequently, the taxonomic ranks of the three subspecies of C. hastanus were generally accepted by buprestid research community. However, if C. hastanus is indeed represented by three distinct subspecies based on the shape of the elytral apex and lateral margins, the questions of how to identify the subspecies correctly and how to understand their morphological variability remained. Shape analysis is one approach to understanding morphological variability. Traditionally, morphometric data 178 Accepted by Brian Levey: 10 May 2013; published: 26 Jun. 2013 have been measurements of length and width. Such a data set contains relatively little information about shape, and some of this information is fairly ambiguous (Zelditch et al, 2004). Geometric morphometric analyze the shape and morphological structure based on landmarks. With this method, the morphology of an object is represented by the coordinates of a set of landmark points (Bookstein, 1991). It has a tremendous advantage in offering precise and accurate description, allowing us to visualize differences among complex shapes (Fontoura & Morais, 2011). In order to evaluate the morphological variabolity and understand the taxonomy of three subspecies of C. hastanus, we examined the specimens deposited in a number of museums. Morphological variability of aedeagi, apex and lateral margins of elytra were compared by the geometric morphometric approach. Also, the shape of the elytra was compared by the traditional morphometric approach. Based on the results of the morphometric approaches and distributions, C. hastanus oberthueri is treated as a synonym of C. hastanus; and C. hastanus ephippiatus is elevated to species level. Many species of Coraebus and various Coraebini Bedel, 1921 show high morphological variability that makes many traditionally used characters unreliable, we hope that the morphometric approaches used here can provide new ways for analyzing this morphological variability. Material and methods Abbreviations of the collections BMNH The Natural History Museum (British Museum of Natural History), London, Great Britain HBUM Museum of Hebei Univerity, Baoding, Hebei, China IZAS Institute of Zoology, Chinese Academy of Sciences, Beijing, China JSNC Jiangxi Forest Pest and Disease Control Station, Nanchang, Jiangxi, China MNHN Museum national d’Histoire Naturelle, Paris, France NMPC National Museum (Natural History), Prague, Czech Republic USNM United States National Museum of Natural History, Smithsonian Institution, Washington, D.C., U.S.A. VKCB V. Kubáň collection, Brno, Czech Republic ZIN Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia Dissection and imaging. Entire abdomens were separated from the body and kept in distilled water at room temperature for more than 12 hours. The aedeagi or ovipositors were separated from abdominal segments and mounted in a cavity slide under distilled water for observation, photographed in glycerol, then rinsed in water, mounted on a paper card in euparal which was pinned below the specimens. All images were taken using a Nikon D300s digital camera fitted to Zeiss Discovery V12 stereoscopic dissecting microscope. Morphometrics. Landmarks and curves were selected based on homologous or corresponding criteria. Among these, 4 landmarks and 1 curve (30 semi landmarks) designed for elytral apex (Fig. 2A), 3 landmarks and 3 curves (50 semi landmarks) for aedeagi (Fig. 4A) and 2 landmarks, 1 curve (42 semi landmarks) for lateral margin of elytra (Fig. 5A). The images of adeagus (17 specimens), elytral apex (48 specimens) and lateral margin (49 specimens) were entered in tps-UTILS 1.38 (Rohlf, 2006a) and Cartesian coordinates of landmarks were digitized with tps-DIG 2.05 (Rohlf, 2006b). Landmark configurations were scaled, translated and rotated against the consensus configuration using the GLS (Generalized least squares) Procrustes superimposition method (Bookstein, 1991). The coordinates were analyzed using tps-RELW 1.44 (Rohlf, 2006c) to calculate eigenvalues for each principal warp (Bai et al, 2010, 2011, 2012). The parameters of length, width etc of elytra (Fig. 1) from 51 specimens were used to compare morphological variability of elytra; ratio of the different parameters were also calculated except for the elytral length, all the data were obtained from the images taken by the same camera and analyzed by Microsoft Excel (2003) and SPSS (17.0) (Dytham, 2011). Significant difference was analyzed through one way ANOVA and multiple comparisons were conducted by LSD (Least Significant Difference). Measurements. Diagrammatic sketch as in Fig. 1; el—elytra length—from humeri to apex of elytral suture; sl—suture length—from the apex of scutellum to the apex of elytral suture; wa—width of elytral apex—width MORPHOLOGICAL VARIABILITY OF CORAEBUS HASTANUS Zootaxa 3682 (1) © 2013 Magnolia Press · 179 across the bottom of the apical emargination; wb—width of elytral base—elytral width across the apex of scutellum; wm—maximal width of elytra—width across the widest parts of elytra. FIGURE 1. The Diagrammatic sketch of elytral measurements. Results 1. The shape of elytral apex Théry (1938) illustrated the elytral apex of the three subspecies of C. hastanus which were diagnosed mainly by the shape of apex and lateral margin of elytra, however the shape of the elytral apex varies highly. This character varies not only among the different subspecies, but also within same subspecies (Fig. 2). Coraebus hastanus hastanus: elytral apex relatively uniform, no denticles on external side of the outer spine and sutural side of inner spine (Figs. 2A–C); C. hastanus oberthueri: external side of outer spine and sutural side of inner spine with denticles, number of denticles from 1-2 denticles (Fig. 2F) to regular dentation (Figs. 2D–E), sometimes sutural side slightly extended to the outside, even reaching middle of the apex (Fig. 2D, type specimen of C. hastanus oberthueri). We even found a single specimen, having a different shape of elytral apex on each elytron (a specimen from Japan, Okinawa),