A new species of leafhopper, Arboridia sinensis sp. nov., belonging to the subgenus Arboridia Zachvatkin, 1946 s. str. and closely related to Arboridia (Arboridia) gaurii Thapa, 1989, A. cerna Dworakowska, 1977, and A. soror Dworakowska, 1977, is described from Yunnan, China. It differs from A. gaurii in the body coloration and aedeagus shape, and from A. cerna and A. soror also in the shape of its pygofer process. In Yunnan, China the new species lives on Zanthoxylum bungeanum Maximowicz (Rutaceae).
Arboridia Zachvatkin, 1946 is a genus of typhlocybine leafhoppers restricted to the Old World with some 60 species occurring in the Palaearctic and Oriental Regions (Dietrich & Dmitriev 2006; Dmitriev & Dietrich 2003–2009). Currently, Arboridia includes 2 subgenera, Arboridia and Arborifera Sohi & Sandhu, 1971, which differ from each other in the morphology of the genital plates, styles and aedeagus. The genus in its current definition may, however, be polyphyletic (Dietrich & Dmitriev 2006).
In China 2 species of Arboridia have been recorded: Arboridia (Arboridia) apicalis (Nawa, 1913) and Arboridia (Arborifera) surstyli Cai & Xu, 2006. Arboridia apicalis is polyphagous on various deciduous trees and vines: Acer sp. (Sapindales: Sapindaceae), Morus sp. (Rosales: Moraceae), Malus sp., Prunus (Cerasus) sp., Prunus persica (L.) Batsch, Prunus sp., Pyrus communis L. (all Rosales: Rosaceae), Vitis amurensis Ruprecht, V. coignetiae Pulliat ex Planch., and Vitis sp. (all Vitales: Vitaceae), and is distributed in China (NE, Taiwan), far eastern Russia, Japan and the Korean Peninsula. Arboridia surstyli feeds on Macrocarpium officinalis (Sieb, et Zucc.) Nakai (Cornales: Cornaceae) and has been recorded only from China.
In 2011, we examined some specimens of Typhlocybinae from Yunnan Province, China, living on Zanthoxylum bungeanum Maximowicz (Sapindales: Rutaceae), a condiment and medicinal plant known as Chinese prickly-ash and Sichuan pepper tree. On the basis of their external appearance and the morphology of the male genitalia, we describe them as a new species of Arboridia (Arboridia).
MATERIAL AND METHODS
The specimens were collected with entomological nets and aspirators, and preserved in 70% ethanol.
All material studied in this paper is deposited in the following collections: SCAU: The Hymenoptera Collection of South China Agricultural University, Department of Entomology, Guangzhou, Guangdong, P.R. China, GC: Department of Agriculture, Forests, Nature and Energy, University of Tuscia, Viterbo, Italy (Guglielmino's collection), and SMT: Senckenberg Naturhistorische Sammlungen Dresden, Museum für Tierkunde, Germany.
Arboridia (Arboridia) sinensis Guglielmino, Xu, B¨ckle and Dong, sp. nov.
Arboridia (Arboridia) sinensis sp. nov. is probably closely related to A. cerna Dworakowska, A. gaurii Thapa and A. soror Dworakowska for the bifurcate and apically not widened genital styles. In addition, those species show, except for A. soror, a particularly elongate pygofer appendage, the distal part of which is almost straight and directed caudad in A. cerna, whereas it is coiled over its whole length in A. gaurii and A. sinensis. A. sinensis shares with A. gaurii most characters of its genital apparatus, but is distinguished by its different aedeagus shape, which presents a more elongate shaft and a smaller ventral spur, and by its yellow or light greyish brown coloration.
Body length: Males: 3.30–3.80 mm (Holotype 3.45 mm); females: 3.40–3.85 mm. Body yellow or light greyish-brown. Vertex (Fig. 4C in Supplementary Material) yellow or light greyish-brown with 2 broad dark brown bands of irregular shape and unsharply delimited outline, anteriorly diverging and posteriorly fused in a black triangular spot touching hind margin of vertex. Face yellow or light greyish-brown. Pronotum (Figs. 4B, C, E in Supplementary Material) yellow or light greyish-brown. Scutellum (Figs. 4A–E in Supplementary Material) yellow or light greyish-brown with a black, tongue shaped spot on each side. Ventrally, prothorax dark brown, meso- and metathorax yellow or light greyish-brown. Legs yellow or light greyish-brown. Forewing light yellow or greyish-yellow, infumated in basal (in particular on clavus) and apical parts, hyaline in middle area (Figs. 4B–E in Supplementary Material). Hindwing membrane fuliginous, veins uniformly brown. Abdominal segments dark brown.
Male genitalia: Pygofer as in Fig. 1A, with very long, strongly curved and apically narrowing process (Figs. 1A, B) and with robust elongate irregularly shaped sclerite extending between basis of pygofer process and dorsal apodeme of aedeagus (Fig. 1A). Anal tube with slightly sclerotised anteriorly directed lateral process on each side (Fig. 1A). Genital plates slightly exceeding pygofer, distally curved and twisted laterad, with laterally 4 or 5 long macrosetae and numerous irregularly arranged stout, short and black setae on inner part of folded dorsal side (Figs. 1A, C). Genital styles bifurcate and apically not widened with lateral branch shorter and thinner than caudal branch (Figs. 1E, F). Connective with geniculate branches, stem short (Fig. 1D). Aedeagus (Figs. 2A, B) laterally compressed, shaft apically with 3 lamellae: one sagittal lamella and 2 lamellae in dorsolateral direction originating on each side from dorsal margin of sagittal lamella. Ventral surface of shaft with preapical gonopore and small spur inserted basally of gonopore in shallow pit (Fig. 2B).
Holotype: Male, CHINA: Yunnan Province, Yonghsan Co., Huanghua Town, N 28° 00′E 103° 51′, 1500 m asl, 30 Oct 2010, reared on Zanthoxylum bungeanum, Wei Dong leg (SCAU). Paratypes: Same data as holotype, 27 males and 52 females paratypes (20 in SCAU, 55 in GC, 4 in SMT).
The species is so far known only from the Yunnan Province, Yonghsan Co., Huanghua Town, China.
Adult specimens of Arboridia sinensis sp. nov. were collected on Z. bungeanum at 1500 m, in Oct 2010. Postembryonic development consists of 5 immature instars (Figs 3A–F in Supplementary Material), that were observed during Sep and Oct 2010. Immature instars of A. sinensis sp. nov. live usually on the lower surface of the leaves of Z. bungeanum (Chinese prickly-ash, Sichuan pepper tree), whereas adults were observed also on other green parts of the host plant, such as leafstalks and fruits (Figs. 4A–F in Supplementary Material). Nymphs and adults are mesophyll feeders and their feeding cause symptomatic white-silver dechlorophyllation punctures on the leaves (Figs. 4B, 4C, 5C, 5D in Supplementary Material). The adults are attracted by yellow sticky traps (Fig. 5B in Supplementary Material). The host plant is economically important, because the bark and the berries of Z. bungeanum (Fig. 5A in Supplementary Material) are used for medicinal purposes. In particular, the fruit has remarkable anaesthetic, antihelmintic, astringent, diuretic and vasodilatory property. In addition, the dried fruit follicles of Z. bungeanum are used as a culinary spice and are particularly popular in Sichuan cuisine.
Nothing is known about the number of generations per year. In the natural environment, the populations of A. sinensis sp. nov. are controlled by natural enemies, among which are predators, such as spiders (Araneae), and parasitoids, such as Aphelopus alebroides Xu, Olmi, Guglielmino and Dong (Hymenoptera: Dryinidae) (Xu et al. 2011) (Figs. 6A, B in Supplementary Material). A. sinensis sp. nov. cohabits on Z. bungeanum with Empoasca (Matsumurasca) quadrialata Qin and Zhang, 2011 (Hemiptera: Cicadellidae).
Based on a similar shape of the pygofer process and the genital styles, A. sinensis sp. nov. has probably a close relationship with A. gaurii Thapa, 1989 described from Nepal and recorded on Zanthoxylum armatum (Thapa, 1989). In addition, both species feed on plants belonging to the same genus. The main differences between them consist in the coloration and markings of body (orange-brown in A. gaurii) and the aedeagus shape (see Thapa 1989, Figs. 7a, b, p. 118). The new species is probably related also to Arboridia cerna Dworakowska, 1977, and A. soror Dworakowska, 1977; both latter species were recorded in India. Arboridia cerna lives on Chinese cinnamon, Cassia sp. (Fabales: Fabaceae) and A. soror has been found on wormwood, Artemisia sp. (Asterales: Asteraceae) and on the orchid tree, Bauhinia sp. (Fabales: Fabaceae). In addition to the features mentioned above, the main difference between A. sinensis and the 2 Indian species concerns the shape of the pygofer process (see Dworakowska, 1977, Figs. 208–211, 216, 217, 221, 222, p. 302).
We are grateful to Dr. Irena Dworakowska for her important suggestions and help in the identification of the new species. We thank also Mr. Massimo Vollaro (University of Tuscia, Viterbo) for his assistance in preparing the plates. This study was supported by the Natural Science Foundation of China (No. U0936601).