Two new species in the genus Kuvera Distant, 1906 (Hemiptera, Cixiidae, Cixiinae) from China

Abstract Two new species (Kuverahuoditangensissp. n. and Kuveralongwangshanensissp. n.) in the family Cixiidae from China are described and illustrated. The generic characteristics are redefined. A checklist to all species of Kuvera worldwide and an identification key to the Chinese species are provided. A map of the geographic distribution of Kuvera species is also provided.


Introduction
Cixiidae is the largest family of planthoppers in the world (slightly larger than the Delphacidae), with nearly 2500 described species (Bourgoin 2018). Some cixiids are economically important pests that feed on crops and vector plant pathogens such as: Hyalesthes obsoletus Signoret, 1865, Reptalus (Proreptalus) quinquecostatus (Dufour, 1833) and Myndus taffini Bonfild, 1983, causing serious economic losses (Julia 1982;Sforza et al. 2010;Pinzauti et al. 2010). Even though this family is very large and important, Cixiidae from the Oriental Region has not been studied extensively.
In this paper, we describe and illustrate two new Chinese species of the genus Kuvera: K. huoditangensis sp. n. and K. longwangshanensis sp. n., and we found K. vilbastei Anufriev, 1987 for the first time in Tibet, China. We also have provided an amended genus description. A checklist to all worldwide species of Kuvera is provided as well as a map of their geographic distribution. We also have developed a key for the Chinese species of Kuvera. Differences between K. flaviceps (Matsumura, 1900) and K. longwangshanensis sp. n. are briefly described.

Materials and methods
All materials, including holotypes of the new species, were deposited in the Entomological Museum of Northwest A&F University (NWAFU), Yangling, Shaanxi Province, China. Most of their geographical distribution data is based on the localities recorded in the literature, and the rest of the data is based on the collection localities of the specimens examined, which are deposited in Entomological Museum of NWAFU. The updated distribution data is presented in the checklist and on the map.
The morphological terminology and measurements follow Bourgoin et al. (2015) for the venation patterns of the tegmen and Tsaur et al. (1988), Löcker et al. (2006) and Bourgoin (1993) for male and female genitalia.
Measurements of external body length are the distance between the apex of the vertex to the tip of the forewing. Measurements of the vertex length are the distance between the apical transverse carina to the most caudal limits of the vertex.
External morphology was observed using a light LEICA Zoom 2000 microscope. To prepare male genitalia for dissection, specimens were softened for 12h in a humid glass cylinder. The genital segments of specimens were then dissected and macerated in hot 10% NaOH solution overnight or by boiling for 3 to 5 min. The genital segments were then rinsed in distilled water and transferred into PVC microvials containing glycerol. Tissues were immersed in glycerin on slides for drawing. The anal segment and pygofer were drawn. Images were made using a LEICA MZ12.5 stereoscope fitted with a drawing tube and mirror. Photographs of specimens were taken with a Scientific Digital micrography system equipped with an Auto-montage imaging system and a QIMAGING 4000R digital camera (CCD) and imported into Adobe Photoshop CC for labeling and plate composition.

Key to the known species (males) of Kuvera from China
Coloration. General color black. Body slightly covered with powdery wax (Fig.  1). Eyes dark brown, ocelli milky white. Antenna and rostrum generally dark brown (Fig. 2). Vertex brown with yellow carinae. Frons dark brown near base with lateral carinae yellow brown to pale brown from latero-basal angles to ends of frontoclypeal suture, clypeus black (Fig. 4). Pronotum shallow brown with darker areas. Mesonotum black with 3 dark brown carinae (Figs 1, 4). Tegmina hyaline with veins yellowish and dark brown granules, pterostigma blackish brown. Forewings with a small irregular, roundish spot on anterior branch of Y-vein (Figs 1, 3). Legs and abdomen yellowish brown.
Male terminalia. Pygofer with a sub-triangular lateral margin; in dorsal view, asymmetrical, with a triangular medioventral process (Figs 5, 6, 14, 15). Anal segment in lateral view slender, straight at basal part; in dorsal view asymmetrical, longer than broad, widening to middle then narrowing, rounded to apex. Anal style sits subapically (Figs 7, 8, 16, 17). Genital styles symmetrical, in lateral view with hook-shaped apex, parallel-sided at basal half (Figs 9, 18). Aedeagus with 3 spinose processes, in ventral view, periandrium narrow near middle, with 2 spinose processes, one comparatively short, arising near base of flagellum, apex curved and directed cephalad. Another process comparatively long, implanted on left side near mid-length of periandrium, S-shaped, curved from left side to right side and then to middle of periandrium, apex curved 120 degrees and directed left-cephalad (Figs 13, 19). In dorsal view, flagellum with a small and short spine extending from middle, reaching apex of the sclerotized portion of flagellum, directed cephalad. Tip of flagellum near base of periandrium (Figs 10, 22). Periandrium asymmetrically widened at base, slightly curving to left. In ventral view, caudal margin of basal segment of periandrium convex, medially with two teeth, lateral apical angle with two teeth near distal portion (Figs 13, 19).
Female terminalia. Unknown. Etymology. This species epithet is named after the type locality Huoditang.

Distribution. China (Shaanxi).
Remarks. This new species is similar to K. vilbastei but can be separated by the following characteristics: (1) the process implanted on the left side near the mid-length of periandrium (K. huoditangensis has a long and S-shaped spinose process, curved from the left side to the right side and then to the middle of the periandrium, apex curved 120 degrees and directed left-cephalad, but K. vilbastei has a long spinose process, curved from the left side to the right side, across the shaft sub-apically, apex curved 90 degrees and directed cephalad, not reaching the base of the periandrium); (2) the process extending from the middle of the flagellum (K. huoditangensis has a small and short spine, reaching the apex of the sclerotized portion of flagellum, but K. vilbastei has a stout and long spine, reaching the middle of the membranous portion of flagellum); and (3) the basal segment of periandrium (K. huoditangensis asymmetrically widens in dorsal view, slightly curving to the left, caudal margin of the basal segment of the periandrium convex, medially with two teeth, but K. vilbastei symmetrically widens, in ventral view, caudal margin of the basal segment of periandrium convex and serrated).  Description. Body length: male 5.1-5.6 mm (n=3), forewing length: male 5.2-5.3 (n=3).
Coloration. General color black. Body slightly covered with powdery wax (Fig. 23). Eyes dark brown, ocelli white. Antenna and rostrum generally dark brown (Fig. 24). Vertex brown, apical margin of vertex and surroundings yellow (Fig. 26). Frons dark brown, apical and lateral margins of frons yellowish brown, adjacent area of middle carinae near middle to frontoclypeal suture dark, and V-shaped, frontoclypeal suture and clypeus blackish brown, median carina yellowish (Fig. 24). Pronotum dark brown with yellowish areas. Mesonotum black with 3 dark brown carinae (Figs 23,26). Tegmina hyaline with veins brown and yellow brown granules, pterostigma blackish brown. Forewings with a small irregular, roundish spot on anterior branch of Y-vein (Figs 23, 25). Legs brown, abdomen dark brown.
Male terminalia. Pygofer with lateral margin sub-triangular in outline; in dorsal view, asymmetrical, wider than long, with a triangular medioventral process (Figs 27,28,36,37). Anal segment in lateral view slender, widening in the middle and then narrowing, rounded at the apex; in dorsal view asymmetrical, longer than broad, narrow near base, expanded sub-apically (Figs 29, 30, 38, 39). Genital styles symmetrical, in lateral view with hook-shaped apex, inner margin deeply concave but outer margin rounded (Figs 31, 40). Aedeagus with 3 spinose processes, in ventral view, periandrium narrow near middle, with 2 spinose processes, the length of shorter spinose process about two-thirds of the longer spinose process. The longer one implanted on the left side near the mid-length of periandrium, gently curved from left to right side, apex curved over shaft and towards the right side. The shorter one arising near base of flagellum, touching shaft apically, apex curved and directed ventrally (Figs 32, 41). In dorsal view, flagellum with a stout and long spine extending nearly one-third the length of flagellum, the length of this spine more than two-thirds that of the longest spinose process, directed cephalad. The tip of flagellum reaches the base of the periandrium (Figs 35, 44). Periandrium asymmetrically widens at base, slightly curving to left. In ventral view, caudal margin of the basal segment of the periandrium convex, medially with a tooth, lateral apical angle with two teeth near the distal portion (Figs 32, 41).
Female terminalia. Unknown. Etymology. This species epithet is named after the type locality Longwangshan.

Distribution. China (Zhejiang).
Remarks. This new species is similar to K. flaviceps, but can be separated by the following characteristics: (1) in dorsal view, the process implanted on the left side near the mid-length of the periandrium (K. longwangshanensis has a long spine, gently curved from left side to right side, apex curved over the shaft and to the right side, but K. flaviceps has a long spine, gently curved from the left to right side, apex not reaching the right lateral margin of the periandrium); (2) the process arising near the base of the flagellum (K. longwangshanensis has a shorter spine, touching the shaft apically, apex strongly curved mesad and directed ventrally, but K. flaviceps has a spine not touching the shaft apically, apex slightly curved and directed cephalad); and (3) the process of the flagellum (K. longwangshanensis has a stout and long spine extending nearly one-third the length of flagellum, the length of this spine is more than two-thirds of the longest spinose process, directed cephalad; but K. flaviceps has a thinner and shorter spine extending from the middle of flagellum, this spine is about half the length of the spinose process). Anufriev, 1987 Figs 45-50 Kuvera vilbastei Anufriev, 1987: 7, figs 17-22. Type material. 1 male, China, Tibet Autonomous Region, Bomi Country, Yigong (29°85'N, 95°79'E), 2300m a.s.l, 29.VII.1978; 1 male, China, Tibet Autonomous Region, Yadong Country (27°55'N, 88°93'E), 2800m a.s.l, 24.VIII.1978.
Remarks. Based on the description and figures by Anufriev (1987), this species can be distinguished from other species in this genus by following characters: Pygofer with subtriangular lateral margin; with a triangular medioventral process. Anal segment in lateral view slender, straight at basal part; in dorsal view, asymmetrical, about 3 times longer than broad, slightly widening at middle, rounded at apex. Anal style sits subapically (Figs 46,47). Genital styles symmetrical, in lateral view with hook-shaped apex (Fig. 48). Aedeagus with 3 spinose processes, in dorsal view, periandrium narrow near middle, with 2 spinose processes, one comparatively short, arising near the base of flagellum, apex curved and directed cephalad. Another one comparatively long, implanted on the left side near the mid-length of periandrium, curved from left to right side, curving across the shaft subapically, apex curved 90 degrees and directed cephalad, not reaching the base of the periandrium. Flagellum with a stout and long spine extending from the middle, reaching the middle of the membranous portion of flagellum, directed cephalad. Flagellum reaching the base of the periandrium (Fig. 45). Periandrium symmetrically widened at base, caudal margin of the basal segment of the periandrium convex and serrated, lateral apical angle with two teeth near the distal portion (Figs 49,50). (Matsumura, 1900) Oliarus flaviceps Matsumura, 1900: 208. Kuvera flaviceps Matsumura, 1914 (Fig. 2).
Remarks. Based on the description and figures by Matsumura (1914) and Anufriev (1987), this species can be distinguished from other species in this genus by the following characters: Pygofer has a lateral margin with a subtriangular outline; in dorsal view, asymmetrical, wider than long, with a triangular medioventral process. Anal segment in lateral view slender; in dorsal view asymmetrical, longer than broad, with convex lateral margins, rounded apically. Genital styles symmetrical, in lateral view with hook-shaped apex. Aedeagus has 3 spinose processes, in dorsal view, periandrium narrows near middle, with 2 spinose processes. A spine is implanted on the left side near the mid-length of the periandrium, which gently curves from the left side to right side, apex not reaching the right lateral margin of the periandrium. Another spine arises near the base of flagellum, not touching the shaft apically, apex curved and directed cephalad. Flagellum with a stout and long spine extending from the middle, this spine is about half as long as the longest spinose process, directed cephalad. Flagellum reaches the base of the periandrium.

Discussion
The biology of Kuvera species throughout the world have not been extensively studied. According to our collection surveys, these species are primarily found on grass, trees, shrubs and forbs, ranging in altitude from 0 to 3000 m a.s.l. The plant associations of Kuvera have been described in several previous studies. Anufriev (1987) described cedar and birches as the primary host plants of K. vilbastei and K. pallidula. Emeljanov (2015) listed the following host plants for K. ussuriensis and K. flaviceps: myrica (Myrica L.), Nanking cherry (Cerasus tomentosa (Thunb.) Wall.), birches (Betula platyphylla Suk.) and alder (lnus japonica (Thunb.) Steud.). We also found members of this genus on the cedar (Cedrus deodara (Roxb.) G. Don).
As part of ongoing monitoring studies in Chinese agroecosystems, we collected specimens of Cixiidae from crop plants, trees, forbs, shrubs and weeds in locations primarily in Southern China. We found that K. huoditangensis sp. n. occurs in Ningshan County, which is on the southern slope in the middle of the Qingling Mountain range. The specimens were collected in Huoditang Teaching and Experimental Forest Farm of Northwest A&F University of Ningshan County at an elevation between 1400 to 1500 m. Kuvera longwangshanensis sp. n. occurs in the Longwang Mountain National Nature Reserve (LNNR) of Anji County in the northwest of Zhejiang Province at 200 to 1500 m a.s.l. LNNR is located in the hinterland of the Yangtze River Delta and is covered by virgin forests. In the LNNR, the specimens were collected on Longwang Mountain at an elevation between 1000m and 1200m.
The Kuvera genus is distributed in eastern Asia, central Asia and the Indo-Malayan region (Fig. 51). Most Kuvera species occur in the Oriental region of the world: China (Sichuan, Zhejiang, Taiwan, south of Qinling Mountain in Shaanxi), India and Myanmar. Some species of Kuvera mainly occur in adjacent regions in the northeast Palaearctic such as Primorsk, Khabarovsk, and the Kuriles (eastern Russia); Hokkaido (northern Japan); and the Korean Peninsula. A few species of Kuvera occur in the southwest Palaearctic such as the Tibet Autonomous Region (western China) and the Hindu Kush (eastern Afghanistan). We anticipate that additional species of Kuvera will be found in countries throughout the primary distribution range of this genus.