Three new species of the leafhopper genus Tambocerus Zhang & Webb (Hemiptera, Cicadellidae) from southern China

Abstract Three new species, Tambocerus dentatus, T. longicaudatus and T. robustispinus spp. n. from southern China, are described and illustrated. A checklist and distribution to the Tambocerus species from China is provided together with a key for their separation.


Introduction
The Oriental leafhopper genus Tambocerus was established by Zhang and Webb (1996) with Selenocephalus disparatus (Melichar, 1903) from Sri Lanka as its type species. It was placed in the tribe Selenocephalini (Zhang and Webb 1996) due to the transverse striations on the fore margin of the head but was assigned to the tribe Athysanini in the subfamily Deltocephalinae by Viraktamath (2012) according to the key to tribes of the subfamily Deltocephalinae (Zahniser and Dietrich 2008). Zhang and Webb (1996) originally described the genus Tambocerus for two species, Tambocerus disparatus (Melichar) and T. plumbeus (Distant) from Sri Lanka. Rao (1996) added one new species from Indian, Shen et al. (2008) described four more species from China and Viraktamath (2012) described seven new species from the Indian subcontinent. So far, the genus Tambocerus contains 14 known species.
In this paper, we describe three new species, Tambocerus dentatus Qu & Dai, sp. n., T. longicaudatus Qu & Dai, sp. n. and T. robustispinus Qu & Dai, sp. n. from China, are described and illustrated. A checklist along with distribution records and a key to distinguish species of the genus from China are provided.

Material and methods
Classification system follows that by Zahniser and Dietrich (2013), morphological terminology follows that by Zhang and Webb (1996), Shen et al. (2008) and Viraktamath (2012).
Type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC) and one specimen of Tambocerus robustispinus sp. n. is deposited in the British Museum (Natural History), London, U.K. (BMNH).
Remarks. This genus can be differentiated from other genera by the following combination of characters: ocelli on margin close to eye, vertex slightly produced medially with anterior margin transversely striate, antennae located at level near to middle of eyes, connective Y-shaped with stem as long or longer than arms and aedeagal shaft laterally serrate.
Distribution. Palearctic and Oriental region: Sri Lanka, Indian and China.

Key to species of the genus Tambocerus from China (males)
1 Pygofer caudal lobe rounded with dorsoposterior margin dentate (Fig. 10) Aedeagal shaft without bifurcate apex, with pair of lateral subapical process (Shen et al. 2008: Fig. 28 Morphology. Head (Fig. 1) including eyes nearly as wide as pronotum; vertex produced anteriorly with midlength 1.5 times length next to eyes. Fore tibia with dorsal setal formula 1+4.
Male genitalia. Pygofer (Figs 10, 12) with elongate lateral hyaline band and quadrate hyaline area on dorsal bridge; lobe with several long macrosetae dorsally and dor- sal margin and apex serrated; valve (Fig. 11) semicircular; subgenital plate ( Fig. 11) evenly tapered from base to acute apex with several short stout setae laterally; style (Fig. 15) relatively slender, with short and narrow lateral lobe, apophysis long, half length of style, serrate over inner margin; connective ( Fig. 15) with stem twice length of arms; aedeagal shaft (Figs 13-14) abruptly constricted and curved dorsally near base in lateral view, distally laterally compressed with a medial subapical keel on the ventral surface, lateral margins serrate, with a short subapical processes on each side of ventral surface; phallobase well developed; dorsal apodeme short without lateral arms.
Remarks. This species externally resembles Tambocerus elongatus Shang and Zhang but can be separated from the latter by the male pygofer (Figs 10, 12) without process; the subgenital plate (Fig. 11) tapering from base to end; the aedeagal shaft  without depression at subapex in lateral view.
Etymology. This species name is derived from the Latin word "dentatus", referring to the dentate dorsal margin of the pygofer lobe. Description. Body colour. Body yellow-brown with dark brown patches and eyes fuscous or black.
Male genitalia. Pygofer (Figs 16,19) with elongate lateral hyaline band and pair of lobe-like hyaline areas on dorsal bridge (Fig. 19), lobe with few long macrosetae dorsally at base, lobe well produced process-like with apex digitate and curved ventrally; valve (Fig. 17) triangular; subgenital plate ( Fig. 17) abruptly narrowing at midlength, apical half slender with few short setae; style (Fig. 18) with short and broad subapical lobe, apophysis moderately long, digitate with inner margin dentate subapically; connective (Fig. 22) Y-shaped with stem one and a half times length of arms; aedeagal shaft (Figs 20-21) compressed dorsoventrally, dentate laterally over distal half to near apex, with pair of apical dorsolateral serrated processes approximately half length of shaft; phallobase well developed; dorsal apodeme with short robust arms.
Etymology. The new species name is derived from the Latin words "longus" (long) and "caudatus" (tail), indicating the long pygofer extension.  Morphology. Head (Fig. 7) including eyes slightly wider than or nearly equal to pronotum; vertex slightly produced anteriorly with midlength 1.2 times length next to eyes. Fore tibia with dorsal setal formula 1+5 or 1+6.

Tambocerus robustispinus
Male genitalia. Male pygofer (Figs 23,26) with elongate lateral hyaline band and semi crescent-shaped hyaline area on dorsal bridge, lobe (Figs 23, 26) with fine dorsal setae, lobe produced and tapered to acute apex with fine dorsal setae; valve (Fig. 24) triangular; subgenital plate ( Fig. 24) gradually tapered to midlength thereafter with finger-like apex, with several short setae; style ( Fig. 25) with short and narrow lateral lobe and moderately long apophysis dentate apically; connective ( Fig. 30)  Etymology. This species is named for the stout apical processes of the aedeagal shaft.