Two new species of the bamboo-feeding leafhopper genus Abrus Dai & Zhang (Hemiptera, Cicadellidae, Deltocephalinae) from China

Abstract Two new species of the bamboo-feeding genus Abrus Dai & Zhang, 2002, Abrus xishuiensis sp. n. and Abrus langshanensis sp. n., are described and illustrated from Guizhou and Hunan, South China. A checklist and a key to 13 known species are given.


Introduction
The bamboo-feeding leafhopper genus Abrus was established by Dai and Zhang (2002) with six species from Hunan, Guangxi, Fujian, Guangdong and Gansu of China (type species: Abrus hengshanensis Dai & Zhang, 2002). To date, 11 species are recognized in the genus (Dai and Zhang 2002;Li and Wang 2006;Dai and Zhang 2008;Li et al. 2011) from southern China. Of them, A. brevis Dai & Zhang, A. coneus Dai & Zhang and A. leigongshanensis Li & Wang, were recorded feeding on bamboo (Li et al. 2011).
During on-going studies on species biodiversity of the bamboo-feeding leafhoppers in China, some specimens belonging to undescribed species of the genus Abrus were found. The purpose of this paper is to describe two new species and to provide an identification key to the known species of Abrus.

Material and methods
In the present paper, terminology follows Li et al. (2011). Dry specimens were used for the description and illustration. External morphology was observed under a stereoscopic microscope and characters were measured with an ocular micrometer. Measurements are given in millimeters; body length is measured from the apex of the head to the apex of the forewing in repose. The genital segments of the examined specimens were macerated in 10% KOH, washed in water and transferred to glycerine. Illustrations of the specimens were made with a Leica MZ 12.5 stereomicroscope. Photographs of the types were taken with a Leica D-lux 3 digital camera. The digital images were then imported into Adobe Photoshop 8.0 for labeling and plate composition. The type specimens and material examined are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (IEGU).

World checklist of species of Abrus Dai & Zhang
Coloration. Orange to yellowish brown (Figs 1-5). Crown with two pairs of similar blackish brown spots on anterior margin, along suture pale reddish orange. Eyes blackish brown, anterior angle pale reddish brown. Pronotum with pair blackish brown spots on anterior part, with short pale reddish orange stripe centrally. Scutellum with reddish orange marking centrally, transverse suture pale reddish orange. Inner and central anteapical cells at apex, third and fourth apical cells at base each with a dark brown spot.
Head and thorax. Crown length 0.7× medial width between eyes. Pronotum length 1.93× medial length of crown. Scutellum length 0.93× medial length of pronotum. Forewing length 3.87× medial width at widest part.

Distribution. Southwest China (Guizhou).
Remarks. This species resembles A. biprocessus Li, 2011 in appearance, but can be distinguished by body size ♂ 9.02-9.25 mm, ♀ 9.35-9.90 mm (♂ 8.1 mm, ♀ 8.2 mm in biprocessus); pygofer with one process at posteroventral corner (with two processes in biprocessus); basal projection of aedeagus with apical appendages stout and short (slender and long in biprocessus); subapical appendages of aedeagal shaft branched at apex, without a small branch basally (not branched at apex, with a small branch at basal third in biprocessus). Etymology. This species is named after the type locality, Langshan, Xinning, Hunan Province in China.
Coloration. General color pale yellowish orange (Figs 13-17). Crown with two pairs of similar blackish brown spots on anterior margin. Eyes blackish brown, ocelli pale yellowish white. Face pale yellowish white. Inner and central anteapical cells at apex, third and fourth apical cells at base each with a dark brown spot.
Head and thorax. Crown medial length 0.58× width between eyes. Pronotum length 2.03× medial length of crown. Scutellum length 0.87× medial length of pronotum. Forewing length 4.00× medial width at widest part.

Distribution. South China (Hunan).
Remarks. This new species is similar to A. breviolus Dai & Zhang, 2008 in aedeagus having reduced or small basal projection dorsally, but can be distinguished by posterior margin of male pygofer without process (with stout process dorsally in breviolus); apical margin of subgenital plate rounded (truncate in breviolus); aedeagal shaft with apex hook-like, without pair of subapical appendages (with pair of subapical appendages laterally in breviolus).