Notes on black elytron species of Pyrrhalta Joannis and the description of a new species from China (Coleoptera, Chrysomelidae, Galerucinae)

Abstract Thirteen species of Pyrrhalta Joannis, 1865 with black elytron are reviewed. A key to species, photographs of aedeagus and habitus are provided. Pyrrhalta qianana sp. n. is described from Guizhou, China. Pyrrhalta martensi Medvedev & Sprecher-Uebersax, 1999 is newly recorded from China (Tibet).


Introduction
The genus Pyrrhalta Joannis, 1865 is a large, worldwide genus distributed in the Holarctic, Oriental and Australian Regions. The genus was firstly proposed as a subgenus of Galeruca Geoffroy, 1762 by Joannis (1865), and Galeruca viburni Paykull, 1799 was deemed to be fixed as type species by monotypy. The genus presents serious difficulties in several aspects of its classification and nomenclature. Firstly, this genus is very large

Material and methods
Morphological characters were examined with an Olympus SZ 61 microscope. Genitalia of males and / or females of each species were dissected using the following procedure: for dried or ethanol preserved specimens, the abdomen was separated, transferred to a vial containing 10% KOH which was heated in a boiling water bath for 10 min. The genitalia were then carefully removed in a cavity slide under distilled water using fine forceps and hooked minuten-pin dissecting needles. Series of partially focused photographs were made with a digital camera (Nikon D300S) attached to a stereomicroscope (Zeiss Discovery V12), and then combined using Helicon Focus software, and finally were evaluated and assembled using Adobe Photoshop CS 8.0 and Illustrator CS4 software. Notes. Holotype of this species was diagnosed as male in the original description without being dissected (Chen 1942). Actually the holotype is female. Its spermatheca is illustrated here (Fig. 42). The updated catalogue of Galerucinae (Beenen 2010) Figures 1-12. Habitus. 1-2 P. fossata (holotype) 3-4 P. huangshana (holotype) 5-6 P. martensi (paratype) 7-8 P. meghalayana (paratype) 9-10 P. metallica 11-12 P. orientalis (holotype).
showed that this species belonged to a subgenus Neogalerucella of Galerucella. In this study, we found that the disc of pronotum is entirely covered by hairs. So we think that this species should be remained in Pyrrhalta.
Distribution. China (Zhejiang). Notes. Aedeagus is illustrated here for the first time. Aedeagus: slender, dorsal view: strongly asymmetrical, apex with acute tip, apical part narrower than basal part, gradually tapering apically but arching near half of base on right side, nearly straight on left side before apex; lateral view: very slender, nearly straight on left side, suddenly tapering to acute tip at basal 1/4 on right side (Figs 38-39).   , 1800-1900m, 14-VIII-1957.

Pyrrhalta warchalowskii
Diagnosis. This species can be separated from all known species in the genus by the following characters: very long antennae (length=4.9 mm), antennomere 3 more than 2 times as long as antennomere 2, and last abdominal sternite of male with very deep U-shape cavity (Fig. 46).
Description. Generally black, apex of labrum and mandible, maxilla, dark brown; head, pronotum, elytral margin, elytral suture, yellowish; antenna black except ventral side of antennomeres 1-5; legs brown except ventral sides of tibiae and tarsi black; scutellum yellowish brown, dark brown on basal part. Body densely covered with short pale silvery pubescences.
Scutellum trapezoid, densely punctured, sparsely pubescent. Elytron subparallel, nearly 3.7× as long as broad, maximum width across both elytra 1.15 mm, linear distance from base to apex of elytra 4.25 mm; surface confusedly punctured and closely covered with fine hairs; space between punctures smaller than diameter of puncture; epipleuron slightly broad basaly, gradually narrowed toward apex.
Ventral surface: mesoventrite glabrous, mesepisternum and mesepimeron thinly covered with short pubescence. Middle disc of metaventrite brown, with sparse hairs. Last sternite of male with very deep "U" shape emarginate cavity reaching nearly its basal margin.
Legs moderately stout, hind tarsomere 1 nearly equal with last which is nearly as long as 2 and 3 together. Male. Last abdominal sternite with very deep U-shape cavity (Fig. 46). Aedeagus: dorsal view: strongly asymmetrical but nearly parallel-sided, apex subacute, tapered; lateral view: somewhat sinuate on left side, gradually tapering to acute tip on right side. (Figs 48-49). Female. Last abdominal sternite with triangle emargination at center of apex (Fig.  45). Spermatheca: base not bent, capsule wall thick, apex of capsule about 1/2 as long as capsule (Fig. 47).
Etymology. This species is named for its holotype locality, Guizhou province (shortened form as "Qian" in Chinese).

Discussion
Pyrrhalta is a species rich, worldwide distributed genus with complex classification and nomenclature. The relationships of Pyrrhalta and related genera (Galerucella, Neogalerucella, Xanthogaleruca, and Tricholochmaea) are still unclear. The updated catalogue of Galerucinae treated Galerucella, Xanthogaleruca, and Tricholochmaea were as valid genera and Neogalerucella as subgenus of Galerucella (Beenen 2010). To explore true relationship of these groups, a thorough revision of Pyrrhalta is necessary. Considering that subgenera currently are very poorly defined, we will separate the genus into several artificial groups and produce a series of revisionary works. In this study, we have reviewed Pyrrhalta species with black elytra. Based on the current morphological work with thirteen species of Pyrrhalta with black elytra two types of internal sac were found. One is with comb-shaped sclerites and another one lacking the sclerites. Comb-shaped sclerites presents in P. sulcatipennis and P. subaenea. They are absent in the rest of the studied species including P. orientalis which is placed in Xanthogaleruca in the updated catalogue of Galerucinae (Beenen 2010). Therefore, comb-shaped internal sac cannot be used to distinguish Xanthogaleruca and Pyrrhalta. The proper status of Xanthogaleruca could not resolve until a thorough revision of Pyrrhalta is done. We still need to find reliable characters to identify above related groups. It may be necessary to combine traditional morphological methods with molecular and biological methods to achieve this goal.