Review of the planthopper genus Neodurium Fennah, 1956 (Hemiptera, Fulgoromorpha, Issidae)

Abstract The planthopper genus Neodurium Fennah is reviewed and Neodurium fennahi Chang & Chen, sp. n. (Hemiptera: Fulgoromorpha: Issidae) from China (Yunnan), is described and illustrated. A checklist of the species of Neodurium is given and a key provided for their separation. The female genitalia of Neodurium species are described for the first time.


Introduction
The Chinese planthopper genus Neodurium (Issidae) was established by Fennah (1956) for N. postfasciatum Fennah based on a female specimen from Hubei in China. Later, Ran et al. (2005) added information on the male genitalia for this species and described two more species. Subsequently, Zhang and Chen (2008) placed the genus in the Issidae, tribe Parahiraciini Cheng & Yang, and added further two new species. Then Wang and Wang (2011) described another new species. Accordingly the genus Neodurium is en-demic to China and currently comprises seven species including the species described below. The tribe Parahiraciini is endemic to Indo-Malayan Realm with few taxa distributed also in the Eastern Palaearctic Subrealm and comprises 14 genera (Gnezdilov 2013).
Herein, a further new species of Neodurium from China is described and illustrated, and all other species are reviewed. A checklist to the species of Neodurium is given together with a key for their separation. The female genitalia of the genus is described for the first time.

Material and menthods
The morphological terminology of the head and body follows Chan and Yang (1994), and the terminology of male and female genitalia follows Gnezdilov (2002) and Gnezdilov (2003). Dry specimens were used for descriptions and illustrations. External morphology was observed under a stereoscopic microscope. Measurements are given in millimeters. 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 were taken with a KEYENCE VHX-1000C.
The type specimens and other specimens are deposited in the following institutions whose names are abbreviated in the text as follows:

IEGU
The Institute of Entomology, Guizhou University, Guiyang, China.

BMNH
The Natural History Museum, London, UK.

IZCAS
Zoological Museum, Institute of Zoology, Chinese Academy of Sciences, Beijing, China. NWAFU The Entomological Museum, Northwest A & F University, Xi'an, China.

CAAS
The California Academy of Sciences, San Francisco, USA.
Coloration. General colour (Figs 1E, 2A-C) brown with pale mottling on the vertex and pronotum and base of frons. Eyes reddish brown to dark brown; antenna dark brown; frons ( Fig. 2B) with dark brown spot dorsomedially; clypeus brown to dark brown; rostrum dark brown. Forewings (Fig. 1E) with dark semicircular mark on clavus forming ovoid patch with wings at rest. Legs with tips of spines on hind tibiae and tarsi black.
Head and thorax. Head ( Fig. 2A) including eyes narrower than pronotum (0.74: 1.00). Vertex ( Fig. 2A) shorter in middle than the wide at base (0.70: 1.00), strongly dorsoventrally depressed; disc of vertex with one obscure median carina. Frons (Fig. 2B) flat, disc slightly depressed, basal margin arched in aute angle, apical margin obtusely rounded, lateral margin ridged, lateral margins of frons incurved below level of socket of antennae, longer in middle than the widest breath (1.00: 0.78), with median carina and lateral carina, lateral carina reaching to the level of antennae. Pronotum (Fig. 2B) with median carina and lateral carina, lateral carina not reaching to the posterior margin. Mesonotum ( Fig.  2A) triangular, with median carina and lateral carina. Hind tibiae each with one small spine near base and two distinct lateral spines, spinal formula of hind leg 8-14-2. Forewings ( Fig. 2D) long, subquadrate, 2.8 times as long as maximum width; longitudinal veins distinct, Sc+R vein long, reaching beyond half length of tegmen, Sc and R seperated near base, M vein divided into three branches, CuA vein (cubitus anterior) not forked, claval vein Pcu (postcubitus) and A 1 veins uniting in middle of tegmina. Hind wings (Fig.  2E) incised on apical margin into two lobes, anal lobe reduced, reticulate apically.
Male genitalia. Anal tube (Fig. 2G) relatively short, subquadrate in dorsal view, with two lobes near basal part, with four blunt lobes in apical margin. Anal column (Fig. 2G) short, located at the middle of anal tube. Pygofer (Fig. 2E) irregular subquadrate in lateral view, anterior margin moderately concave, posterior margin bended to ventro-lateral side. Genital styles (Fig. 2E) moderately long, dorsal margin producing a triangular inward lobe near capitulum; capitulum of style narrowing apically on short neck. Phallobase with dorsal lobe relatively long, not reaching the tip of lateral   lobe; with two pairs of strap-shaped processes (dorsal process) near base in lateral view (Fig. 2J) and one pair of processes intermediately connected, forming "H"-shaped bridge in dorsal view (Fig. 2I); ventral lobe long, apex weakly sinuate in ventral view (Fig. 2K); lateral lobe split into two branches in ventral view (Fig. 2K). Aedeagus with pair of long convergent hook-like processes (Fig. 2I).
Etymology. The new species is named for the memory of R.G. Fennah, who established the genus Neodurium.

Distribution. China (Yunnan).
Remarks. This species can be distinguished from other congeners by the dark oval patch on the forewings (Fig. 1E), phallobase with dorsal lobe (Fig. 2J) with two pairs of strap-shaped processes in lateral view (Fig. 2I).

Material examined. No specimens have been studied by the authors.
Remarks. This species was described after the holotype [1 male] from China (Hubei), deposited in IZCAS. Female genitalia. As in N. fennahi but hind margin of sternum VII (Fig. 4E) with more wider median concavity in ventral view. Anal tube (Fig. 4D) approximately oval, truncate apically, the widest breadth in the middle; anal colum located in the middle of anal tube. Anterior connective lamina of gonapophyses VIII (Fig. 4F) with 4 teeth bearing 4 keels in lateral group. Posterior connective lamina of gonapophyses ( Fig.  4G: b) IX with median field with a semicircular prominence (medial dorsal process); distal parts of posterior ventral lobes bent at slender angle, blade-like ( Fig. 4G: a).

Neodurium duplicadigitum Zhang & Chen, 2008
Remarks. This species was described from the holotype and paratypes from China (Yunnan), deposited in IEGU.

Material examined. No specimens have been studied by the authors.
Remarks. This species was described after the holotype [1 male] from China (Yunnan), deposited in IZCAS. Female genitalia. As in N. fennahi but hind margin of sternum VII (Fig. 5F) with wide median concavity in ventral view. Anal tube (Fig. 5E) approximately oval, truncate apically, the widest breadth in the middle; anal colum located in the middle of anal tube. Anterior connective lamina of gonapophyses VIII (Fig.  5G) with 4 teeth bearing 4 keels in lateral group. Posterior connective lamina of gonapophyses IX with median field with a bat-like prominence (medial dorsal process) (Fig. 5H: b); distal parts of posterior ventral lobes bent under broad angle, olecranon-shaped ( Fig. 5H: a).

Neodurium hamatum
Remarks. This species was described after the holotype [1 male] from China (Yunnan), deposited in NWAFU. Fennah, 1956 Figs 1C, 6 Neodurium postfasciatum Fennah, 1956: 513  Male genitalia. Anal tube (Fig. 6A, B) relatively short, subquadrate in dorsal view, with two lobes near basal part, with three lobes in apical margin, median lobe ship-like. Anal column (Fig. 6A, B) short, located at the middle of anal tube. Phallobase ( Fig.  6C) with dorsal lobe relatively long, not reaching the tip of lateral lobe, with fan-like process on dorsal margin, with small dentate tooth after fan-like process; lateral lobe split into two branches in lateral view, apical part with sharp tooth. Aedeagus (Fig. 6C) with pair of long hook-like processes in lateral view.

Neodurium postfasciatum
Remarks. This species was firstly described of females from China (Hubei), deposited in CAAS (Fennah 1956). It was subsequently redescribed including the male genitalia by Ran et al. (2005). Female genitalia. As in N. fennahi but anal tube (Fig. 7D) sub-rhomboid, apical part truncate then broad, the widest breadth at the basal 1/3; anal colum short moderately slender, located the basal 1/3 of anal tube. Anterior connective lamina of gonapophyses VIII (Fig. 7F) with 5 teeth bearing 5 keels in lateral group. Posterior connective lamina of gonapophyses IX with median field with a sub-quadrate prominence (medial dorsal process), apical part wavy ( Fig. 7G: b); distal parts of posterior ventral lobes bent at slender angle, blade-like ( Fig. 7G: a).

Neodurium weiningensis
Remarks. This species was described after the holotype and paratypes [three males and four females] from China (Guizhou), deposited in IEGU.

Discussion
Compared with the structure of male genitalia of this genus, we found that in the structure of the male genitalia N. hamatum differs significantly from other species of the genus by the following characters: genital styles without a hook-like process on the dorsal margin in lateral view (Fig. 5D); anal tube without two sub-basal lobes (Fig.  5A), without other lobes on apical margin in dorsal view and without various process ventrally in lateral view (Fig. 5B); anal column long and slender. Possibly N. hamatum belongs to another subgenus. On the other side, according to the female genitalia of this genus, N. hamatum is distinctly different from other species as follows: Anterior connective lamina of gonapophyses VIII short, relatively broad (Fig. 5G). Posterior connective lamina of gonapophyses IX broad, distal parts of posterior ventral lobes bent under broad angle, olecranon-shaped (Fig. 5H). These characters also show that the above assumption seemed reasonable.
However, how much value does the female genitalia have in Parahiraciini? Hamilton (2011) stated that the ovipositor was an important character in Fulgoroidea and the female genitalia of Issidae have attracted increasing attention in recent years with some important characters being identified by Gnezdilov (2003Gnezdilov ( , 2014. However, little information has been reported for Parahiraciini, except for Bardunia, Flavina, Folifemurum, Narinosus, Scantinius and Tetricodes (Gnezdilov 2011, Zhang et al. 2010, Che et al. 2013, Gnezdilov and Wilson 2005, 2007, Fennah 1956). Although, Che et al. (2013) discussed relationships within Parahiraciini with respect to characters of the vertex, forewings and hind wings, much still remains to be done to using the female genitalia.