Paralaevicephalus Ishihara

Xing, Jichun, Dai, Renhuai & Li, Zizhong, 2009, A taxonomic study of the genus Paralaevicephalus Ishihara (Hemiptera: Cicadellidae: Deltocephalinae), with description of four new species from China, Zootaxa 1979, pp. 53-61 : 53-54

Paralaevicephalus Ishihara

Paralaevicephalus Ishihara, 1953: 14 .

Khasiana Rao, 1989: 81, synonymized by Dai, Zhang et Hu, Paralaevicephalus Ishihara, 2005: 404 . Type species: Deltocephalus nigrifemoratus Matsumura, 1902 .

Description. Dirty yellow species, often with light veins on forewings. Head produced in front, slightly wider and longer than pronotum. Vertex triangular, each side near fore margin with oblique streak. Eyes black, fairly long and oblique; ocelli semitransparent, located on the lateral margin of vertex, separated from adjacent eye by approximately their own diameter. Face with dark, often confluent, transverse streaks. Frontoclypeus narrow, longer than width between eyes, anteclypeus slightly narrowed apically. Antennae arising near lower corner of eye. Pronotum with sides short, its anterior margin produced and posterior margin concave. Scutellum triangular, its length slightly shorter than length of pronotum, with transverse suture curved and depressed. Forewings with four apical cells and three subapical cells, 3.8–4.2 times as long as wide, apical cells sometimes with dark streaks, appendix well developed.

Male pygophore slightly longer than high, with several macrosetae on dorsal two thirds. Valve large, triangular. Subgenital plate short, with macrosetae irregularly arranged towards apex, with an elongate stout process from inner margin, directed posteriorly. Apical process of style short to long. Connective, loop-shaped with arms fused apically or Y-shaped with arms forked apically, stem present or absent. Aedeagal shaft short to elongate, without processes at apex, gonopore apical on ventral margin.

Size. Length (including tegmen): 2.7– 3.5 mm.

Diagnosis. This genus is similar to Laevicephalus DeLong in appearance, but can be distinguished from the latter by the unique subgenital plate, which has an elongate stout process arising from the inner margin, directed posteriorly, and by the aedeagal shaft without processes at the apex.

Distribution. China, Japan, Korea, India.

Discussion. Paralaevicephalus Ishihara is distributed in the Oriental and Palaearctic Regions. The genus belongs to the tribe Paralimini. In this group, the connective usually has the anterior branches fused apically. The form of the connective has long been considered a stable diagnostic trait that separates Paralimnini from other tribes of Deltocephalinae .

The four new species described below are the only known Paralimnini having a Y-shaped connective. This is the first report of such extensive variation in connective shape within one genus of Paralimnini . The new species would normally be placed in another tribe based on their having a Y-shaped connective, but they all belong to Paralaevicephalus based on the unique subgenital plate and the form of the aedeagus. The new species described in this paper represent the only known case where a single genus of Deltocephalinae includes some species with the anterior connective arms divergent and others with the arms fused.