Taxonomic study of the leafhopper genus Oncopsis (Hemiptera, Cicadellidae, Macropsinae) from Sichuan Province, China with description of two new species and a key to males

Abstract This paper deals with the leafhopper genus Oncopsis (Macropsinae) from Sichuan Province of China, and describes and illustrates two new species, O.konkaensissp. nov. from Minya Konka (Sichuan), and O.moxiensissp. nov. from Moxi Town (Sichuan), and provides a key to males and a geographic distribution map for Oncopsis species from Sichuan.


Introduction
The leafhopper genus Oncopsis Burmeister, 1838 includes more than 90 members ) around the world, and is the second largest group in the subfamily Macropsinae (Hemiptera: Cicadellidae). Oncopsis has been treated as a tribe of the subfamily Eurymelinae recently (Dietrich and Thomas 2018), and has a distribution mostly in the Holarctic region. The type species is Cicada flavicollis Linnaeus, 1761. Oncopsis differs from other macropsine genera in having the face with coronal pits closer together than the ocelli, the usually transversely striate pronotum, the male pygofer without a process, and the s-shaped male dorsal connective that is usually produced into various processes from its inner ventral margin.
In the present paper, the genus Oncopsis from Sichuan Province, China is reviewed, and two new species, O. konkaensis, sp. nov. from Minya Konka and O. moxiensis, sp. nov. from Moxi Town, are described and illustrated. A geographic distribution map and a key for identification of Oncopsis from Sichuan Province (based on male features) are provided.

Materials and methods
Specimens were collected by sweep net. External morphology was observed under an Olympus SZX7 and BX43 microscopes. Male genitalia preparations were made by placing the whole abdomen in a boiling solution of 8% NaOH for 5 minutes, then rinsing with fresh water several times and transferring into glycerin on glass slides for examination, dissection, drawing, and photography. The dissected genitalia and remains of the abdomen were stored in micro vials containing glycerin for further examination.
Habitus images of adults were obtained with an Olympus SZX7 microscope associating with a Canon EOS 550D camera. Genitalia drawings were made and edited with Adobe Illustrator CS6 and Photoshop CS6.
The morphological terminology used in this work for the species descriptions follow the works of Anufriev (1967), Hamilton (1980), and Tishechkin (2017). The body length was measured from the apex of the head to the end of the forewings and is given in millimeters.
The type specimens of the new species are deposited in the Museum of Zoology and Botany, Shaanxi University of Technology, Hanzhong, China (SUHC), and the other examined specimens are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).
Etymology. The specific epithet was derived from the type locality, Minya Konka (Sichuan Province), where the species was collected, combined with the Latin suffix -ensis, meaning from a locality. Description.
Male genitalia. Pygofer side broad basally (Fig. 7), dorsal and caudal margin truncated, ventral margin with distal half expanded inwards, with scattered setae. Subgenital plate (Fig. 8) slender, 0.6 × length of ventral margin of pygofer. Aedeagus (Figs 11,12) with broad basis, slender shaft, tapered to subacute end in lateral aspect, margins somewhat parallel, with round apex in ventral view, gonopore subapical. Dorsal connective (Fig. 13) s-shaped in lateral view, produced to large and long process from inner ventral margin bent ventrad beyond mid-length, apex bifurcate. Style (Fig. 14) with stout stem, dorsally bent, gradually widening to apex, with marginal setae, apical margin truncated. Connective (Figs 15, 16) typical of the genus. Measurement. Body length (including tegmen): 5.0 mm. Distribution. Sichuan (Fig. 65). Host. Betula spp. (Betulaceae). Remark. The new species differs from all other known members of Oncopsis by the unique shape of the dorsal connective, which has the medial process large and long, bent ventrad and bifurcated at the apex; also by the combined features of the aedeagus and pygofer.

Oncopsis melichari Lauterer & Anufriev, 1969
Oncopsis melichari Lauterer & Anufriev, 1969: 163. Material examined. None. Distribution. Sichuan. Note: the distribution of O. melichari is excluded from the distribution map since the collected data, "the valley of the river Shubagu" of the original record (Lauterer and Anufriev 1969), cannot be matched with any known place names. Etymology. The specific epithet was derived from place name, Moxi Town, where the species was collected and the type locality is located, combined with the Latin suffix -ensis, meaning from a locality.
[Holotype] Body color. Background yellow brown. Crown (Fig. 4) dark brown. Face (Fig. 6) yellow brown to dark brown, eyes brown, marked with reddish; antenna yellowish brown; frons dark to black except on ocelli and middle line; clypeus with central area dark or black on both sides of middle line, distal half chocolate. Pronotum (Fig. 4) dark brown with evenly dispersed darker spots. Scutellum and legs coloration similar to O. konkaensis sp. nov. Forewing (Figs 5, 6) with basal half dark brown and distal half yellowish brown.

Host. Betula spp. (Betulaceae).
Remark. This species is similar to Oncopsis konkaensis sp. nov. in the body coloration and external morphology, and somewhat similar in the shape of the dorsal connective, but can be distinguished from the latter by the different coloration of the face, and the shapes of the aedeagus, style and the dorsal connective.