Three new species of the genus Czernyola Bezzi, 1907 (Diptera, Clusiidae) from China

Abstract The following three species assigned to the Czernyola biseta group of the genus Czernyola Bezzi, 1907, from China are described as new to science: C. luteigenissp. nov., C. planipalpissp. nov., and C. shanxiensissp. nov. A key to the known species of Czernyola from China is provided.


Introduction
Czernyola Bezzi, 1907, belongs to the subfamily Clusiodinae, which is assigned to the family Clusiidae. The genus is characterized by the following characteristics: four or five fronto-orbitals; the third fronto-orbital seta from back inclinate and the remainder reclinate, most posterior fronto-orbital seta sometimes small or minute; mid tibia with 2 dorsal preapical setae and hind tibia with 1 dorsal preapical seta; surstylus smooth with sparse setae or setulose on the outer surface anteriorly; ejaculatory apodeme wide and flared at the end, appearing mushroom-shaped; distiphallus large, membranous and sac-like, sometimes strongly reduced or absent; hypandrial arm with a weak membranous attachment to the remainder of the hypandrium (Lonsdale and Marshall 2006). There are 59 described species distributed worldwide, of which one species is distributed in the Palaearctic Region and 20 species are distributed in the Oriental Region (Lonsdale 2017). Only one species, Czernyola biseta (Hendel, 1913) has been recognized from China (Hendel 1913;Hennig 1941;Frey 1960). McAlpine (1960) divided the genus into three species groups: Czernyola transversa, C. concinna, and C. biseta. The C. transversa group is best identified on the four reclinate fronto-orbitals, united cerci, and elongate basiphallus with atrophy of the distiphallus and the ejaculatory apodeme. The C. concinna group is considered a weakly supported clade, based on four fronto-orbitals of approximately equal lengths and often the presence of the prescutellar acrostichal seta (Lonsdale and Marshall 2006). Sasakawa (2010) established the C. hyalina group, based on the length of the anterior dorsocentral seta and the shape of the surstylus.
In this paper three new species assigned to the C. biseta group are described based on the small hind fronto-orbitals and anterior dorsocentral seta, as well as the characteristics of the cerci and surstylus.

Materials and methods
Genitalia preparations were made by removing and macerating the apical portion of the abdomen in glacial acetic acid, then rinsing in distilled water before storage in glycerin-filled microvials. After examination, genitalia were transferred to fresh glycerin and stored in a microvial on the pin below the specimen or moved to an ethanol tube together with the wet specimens. Specimens examined were deposited in the Entomological Museum of Henan Agricultural University (HAU), Zhengzhou. The general terminology follows Lonsdale and Marshall (2006). The M 1 ratio is defined as the length of the ultimate section of wing vein M divided by the length of the penultimate section (Lonsdale and Marshall 2006).

Taxonomy
Key to Chinese species (males) of Czernyola Diagnosis. Head mostly yellowish; postgena with a single well-developed seta. Scutum dark yellow, mesonotum with dark brown subtriangular marking. Abdomen dark brown, anterior half of tergite I yellow. Surstylus with four distal tubercules. Pregonite with large distal lobe, distal 3/5 setulose, 1 medial seta.

Distribution. China (Tibet).
Etymology. The specific name refers to the yellow gena. Remarks. This new species is somewhat similar to Czernyola varicolor (Sueyoshi), but differs in the surstylus bearing apical tubercules and the pregonite having obvious setae. In C. varicolor the surstylus has no apical tubercules, and the pregonite is without obvious medial setae (Sueyoshi 2006 Diagnosis. Head brown to darkish brown; first flagellomere entirely white or dark brown. Scutum yellow with brown shield-like marking at middle. Surstylus without tubercles. Pregonite thin, with 3 strong setae nearly equal in length and many microsetulae. Description. Male. Body length 2.9 mm, wing length 2.4 mm. Head (Fig. 7) brown, postgena slightly lighter; frons brown; occiput darkish brown; gena ~ 1/6 as high as eye. Setae yellowish and setulae black, four fronto-orbital setae, hind seta short; genal setae and vibrissa thin. Antenna yellowish, first flagellomere yellowish white, pedicel setose with distinctly long setae dorsally. Arista sparsely short plumose. Palpus brown.
Dark phase (China: Tibet): externally as described for pale phase except as follows: head much darker black; antennae dark yellow, first flagellomere dark brown. Scutum dark yellow, with brown shield shape slightly bigger and scutellum dark brown. Medi- otergite much darker brown. Thoracic pleura yellowish. Anepisternum and katepisternum brown much darker. Mid and hind leg with femora and tibiae yellower.
Remarks. This new species is somewhat similar to Czernyola atrifrons (Malloch), but differs in having a yellow scutum with brown markings; in C. atrifrons the head is brown to dark brown, the vibrissa is small and the anterior half of tergite I is yellow (Steyskal and Sasakawa 1966).

Female. Unknown.
Distribution. China (Shanxi). Etymology. The specific epithet refers to the type locality. Remarks. Czernyola shanxiensis can be separated from other species of this genus by the genitalia, as there are entirely divided cerci, the surstylus is without tubercules, and pregonite is thin, and it has 2 strong setae of equal length,1 smaller seta, and many microchaetae.