New species of the subgenus Epiphragma Osten Sacken from China (Diptera, Limoniidae)

Abstract Previously 12 species of the subgenus Epiphragma (Epiphragma) Osten Sacken, 1860 were known to occur in China. The following three species are described and illustrated as new to science: E. (E.) acuminatumsp. nov., E. (E.) henanensissp. nov., and E. (E.) longitubumsp. nov.. Epiphragma (E.) insigne van der Wulp, 1878 is reported from China for the first time and is illustrated based on additional morphological characters. An updated key to the species of the subgenus E. (Epiphragma) from China is presented.


Introduction
The subgenus Epiphragma (Epiphragma) Osten Sacken is the largest subgenus in the genus Epiphragma, with 115 known species, and is considered to be monophyletic (Ribeiro 2008). It is distributed worldwide with ten species from the East Palaearctic, 27 species from the Oriental Region, five species from the Nearctic Region, 64 species from the Neotropical Region, and 14 species from Australasian/Oceanian Region (Oosterbroek 2019). It is delimited by the following combination of characters: flagellum with two or more basal segments fused; wing broad, variegated with brown bands, spots; a single supernumerary cross-vein in cell C; posterior margin of tergite 9 with subtrigonal lobe on each side of median notch (Dienske 1987).

Materials and methods
The specimens were studied and illustrated with a ZEISS Stemi 2000-c stereo microscope. Genitalic preparations were made by macerating the apical portion of the abdomen in cold 10% NaOH for 12-15 h. After examination in glycerin, genitalia were transferred to fresh glycerin and stored in a microvial pinned below the specimen. The type specimens of the new species are deposited in the Entomological Museum of China Agricultural University (CAU), Beijing, China.
Terminology of morphological features generally follows that of McAlpine (1981) except wing veins which follow Dienske (1987).
Thorax (Figs 1, 8). Generally brownish yellow with pale gray pruinosity. Pronotum and prescutum brownish yellow. Prescutum with four black stripes, intermediate pair long and almost extended to transverse suture. Scutum brownish black, intermediate brownish yellow, scutellum and mediotergite brownish yellow. Pleura brown, variegated by brownish yellow areas. Setae on thorax brown. Coxae and trochanters yellow; femora yellow with two dark brown rings, first at basal 2/3, second at tip, broader; tibiae brown with one spur; tarsi brown. Setae on legs brown except coxae with brownish yellow setae. Wing (Figs 1, 12). Brownish hyaline with conspicuous brown pattern, chiefly spotted, with narrow dark brown margin, brownish hyaline areas large. Base of wing brown, connected with two large ocellate circles with flattened tips; one circle along cord connected with second circle. Stigma solidly dark brown. Origin of Rs obtuse and curved with short spur; R 2+3+4 longer than R 2+3 ; m-cu at basal 1/3 of cell dm. Halter 1.7-1.8 mm long, brownish black except base of stem yellow and apex of knob pale yellow. Setae on wings brownish yellow. Abdomen (Fig. 1). Tergites 1-5 brownish yellow; tergites 6-9 brownish black. Sternites 1-5 grayish yellow, both sides brownish yellow; sternites 6-9 brownish black. Setae on abdomen brown. Hypopygium . Posterior margin of tergite 9 (Figs 16,19,20) Alexander, 1938 from China (Sichuan) in having a similar shape of the hypopygium, but it can be separated from the latter in having the femora yellow with two dark brown rings, the origin of Rs obtuse and curved with a short spur, and m-cu at basal 1/3 of cell dm. In E. (E.) sultanum, the femora are black brown with a narrow yellow ring; the origin of Rs is obtuse and without a spur; and m-cu is at basal 1/2 of cell dm (Alexander 1938 Figs 3,4,9,13,[22][23][24][25][26][27] Diagnosis. Generally brown with gray pruinosity. Vertex with one median brown line. Femora yellow with two brown rings, first at basal 2/3, second at before tip, longer than yellow tip. Wing brownish hyaline with conspicuous brown pattern, chiefly spotted, without narrow dark brown margin. Origin of Rs obtuse and sharp with long spur; m-cu at basal 1/2 of cell dm. Interbase with long and slender rod beyond base, almost as long as gonocoxite, apex with sharp point, whole slender rod finger-shaped. Aedeagus 1/2 as long as gonocoxite, sword-tip shaped. Description. Male. (n = 27): Body length 8.5-10.5 mm, wing length 9.6-12.0 mm, antenna length 1.2-1.8 mm. Head (Figs 3, 9). Brownish yellow. Vertex with one brown median line. One median tubercle between eyes. Setae on head black. Scape and pedicel dark brown, flagellum 13-segmented with two basal segments fused, fusion-segment yellow, succeeding segments dark brown, flagellomeres cylindrical, apical segments elongate, with longer verticils. Proboscis brownish yellow with black setae; palpus black with black setae. Thorax (Figs 3,9). Generally dark brown with pale gray pruinosity. Pronotum brown with one brownish yellow stripe. Prescutum brownish with four dark brown stripes, intermediate pair long, with lateral, humeral and anterior parts brown. Scutum and scutellum brown. Mediotergite black brown. Pleura brown, variegated by dark brown areas. Setae on thorax black brown. Coxae pale brown; trochanters brownish yellow; femora yellow with two brown rings, first at basal 2/3, second near tip, longer than yellow tip; tibiae brownish yellow with one spur; tarsi brownish yellow with bright yellow tip. Setae on legs black brown. Wing (Figs 3, 13). Brownish hyaline with conspicuous brown pattern, chiefly spotted, without narrow dark brown margin. Base of wing brown, connected with two large ocellate circles with flattened tips; one circle along cord connected with second circle, each tip of vein with brown spot. Stigma solidly dark brown. Origin of Rs obtuse and sharp with long spur; R 2+3+4 longer than R 2+3 ; m-cu at basal 1/2 of cell dm. Halter 1.1-1.6 mm long, brownish black except base of stem yellow and apex of knob brownish yellow. Setae on wings brownish yellow. Abdomen (Fig. 3). Tergites brown with median brownish stripe, both sides with black brown lines. Sternites brownish yellow. Last three segments black brown. Setae on abdomen black. Hypopygium (Figs 22-27 Female. (n = 57): Body length 8.6-12.0 mm, wing length 9.5-12.3 mm, antenna length 1.2-1.8 mm. Similar to male. Cerci reddish brown; hypovalves reddish yellow (Fig. 4).  Mao & Yang, 2009 from China (Yunnan) in having a similar shape of the hypopygium, but it can be separated from the latter by the wing pattern without narrow dark brown margin, the origin of Rs with a long spur, and m-cu at basal 1/2 of cell dm. In E. (E.) elongatum, the pattern of the wing has a narrow dark brown margin; the origin of Rs has a short spur; and m-cu is at basal 1/4 of cell dm (Mao and Yang 2009 Diagnosis. Generally brown with gray pruinosity. Vertex with one median brown line. Femora yellow without ring. Wing brownish hyaline, with conspicuous brown pattern, chiefly spotted, without narrow dark brown margin; one long irregular hyaline band cross whole wing from tips of veins R 3 , R 4 , ending at cell A 1 ; hyaline areas large. Origin of Rs obtuse and curved without spur; R 2+3+4 three times longer than R 2+3 ; m-cu at basal approximately 3/4 of cell dm. Interbase with base expanded, shorter than gonocoxite, but longer than aedeagus, apical rod slender, C-shaped, bent to sternite, tip curved into slender spine. Aedeagus very short and small.  Description. Male. (n = 1): Body length 9.0 mm, wing length 9.8 mm, antenna length 1.7 mm. Head (Figs 7, 10). Brownish yellow. Vertex with one black median line. One median tubercle between eyes. Setae on head black. Scape and pedicel black brown, flagellum 13-segmented with two basal segments fused, fusion-segment yellow, brown at tip; femora yellow without ring; tibiae yellow with one spur; tarsi yellow. Setae on wings brownish yellow. Wing (Figs 7, 14). Brownish hyaline, with conspicuous brown pattern, chiefly spotted, without narrow dark brown margin; base of wing brown; each tip of vein with brown spot; one long irregular hyaline band across whole wing from tips of veins R 3 , R 4 , ending at cell A 1 ; hyaline areas large. Origin of Rs obtuse and curved without spur; R 2+3+4 three times longer than R 2+3 ; m-cu at basal approximately 3/4 of cell dm. Setae on wings brownish yellow. Halter 1.2 mm long, brownish yellow except base of stem yellow and apex of knob pale yellow. Setae on legs brownish yellow.
Thorax (Figs 5,11). Generally brown with pale gray pruinosity. Pronotum brownish yellow with one dark blackish brown stripe. Prescutum brown with two brownish yellow stripes, one yellow line at middle. Scutum yellow. Scutellum and mediotergite brownish yellow. Pleura brown, variegated by light yellow areas. Setae on thorax brown. Coxae and trochanters yellow; femora yellow with two dark brown rings, first at basal 2/3, second at tip, broader; tibiae brown with one spur; tarsi brown. Setae on legs brown except coxae and trochanters with brownish yellow setae. Wing (Figs 5, 15). Brownish hyaline with conspicuous brown pattern, chiefly spotted, with narrow dark brown margin, brownish hyaline areas large. Base of wing brown, connected with two large ocellate circles with flattened tips; one circle along cord connected with second circle. Stigma solidly dark brown. Origin of Rs obtuse and curved with short spur; R 2+3+4 longer than R 2+3 ; m-cu at basal 1/3 of cell dm. Halter 2.1 mm long, brown except base of stem and apex of knob pale yellow. Setae on wings brownish yellow. Abdomen (Fig. 5). Tergites 1-3 brownish yellow; tergites 4-9 brownish black, with one brownish yellow middle line. Sternites 1-5 brownish yellow; sternites 6-9 brownish black. Setae on abdomen brownish yellow. Hypopygium (Figs 34-39