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

Bing Zhang; Meng Mao; Ding Yang

doi:10.3897/zookeys.876.33163

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.) acuminatum sp. nov., E. (E.) henanensis sp. nov., and E. (E.) longitubum sp. 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.

Keywords

Limnophilinae, morphology, description, key

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).

The following 12 species were previously known from China: Sichuan: E. (E.) bicinctiferum Alexander, 1935, E. (E.) subobsoletum Alexander, 1936, E. (E.) sultanum Alexander, 1938; Zhejiang, Hubei: E. (E.) evanescens Alexander, 1940; Taiwan: E. (E.) divisum Alexander, 1923, E. (E.) kempi Brunetti, 1913, E. (E.) nymphicum Alexander, 1928; Yunnan: E. (E.) ancistrum Mao & Yang, 2009, E. (E.) breve Mao & Yang, 2009, E. (E.) elongatum Mao & Yang, 2009, E. (E.) mediale Mao & Yang, 2009, E. (E.) yunnanense Mao & Yang, 2009. Of these 12 species, ten are endemic to China, E. (E.) evanescens being also known from Japan and E. (E.) kempi from Japan, India, and Sri Lanka. Here three new species are added to the fauna of China, as well as E. (E.) insigne, known previously only from Indonesia and Malaysia. An updated key to the species of the subgenus E. (Epiphragma) from China is presented.

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).

Taxonomy

Key to species of subgenus Epiphragma from China

1	Femora unpatterned (Fig. 7)	2
–	Femora patterned (Figs 1–6)	3
2	Origin of Rs with short spur (Figs 12, 15); m-cu at basal 1/4 of cell dm	E. (E.) divisum (Alexander, 1923)
–	Origin of Rs without spur (Fig. 14); m-cu at basal 3/4 of cell dm (Fig. 14)	E. (E.) insigne (van der Wulp, 1878)
3	Femora black or yellow with one subterminal ring	4
–	Femora yellow with two dark brown rings (Figs 1–6)	8
4	Femora black with narrow yellow subterminal ring; verticils on antenna shorter than segments	E. (E.) sultanum (Alexander, 1938)
–	Femora yellow with darker subterminal ring; verticils on antenna longer than segments	5
5	Femora with broad black subterminal ring; prescutum with narrow black median stripe obsolete for some distance before suture	E. (E.) nymphicum (Alexander, 1928)
–	Femora with pale brown subobsolete ring before tip; prescutum not as above	6
6	Dark pattern of wing without narrow dark brown margin	E. (E.) subobsoletum (Alexander, 1936)
–	Dark pattern of wing with narrow dark brown margin	7
7	R₂₊₃₊₄ nearly straight, in virtual longitudinal alignment with Rs; m-cu strongly sinuous	E. (E.) evanescens (Alexander, 1940)
–	R₂₊₃₊₄ not as above; m-cu straight	E. (E.) kempi (Brunetti, 1913)
8	Dark pattern of wing without narrow dark brown margin (Fig. 13)	9
–	Dark pattern of wing with narrow dark brown margin (Figs 12, 14, 15)	10
9	Spur at origin of Rs almost obsolete; apical half of interbase like a slender rod bent at a 90-degree angle from thickened base	E. (E.) mediale (Mao & Yang, 2009)
–	Spur at origin of Rs distinctly longer (Fig. 13); apical half of interbase finger-shaped (Figs 26, 27)	E. (E.) henanensis sp. nov.
10	Interbase very long, at least as long as gonocoxite	11
–	Interbase relatively short, shorter than gonocoxite	15
11	Second ring of femora at tip (Figs 1, 2, 5, 6)	12
–	Second ring of femora near tip (Figs 3, 4)	14
12	Aedeagus 4/5 as long as gonocoxite (Figs 38, 39)	E. (E.) longitubum sp. nov.
–	Aedeagus less than 4/5 as long as gonocoxite (Figs 20, 21)	13
13	Crossvein m-cu at basal 1/4 of cell dm; interbase finger-shaped	E. (E.) elongatum (Mao & Yang, 2009)
–	Crossvein m-cu at basal 1/3 of cell dm (Fig. 12); interbase S-shaped (Figs 20, 21)	E. (E.) acuminatum sp. nov.
14	Base of interbase subtriangular; inner gonostylus with several setae at tip	E. (E.) bicinctiferum (Alexander, 1935)
–	Base of interbase triangular, connected with one small ellipsoidal hole; inner gonostylus without setae at tip	E. (E.) yunnanense (Mao & Yang, 2009)
15	Pronotum light brown without any black stripe; hyaline spots of wing rather small; median area of tergite 9 with small prominence; inner gonostylus setae, with tip curved into small spine	E. (E.) ancistrum (Mao & Yang, 2009)
–	Pronotum brown with one black stripe; hyaline spots of wing rather large; median area of tergite 9 plane without small prominence; inner gonostylus with obtuse tip and several setae at base	E. (E.) breve (Mao & Yang, 2009)

Epiphragma (Epiphragma) acuminatum sp. nov.

http://zoobank.org/8D097E94-414F-4B15-8E28-99EF59F9637D

Figs 1, 2, 8, 12, 16–21

Diagnosis

Generally brownish yellow with pale gray pruinosity. Femora yellow with two dark brown rings, first at basal 2/3, second at tip, broader. Wing brownish hyaline with conspicuous brown pattern, chiefly spotted, with narrow dark brown margin, brownish hyaline areas large. Origin of Rs obtuse and curved with short spur; m-cu at basal 1/3 of cell dm. Interbase with long and slender rod beyond base, longer than gonocoxite, apex with sharp point; whole slender rod S-shaped. Aedeagus 1/2 as long as gonocoxite, sword-tip shaped.

Description

Male. (n = 3): Body length 11.5–13.0 mm, wing length 12.0–14.0 mm, antenna length 2.5–2.7 mm. Head (Figs 1, 8). Brownish yellow with pale gray pruinosity except orbit pale yellow. One median tubercle between eyes. Setae on head black. Scape and pedicel brown, flagellum 13-segmented with two basal segments fused, fusion-segment yellow, succeeding segments brownish, flagellomeres cylindrical, apical segments elongate, with longer verticils. Proboscis brownish black with black setae; palpus black with black setae.

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; R₂₊₃₊₄ longer than R₂₊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 (Figs 16–21). Posterior margin of tergite 9 (Figs 16, 19, 20) with subtrigonal lobe on each side of median V-shaped notch. Base of outer gonostylus (Figs 17, 19–21) broad, tip curved into spine. Base of inner gonostylus (Figs 18–21) with setae, tip obtuse and curved up. Interbase (Figs 20, 21) with long and slender rod beyond base, longer than gonocoxite, apex with sharp point; whole slender rod S-shaped. Aedeagus (Figs 20, 21) half as long as gonocoxite, sword-tip shaped.

Figures 1–6.

1, 2 Epiphragma (Epiphragma) acuminatum sp. nov. 3, 4 Epiphragma (Epiphragma) henanensis sp. nov. 5, 6 Epiphragma (Epiphragma) longitubum sp. nov. 1, 3, 5 male habitus, lateral view 2, 4, 6 female habitus, lateral view. Scale bars: 1 mm.

Figure 7.

Epiphragma (Epiphragma) insigne (van der Wulp, 1878). Male habitus, lateral view. Scale bar: 1 mm.

Female. (n = 19): Body length 12.6–14.0 mm, wing length 12.8–14.2 mm, antenna length 2.5–2.7 mm. Similar to male. Cerci reddish brown; hypovalves brown (Fig. 2).

Type Material

Holotype male (CAU), China: Ningxia, Jingyuan, Liupanshan, Liangdianxia, 2007.VI.28, Gang Yao (light trap). Paratypes: 2 males, 8 females (CAU), China: Ningxia, Jingyuan, Liupanshan, Liangdianxia, 2007.VI.28, Gang Yao (light trap); 2 females (CAU), China: Ningxia, Jingyuan, Liupanshan, Liangdianxia, 2007.VI.27, Gang Yao (light trap); 8 females (CAU), China: Ningxia Yinchuan Helanshan Suyukou, 2007. VII. 5, Gang Yao; 1 female (CAU), China: Ningxia, Jingyuan, Liupanshan, Liangdianxia, 2007.VII.15, Gang Yao (light trap).

Distribution

China (Ningxia).

Etymology

The specific name refers to the interbase narrowing to a slender point.

Remarks

This new species is somewhat similar to E. (E.) sultanum 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).