Two new species of the genus Ptychoptera Meigen, 1803 (Diptera, Ptychopteridae) from Yunnan, China with remarks on the distribution of Chinese species

Abstract Sixteen known species of the genus Ptychoptera Meigen, 1803 have been recorded from China, of which three occur in Yunnan Province. Herein, two new species from Yunnan, P.cordatasp. nov. and P.yunnanicasp. nov., are described from China. An updated key to Ptychoptera is presented for all Chinese species.

Diagnosis. Postnotum dark brown, mediotergite with a cordiform yellow spot; wing marked with two brown bands; apical process of paramere semilunar, apex expanding outward; lateral extension of terminal division of hypandrium triangular with a pair of semicircular lobes medially, terminal division of hypandrium umbelliform.
Vertex and frons brown; face and clypeus yellow with light brown hairs; gena yellow with a black elliptical spot medially, hairs on gena brown; occiput yellow. Compound eyes black without pubescence. Scape, pedicel and basal 2/3 of 1 st flagellomere yellow, remaining flagellomeres brown, setae dark brown. Proboscis light yellow with light brown hairs. Palpus yellow with last segment gradually darked apically, hairs brown. Thorax (Fig. 1a, b). Pronotum and propleuron light yellow. Prescutum, scutum and paratergite uniformly black. Scutellum mostly dark brown, middle area yellow with a patch of dense brown hairs. Mediotergite of postnotum dark brown, middle area with a cordiform yellow spot. Laterotergite half brown, outer half yellow with dense dark brown hairs, in dorsal view. Mesopleuron and metapleuron uniformly yellow. Coxae and trochanters yellow; femora yellow with brown ring apically; tibiae yellow with brown ring apically; 1 st tarsomere of fore and hind legs yellow brown with brown ring apically. Hairs on legs brown. Wing (Fig. 1c) 3.7 times as long as wide, subhyaline, marked with two brown bands as follows: median band extending from basa of Rs to middle section of CuA 2 ; subapical band extending from tip of R 1 , cover- ing pterostigma and extending to tip of M 2 . Veins brown; Sc ending in C at level of basal 1/3 of R 2+3 ; Rs straight, slightly shorter than r-m; r-m arise from R 4+5 . Halter and prehaltere pale yellow with brown hairs. Abdomen (Fig. 1a). First tergum yellow with caudal 1/5 light brown, 2 nd tergum yellow with middle area and caudal 1/6 brown, 3 rd and 4 th terga yellow with posterior margin brown, 5 th tergum yellow with caudal 1/2 brown, 6 th and 7 th terga brown with posterior margin yellow. Sterna yellow. Hairs on abdomen brown.
Male genitalia (Fig. 2) yellow. Epandrium ( Fig. 2b) bilobed, epandrial lobe broad, epandrial clasper tapering and curved ventrally to the middle, slender apically, with brown hairs; epiproct with short hairs. Gonocoxite (Fig. 2c) long and stout, 3.3 times as long as wide, basal apodeme small; apical process of paramere semilunar, apex expanding outward. Gonostylus (Fig. 2c): anterior lobe of basal lobe of gonostylus on inner side with dense long hairs; medial lobe of basal lobe of gonostylus tongue-shaped with dense short hairs on posterior margin; secondary lobe of apical stylus of gonostylus finger-shaped with dense short hairs; apical stylus of gonostylus finger-shaped with short hairs. Hypandrium ( Fig. 2d): basal scale of hypandrium dumbbell-shaped basally with several hairs; spathate lobe of hypandrium broad at base with dense long hairs on inner side, hook-shaped apically with short hairs on posterior margin; basal division of hypandrium finger-shaped with dense long hairs on inner side; lateral extension of terminal division of hypandrium triangular with a pair of semicircular lobes medially; terminal division of hypandrium umbelliform. Aedeagus (Fig. 2e, f ): subapical sclerite tongue-shaped, apex of subapical sclerite round; aedeagal sclerites with apex laterally compressed, with dorsal corner extended anterodorsally, straight sided and convergent, base broad; lateral ejaculatory processes with base straight, narrow, extended straight anterolaterally; discoid apodemes with elongate ovoid dorsal extension; sperm sac subspherical; ejaculatory apodeme flag-like, closely associated with aedeagal sclerites, larger than sperm sac, paralleling anterior margin of sperm sac.
Remarks. This new species is similar to P. formosensis from China and Japan but can be separated from the latter by the postnotum dark brown with a cordiform yel- low spot, the apical stylus of the gonostylus finger-shaped, and the apical process of paramere semilunar with apex expanding outward. In P. formosensis, the postnotum is uniformly black, the apical stylus of the gonostylus is flat tongue-like, and the apical process of the paramere is bilobed (Nakamura and Saigusa 2009). This new species is also similar to P. annandalei Brunetti, 1918 from Burma, but can be separated from the latter by the apical process of paramere semilunar with apex expanding outward, the apical stylus of the gonostylus and the secondary lobe of the apical stylus of the gonostylus finger-shaped, not crossing. In P. annandalei, the apical lobes of the paramere are dorsoventrally flattened and semicircular with the spine curved anteriorly, apices of the apical stylus and secondary lobe of the gonostylus are crossing (Fasbender 2014). This new species is also similar to P. perbona Alexander, 1946 from Burma, but can be separated from the latter by the mediotergite with a cordiform yellow spot, the apical stylus of the gonostylus finger-shaped, the apex of the terminal division of the hypandrium with an umbelliform lobe. In P. perbona, the mediotergite is uniformly black, the apical stylus of the gonostylus is stylate, the apex of the terminal division of the hypandrium has a pair of needle-like lateral lobes (Alexander 1946;Fasbender 2014). Diagnosis. Postnotum dark brown, mediotergite with a big yellow spot; wing marked with three weak brown clouds at tip of R 1 , fork of R 4+5 and fork of M 1+2 and a brown band extending from basal of R 2+3 to middle section of CuA; subapical spine of epandrium transverse conical; basal scale of hypandrium rectangular, anterior margin strongly concaved medially, basal division of hypandrium finger-shaped with dense long hairs basally and medially; terminal division of hypandrium cordiform.
Description. Male. Body length 6.5-8.0 mm, wing length 7-7.5 mm. Vertex and frons dark brown with brown hairs; face and clypeus yellow with light brown hairs; gena yellow with a black elliptical spot medially, hairs dark brown; occiput yellow. Compound eyes black without pubescence. Scape, pedicel and basal 1/2 of 1 st flagellomere yellow, remaining flagellomeres brown, setae on antenna dark brown. Proboscis light yellow with brown hairs. Palpus yellow with terminal of last segment brown, hairs brown. Thorax (Fig. 3a, b). Pronotum and propleuron light yellow. Prescutum, scutum and paratergite uniformly black. Scutellum mostly brown, middle area yellow with a patch of dense dark brown hairs. Mediotergite of postnotum dark brown, middle area with a big yellow spot. Upper half of laterotergite dark brown, lower half of laterotergite yellow, with brown hairs, in dorsal view. Mesopleuron and metapleuron uniformly yellow. Coxae and trochanters yellow; fore femur yellow and gradually darkened apically; mid and hind femora yellow with brown ring apically; tibiae yellowish brown with brown ring apically; 1 st tarsomere of fore and mid legs brown, 1 st tarsomere of hind leg yellow with a narrow dark brown ring apically, other tarsomeres dark brown. Hairs on legs dark brown. Relative length of 1 st to 5 th tarsomeres in hind leg as 7: 2: 1.2: 1: 1. Wing (Fig. 3c) 3.8 times as long as wide, subhyaline, marked with three brown clouds and a brown band as follows: three weak brown clouds at tip of R 1 , fork of R 4+5 and fork of M 1+2 ; median band extending from basa of Rs to middle section of CuA 2 . Veins brown; Sc ending in C not at level of basal 1/3 of R 2+3 ; Rs straight, slightly longer than r-m; r-m arise from R 4+5 . Halter and prehaltere pale yellow with brown hairs. Abdomen (Fig. 3a). First tergum dark brown with basal 1/5 yellow, 2 nd tergum yellow with middle area and caudal 1/6 dark brown, 3 rd tergum yellow with caudal 1/5 dark brown, 4 th tergum yellow with caudal 1/4 dark brown, 5 th to 7 th terga dark brown. Sterna yellow. Hairs on abdomen brown.
Remarks. This new species is similar to P. persimilis Alexander, 1947 from Burma, but can be separated from it by have a mediotergite with a big yellow spot, the subapical spine of the epandrium transverse conical, the apical process of the paramere hookshaped with the apex incurvated. In P. persimilis, the mediotergite does not have a big yellow spot, only the adjoining portion of the scutellum is yellow; the epandrium is nematoform, the apex is expanded and slipper-like, the paramere has elongate, ribbon-like spines directed posterior, crossing medially (Alexander 1947;Fasbender 2014). This new species is also similar to P. praescutellaris Alexander, 1946 from Burma, but can be separated from it by having the subapical spine of the epandrium transverse conical, and the secondary lobe of the apical stylus finger-shaped. In P. praescutellaris, the apex of the epandrial clasper is bulbous and without a conical projection, and the secondary lobe of the apical stylus is subtrapezoidal (Alexander 1946;Fasbender 2014). This new species resembles somewhat P. emeica from China but can be easily separated from the latter by the postnotum dark brown with a big yellow spot, the basal 1/3 of the yellow second abdomen tergum with a median brown spot, the subapical spine of the epandrium transverse conical, and the medial lobe of the basal lobe of the gonostylus finger-shaped. In P. emeica, the postnotum is uniformly black, the basal 1/3 of the second tergum of the abdomen is uniformly brown, the epandrium has no transverse conical subapical spine, and the medial lobe of the basal lobe of the gonostylus is broad and tongue-shaped (Kang et al. 2019). Finally, the new species can be separated from P. lushuiensis from China by the postnotum dark brown with a big yellow spot, the subapical spine of the epandrium transverse conical, the apical process of the paramere hook-shaped with the apex incurvated, and the terminal division of the hypandrium cordiform. In P. lushuiensis, the postnotum is uniformly black, the surstylus of the epandrium does not have a transverse conical subapical spine, the apical process of paramere is sclerotized triangular, and the terminal division of hypandrium cordiform is X-shaped (Kang et al. 2013).

Distribution of Ptychoptera species in China
In total, 18 species of Ptychoptera are recorded from China. According to Fasbender (2014), the Ptychoptera fauna of China is a complex of the P. tibialis group, the P. contaminata group, the Southeast Asian Ptychoptera and unplaced species. One species, P. separata, is endemic to Tibet, China and belongs to the P. tibialis group, which otherwise is mainly distributed in the Indian Subcontinent. Two species, P. lucida and P. yankovskiana, can clearly be characterized as species of the P. contaminata group and are distributed in the East Palaearctic region. Twelve Southeast Asian Ptychoptera species, namely P. bannaensis, P. bellula, P. circinans, P. cordata, P. emeica, P. formosensis, P. gutianshana, P. lii, P. longwangshana, P. lushuiensis, P. wangae, P. yunnanica are widely distributed in Southwest and East China. Ptychoptera qinggouensis has the same characteristics as species of Southeast Asian Ptychoptera and is distributed in Inner Mongolia. Two species with insufficient material or illustrations for placement, P. clitellaria and P. xinglongshana, are distributed in Gansu and Sichuan, respectively (Fig. 5).