Sepedon plumbella Wiedemann, 1830

Li, Zhu & Yang, Ding, 2017, Sepedon (Diptera: Sciomyzidae) species from China, with notes on taxonomy and distribution, Zootaxa 4254 (3), pp. 301-321 : 312

5. Sepedon plumbella Wiedemann, 1830

( Figs. 41–51 )

Sepedon plumbella Wiedemann, 1830 . Ausser. Zweifl. Ins. 2: 577. Type locality: China.

Sepedon sanguinipes Brunetti, 1907 . Rec. Indian Mus. 1: 215. Type locality: Java, Soerabaya.

Diagnosis. In males ( Fig. 41 ), fore tibia swollen apically with a distinct long seta; fore basitarsus distinctly twisted, with distinct groove ( Fig. 44 ), but normal in females ( Fig. 42 ). Frons shiny dark brown except for yellow anterior margin between antennae ( Fig. 43 ). Orbital spots and parafacial velvety black spots absent ( Fig. 45 ); frons with pair of posterior orbital setae. All antennal segments concolorous, blackish brown ( Fig. 45 ). Thorax mainly black except yellow upper margin of pleuron. Scutellum with pair of apical scutellar setae. Wing infumated, usually with darker anterior portion and apex. Female similar to male in external characters except for fore basitarsus and terminalia.

Male terminalia: Sternum 5 narrow, divided into two transverse sub-oblong sclerites ( Fig. 46 ). Cercus short and small ( Fig. 47 ). Surstylus bilobed, with triangular lateral sides basally ( Fig. 47–48 ). Hypandrium symmetrical and irregular ( Fig. 49 ). Cochleate vesicle present ( Fig. 47–48 ). Aedeagus and apodemes as shown in Figs. 50–51 .

Specimens examined. CHINA: Yunnan: Xishuangbanna , 550 m, 1959 . VI. 27, Zhen-Fu Li (1♂, IZCAS), 620–650 m, 1959 . V. 5, Zhen-Fu Li (1♀, IZCAS), 650 m, 1957 . III. 18, Shu-Yong Wang (5♂ 7♀, IZCAS), 650 m, 1957 . III. 20, Fu-Ji Pu (1♀, IZCAS), 650 m, 1957 . III. 20, Ling-Chao Zang (1♂ 3♀, IZCAS), 650 m, 1958 . IV. 16, Shu-Yong Wang (1♂, IZCAS), 650 m, 1958 . IV. 9, Chun-Pei Hong (1♂, IZCAS), 810 m, 1957 . III. 31, Shu-Yong Wang (1♂, IZCAS), 850 m, 1957 . VIII. 23, Shu-Yong Wang (1♂, IZCAS), 850 m, 1957 . III. 28, Ling-Chao Zang (1♀, IZCAS); Yiwu , 650 m, 1959 . VII. 22, Zhen-Fu Li (1♀, IZCAS).

Distribution. China (Yunnan, Taiwan, Hong Kong); Thailand, Sumatra, Celebes, Burma, India, Philippines, New Guinea ( Yano, 1978).

Remarks. This species is very close to S. senex but can be recognized easily by the twisted basitarsus of the foreleg in the male, which is typical and unique for S. plumbella . However, the fore basitarsus is normal in females, which leads to confusion between the female of S. plumbella and the female of S. senex .

Yano (1968) used the second tarsus and hind tibia as the distinguishing characters for these two species, they seemed to be not useful ( Yano, 1978). Steyskal (1980) tried to separate them by the external character of wing color in his key, but the wing color is variable ( Beaver et al., 1977). After examining 25 specimens (11 males, 14 females), we found the following two diagnostic characters to be reliable and convenient to use: 1) the frons of S. plumbella is dark brown except for yellow anterior margin between antennae, while the frons of S. senex is lighter, yellowish brown; 2) the antennal scape is dark brown, concolorous with other antennal segments in S. plumbella ( Fig. 45 ), while the antennal scape of S. senex is yellow, lighter than the other two segments ( Fig. 54 ).

Figures

FIGURES 41 – 51. Sepedon plumbella Wiedemann. 41. Male habitus, lateral view. 42. Female habitus, lateral view. 43. Frons, frontal view. 44. Foreleg, lateral view (showing twisted basitarsus). 45. Head, lateral view. 46. Male Sternum 5 and terminalia, ventral view. 47. Male postabdomen (cochleate vesicle inside), caudal view. 48. Male terminalia, lateral view. 49. Hypandrium (left part), lateral view. 50. Aedeagus and apodemes, lateral view. 51. Aedeagus and apodemes, ventral view.

FIGURES 52 – 60. Sepedon senex Wiedemann. 52. Female habitus, lateral view. 53. Frons, frontal view. 54. Head, lateral view. 55. Sternum 5. 56. Male postabdomen (cochleate vesicle inside), caudal view. 57. Male postabdomen (cochleate vesicle inside), lateral view. 58. Hypandrium (left part), lateral view. 59. Aedeagus and apodemes, lateral view. 60. Aedeagus and apodemes, ventral view.