Systropus brochus, Cui, Weina & Yang, Ding, 2010

Cui, Weina & Yang, Ding, 2010, Two new species and two new synonyms of Systropus Wiedemann, 1820 from Palaearctic China (Diptera: Bombyliidae), Zootaxa 2619, pp. 14-26 : 16

Systropus brochus sp. nov.

( Figs. 1–7 , 34–36 )

Diagnosis. Mesoscutum with three pale yellow lateral spots. Scutellum black with yellow posterior border bearing pale pile. Metasternum black except anterior part with a V-shaped yellow pattern. Hind coxa black, trochanter brown, femur brownish yellow, tibia black except apical 1/5 yellow, tarsus brown to dark brown except first tarsomere yellow.

Description. Male. Body length 20 mm, wing length 14 mm.

Head black except lower frons, face and gena yellowish, ocellar tubercle red brown. Setulae on head yellowish, except lower frons, face and gena with short silvery white pile; upper occiput with black setulae along eye margin. Antennal scape and pedicel yellow, with short yellowish brown setulae; first flagellomere black, flat and bare. Antennal ratio 2.7: 1: 2. Proboscis black except basal ventral portion mostly yellowish brown, bare; palpus brown with very short pale setulae.

Thorax black with yellow spots. Setulae on thorax pale and dark brown; yellow areas with pale setulae. Propleuron pale yellow. Postpronotal lobe pale yellow. Mesoscutum with three pale yellow lateral spots, anterolateral spot transverse and subtriangular, midlateral spot onion-shaped, anterolateral spot connected with midlateral spot by wide yellow band. Posterolateral spot triangular, connected with midlateral spot by narrow yellowish brown line. Anepisternum black. Postalar callus yellow. Scutellum black with yellow posterior border bearing pale pile. Anepimeron with anterior portion dark brown and posterior portion gray, posterior margin with pale pile. Metasternum black except anterior part with V-shaped yellow pattern.

Fore leg yellow except second to fifth tarsomeres yellowish brown; 3 dark brown dorsal setulae present at tip of fifth tarsomere. Mid leg yellow except posterior portion of coxa black. Hind coxa black; trochanter brown; femur brownish yellow; tibia black except apical 1/5 yellow; tarsus brown to dark brown except first tarsomere yellow. Claws shining black; pulvilli yellow. Setulae on legs mostly short and recumbent, those on black area black while those on yellow area yellowish brown. Hind tibia with three rows of black spine-like setae (7 ad, 7 av and 3 pv). Mid and hind tarsi with black spine-like ventral setae.

Wing with smoky infuscation; veins brownish. Halter stem yellowish brown; knob pale yellow.

Abdomen yellow except tergite 1 black with anterior margin wider than scutellum; tergites 2–5 with dark brown mid-longitudinal stripes; tergite 6 to hypopygium dark brown. Petiolus formed from segments 2–4 and anterior part of segment 5; segments 5–8 inflated, ovate. Setulae on abdomen black and pale; tergites with dense recumbent black setulae, sternites with pale setulae.

Male genitalia ( Figs. 1–7 ). Epandrium ( Figs. 1–2 ) as long as wide, rectangular; surstylus blackened at dorsal apical portion and pointed in posterior view; cercus in posterior view rather subtriangular and with large and wide blackened tubercle situated along inner margin of cercus. Sternite 10 ( Fig. 2 ) U-shaped and wide in posterior view. Gonocoxite ( Figs. 3–5 ) longer than wide, with large V-shaped basal incision and small V-shaped apical incision in ventral view, with numerous black bristle-like setae; gonostylus ( Figs. 3–5 ) longer than wide with acute tip, and narrowed from base to tip in lateral view. Midposterior part of dorsal band with pair of large circular convexities in dorsal view; median epiphallic lobe log-like; lateral epiphallic lobe widest before apex, with short blackened tooth-like projections near posterior inner angle and posterior outer angle.

Female. Unknown.

Type material. Holotype male, CHINA: Shaanxi, Zhouzhi, Qinling Mountains Botanical Garden (34° 10’ N; 108° 12’ E), 17. VII. 2006, Yajun Zhu.

Distribution. China (Shaanxi).

Etymology. The specific name refers to the lateral epiphallic lobe with short blackened tooth-like projections near the posterior inner angle and posterior outer angle in dorsal view.

Remarks. The new species is somewhat similar to S. denticulatus ( Du & Yang, 2009) from China (Yunnan) in having similar spots on the mesoscutum, but it can be separated from the latter by the antennal ratio 2.7: 1: 2; the lateral epiphallic lobe widest before the apex and with a short blackened tooth-like projection near the posterior inner angle and posterior outer angle. In S. denticulatus , the antennal ratio is 2: 1: 1.75; the lateral epiphallic lobe is not widest before the apex, with serrate tooth-like projections along the entire apical margin ( Du & Yang 2009).

Figures

FIGURES 1 – 7. Systropus brochus sp. nov. 1. Male genitalia, posterior view; 2. epandrium, cercus and sternite 10, ventral view; 3 – 5. gonocoxite and gonostylus, ventral, dorsal and lateral views; 6 – 7. phallus, dorsal and lateral views.

FIGURES 34 – 36. Systropus brochus sp. nov. (male). 34. Body, lateral view; 35. mesoscutum and scutellum, dorsal view; 36. metasternum, posteroventral view.