Oxycera signata Brunetti, 1920

Yang, Zaihua, Wei, Lianmeng & Yang, Maofa, 2009, Two new species of Oxycera and description of the female of O. signata Brunetti from China (Diptera, Stratiomyidae), Zootaxa 2299, pp. 19-28 : 25-27

Oxycera signata Brunetti, 1920

( Figs. 18–27 )

Oxycera signata Brunetti, 1920: 54 . Type locality: India.

Diagnosis. Moderately large species with long paired medial longitudinal yellow vittae on scutum and contrasting yellow pattern on abdomen. Yellow scutellar spines slender and almost horizontal, subscutellum not protrudingg posteriorly. Vein R4 short but present, female tergite 3 with transverse row of spots, male aedeagal complex bipartite.

Description. Male body length 6.0 mm, wing length 5.0–5.5 mm.

Head transversely elliptical in frontal view, shining black, with black hairs; nearly equal width of thorax, 1.2 times broader than high in frontal view and nearly 1.1 times high as long as in profile (without antennae); vertex and ocellar tubercle black, with black hairs; eyes contiguous, dark brown, with dense black hairs. Antenna ( Fig. 22 ) with scape and pedicel dark, apical flagellomere with short black hairs; length of scape nearly equal to that of pedicel; flagellum black, basal 4 flagellomeres forming an elongate-oval complex, with whitish row of sensillae along distal margin of each flagellomere. Arista black, equal to remain of antenna. Frons and face flat, shining black, nearly bare, each side of face with a white vitta along eyes, consisting of white pubescence and hairs ( Fig. 23 ). Similar white vitta on each side of lower half of occiput. Proboscis pale yellow, with yellow hairs. Thorax mostly shining black, but with following yellow parts: postpronotal lobe and postalar callus; pair of longitudinal vittae being interrupted at the suture and not quite reaching anterior and hind margin of scutum but nearly connected with yellow postalar calli ( Fig. 18 ); side of scutum with broad vittae from postpronotal lobe to transverse suture; upper margin of pleura with distinct yellow vitta from postpronotal lobe to wing base ( Fig. 20 ); scutellum mostly yellow, with black posterior margin and a pair of brownish yellow spines. Hairs on thorax pale, but more brownish in front of scutellum and along posterior margin of scutellum. Wings pale brownish, hyaline, veins and stigma brownish yellow. Legs yellow but basal 2/3 of femora brown to black and basal half of fore tibia brownish yellow, apical half dark brown; mid tibia brownish yellow; basal and apical parts of hind tibia brownish yellow, middle blackish; fore tarsi black, mid and hind tarsi with bases of tarsomeres 1–2 brownish yellow, hind 1–2 tarsomeres dark to black. Halter yellow. Abdomen slightly broader than thorax, with following yellow parts on dorsum ( Fig.18 ): tergite 1 with a narrow transverse yellow fascia at base; tergite 2 with narrow yellow lateral margin; tergite 3 with a pair of large angular yellow spot on each side-margin reaching from anterior nearly to posterior margin; tergite 4 with a pair of spots on each side which is smaller than that of tergite 3; tergite 5 with a yellow apical spot; venter wholly black. Male genitalia ( Figs. 25–27 ) small; aedeagal complex bipartite, without median tube ( Fig. 26 ).

Female ( Figs. 19, 21 ). Body length 5.5–6.0 mm, wings length 5.0 mm. Similar to male except as follows: Eyes widely separated, with relatively broad postocular band; frons with a pair of yellow longitudinal vittae connecting with white vittae on face ( Fig. 24 ); antenna mostly brownish yellow; scutum with a pair of longitudinal vittae which are interrupted at suture, reaching anterior or hind margin of scutum and connected with yellow postalar calli ( Fig. 19 ); color of legs slightly darker than in male; abdominal dorsum with a subquadrate yellow spot in tergite 1 and a pair circular spots in middle of tergite 3; yellow lateral margin on tergite 2 broader than in male ( Fig. 19 ).

Specimens examined. 13, 3 ƤƤ, Guizhou Province, Huaxi, 1100m, 0 5 May 2008, Z.H. Yang leg. Distribution. China (Guizhou); India.

Remarks. The male of this species may be distinguished by dense hairs on the eyes, and a yellow pattern on thorax and abdomen. The female with a unique colour pattern on tergite 3 is described here for the first time. R. Rozkosny (pers. comm., 25 May 2009) compared the re-description of the male with the male holotype of O. signata Brunetti which is preserved in The Natural History Museum, London, and stated that the male specimen collected in China is conspecific with the holotype originating from India without any doubts. The holotype is labelled as follows: / Oxycera signata 3 Brun. Type / Holotype Oxycera signata Brunetti det. J. E. Chainey 1982 + Holotype (round label with red margin)/ Pres. By Agric. Inst., Pussa 1921- 427/ 3 Type H.T. (round label with red margin).

Figures

FIGURES 18 – 24. Oxycera signata Brunetti, morphological features. 18, male dorsal view; 19, female dorsal view; 20, male lateral view; 21, female lateral view; 22, male antenna; 23, male head, frontal view; 24, male head, frontal view.

FIGURES 25 – 27. Oxycera signata Brunetti, 1920, male terminalia. 25, tergites 9 – 10 and cerci, dorsal view; 26, aedeagal complex, dorsal view; 27, genital capsule, dorsal view.