Ommatius riali Vieira, Castro & Bravo, 2005

Vieira, Rodrigo, Castro, Ivan & Bravo, Freddy, 2005, A new species of Ommatius Wiedemann (Diptera: Asilidae) from Brazil, Zootaxa 1017 (1), pp. 19-24 : 21-23

Ommatius riali Vieira, Castro & Bravo , sp. nov. ( Figs. 1–7 )

Type material. Holotype male: Brazil, Bahia, municipality of Cachoeira , 20.VII.2004, Rodrigo Vieira col. ( CUFS).

Etymology: The name riali is dedicated to Mr. Rial, owner of the farm where the specimen here described was collected.

Male. Length: body, 11.7 mm; wing, 8.0 mm. Body black. Face and front with gray vestiture; mystax composed of face with six brown bristles; FHWR (face­to­head ratio) 1/ 7.0. Palpus yellowish to brown setose. FWLR (width­to­length ratio of flagellum) 1/4.0. Occiput with six dark brown postocular bristles on each side of head; lower occipital bristles white.

Scutum with four long dorsocentral bristles; transverse suture with gray and golden pile; one notopleuron bristle; one postalar bristle; anepimeral bristle absent; katepisternum with yellow bristles; anepisternum with white bristles. Scutellum with two weak marginal bristles.

Pleuron mostly grayish tomentose; wing with costal margin dilated and abundant microtrichia on the cells r1, r2+3, r4, r5, m1, m2 and m3. Wing slightly yellowish posteriorly; halteres dark yellow. Legs mostly yellow; fore and mid femora with apical third brownish to black. Coxae and trochanter blackish. Hind femora with apical two­thirds black, with seven brown anteroventral bristles. Mid femora with a long, thin, pale, preapical, dorsoposterior seta; basal half of mid femora with three anteroventral bristles. HFWLR (width­to­length of hind femur) 1/5.6. Hind tibiae with a spurlike apical bristle ( Fig. 5 ) and half its length black. Tarsomeres of hind tarsus wholly black; basal tarsomeres of fore and middle tarsus partly yellowish; pulvilli yellowish.

Abdomen dorsally with dark­brown tomentum; sides of tergites and sternites with pale yellowish vestiture.

Terminalia blackish. Epandrium with two long bristles; with a long inner projection in ventral view ( Fig. 7 ); ventral margin with small anterior lobe in lateral view ( Fig. 6 ). Width of the median region of epandrium, in dorsal view, three times apical width ( Fig. 4 ). Hypandrium suboval ( Fig. 7 ). Gonostylus narrow in lateral view with angular external margin ( Fig. 3 ). Aedeagus with apex strongly curved downward ( Fig. 1 ). Anterior portion of aedeagal apodeme slightly curved upward ( Fig. 1 ). Aedeagal sheath resembling trapezium ( Fig. 1 ); anterior margin U­shape ( Fig. 2 ) in dorsal view.

Comments. The new species O. riali is similar to O. costatus Rondani, 1850 and O. spatulatus Curran, 1928 . O. riali sp. nov. presents scutellar and dorsocentral bristles in the thorax, while in O. spatulatus these bristles are absent. Futhermore, the abdomen of O. spatulatus is very spatulate while that the abdomen of O.riali is slightly spatulate.

O. riali sp. nov. differs from O. costatus because the new species presents a long digitiform apical projection in the inner margin of the epandrium, while O. costatus this projection is short.

Figures

FIGURES 1–7. Ommatius riali Vieira, Castro & Bravo sp. nov. holotype male. 1. Aedeagus, lateral view. 2. Aedeagus, dorsal view. 3. Right gonostylus. 4. Male terminalia, dorsal view. 5. Right hind tibia with a spurlike bristle. 6. Male terminalia, lateral view. 7. Male terminalia, ventral view.