Ommatius (Pygommatius) litoreus, Scarbrough & Marascia, 2003

Scarbrough, Aubrey G. & Marascia, Claudio G., 2003, Revision of Ommatius Wiedemann (Diptera: Asilidae). IV. Pygommatius subgen. nov. with twenty-five Afrotropical species, Zootaxa 228 (1), pp. 1-94 : 41-43

Ommatius (Pygommatius) litoreus , sp. n.

Figs. 13 , 26 , 35 , 43 , 152­159

Male. Length, body 10­11.0 mm; wing 7.0­ 7.5 mm. Black. Head: Yellow to gray tomentose with mostly yellow to white setae. Face with 6 thin, brown bristles and 4 pencil­like yellow bristles; several, thinner, yellow bristles ventrally; sparse yellow setae present dorsally; FHWR 1.0:7.1­1.0:7.5. Proboscis and palpus with very narrow base yellow. Frons brown setose. Antenna brown; pedicel bead­like, as long as but much wider than flagellum. Frons yellow to brown­yellow tomentose. Ocellar tubercle with longest seta subequal to 3 antennal segments combined. Occiput with 3­5 brown bristles, longest with apex third distance toward ocellar tubercle.

Thorax: Mesonotum with mostly brown tomentum, postalar callus and prescutellum yellowish, narrow sides yellowish­gray; setae sparse, short, mostly brown; 3­4 dorsocentral and 4 lateral bristles present. Scutellum dorsally brown tomentose, apically yellow; sparse, thin, yellow setae and 2 brown marginal bristles present. Pleuron mostly black, narrow posterior below halter yellow; tomentum yellowish­gray tomentose; yellow setose; thin, yellow anepimeral bristle present. Halter yellow to reddish­yellow.

Wing ( Figs. 13 ): Microtrichia dense apically, extending as narrow lines in anterior cells and along posterior margin. Cell r 4 with veins slightly diverging apically. Apex of cell m 3 perpendicular to wing axis, slightly curved, just beyond r­m.

Leg: Fore and hind coxae yellow, middle coxae brown; tomentum gray, setae and bristles mostly yellow, none unusually thick; fore coxa apically with numerous, short, brown setae. Trochanters mostly yellow, at least ventrally, narrow margins brown; hind trochanter often brown posteriorly with a short yellow bristle. Fore and middle femora yellow, narrow apices often brown, hind femur mostly yellow, apical half to slightly less brown. Fore femur ( Fig. 26 ) basally wide with 4­5 thick, unusually long, yellow, ventral bristles. Middle femur with brown bristles anteriorly; anteroventral bristles absent, 3­4 short yellow setae present; 4 thick, yellow bristles and a long row of short, comb­like, yellow bristles present posteroventrally. Hind femur ( Fig. 35 ) widest at basal third, a weak ventrobasal concavity present; 1 unusually long, brown, anteroventral bristle present on apical third; 3­ 5 short, brown, posteroventral bristles with round apices present basally, and a row of several setae and bristles beyond basal group of bristles, the basal ones shortest, each being longer and thicker, apical bristle unusually long and separated from row by wide space; HFWLR 1.0:5.4­1.0:5.8. Tibiae entirely to mostly yellow; hind tibia ( Fig. 43 ) with apical third brown, slightly swollen medially with numerous, yellow and brown setae on basal half, several long and bristly; preapically only slightly constricted; raised, black flange present apically, slightly concave on one side. Fore and middle tarsi with basal tarsomere mostly yellow, narrow apex brown, the former with 1­2 yellow bristles; basal tarsomere of hind tarsus light yellowish­brown basally.

Abdomen: Brown with apical margins of all tergites and basal 5 sternites, and narrow lateral margins and wide apical corners of most tergites yellow. Tergites mostly brown tomentose dorsally, sides and sternites gray to yellow; mostly short, brown setae present. Apical 6 tergites with 1­2 or more bristly setae apical margins; sternites 4 and 6 with erect, yellow bristles, those on 4 longest; sternite 5 with several, short, thick bristles in apical corner, most yellow, 3­5 usually brown, plus a few minute bristles posteriorly, peg­like. Sternites 7­8 brown setose; numerous brown bristles present along apical margin of sternite 8.

Terminalia ( Figs. 152­156 ): Epandrium 2 branched; dorsal branch narrowed apically, apex acute; ventral branch wide apically, with corners turned vertically. Gonocoxite with surface rugose, prominent flange present. Aedeagal sheath flat, expanded laterally, forming an oblique, oval, shield above distiphallus; surface with minute grooves. Hypandrium strongly produced, narrow ventrally, with strong angular apex; surface with minute grooves and ridges.

Female. Differs from male as follows: Length, body 9.0­ 11.3 mm; wing 7.4­8.5 mm. Head: FHWR 1.0:6.6­1.0:6.7. Proboscis with narrow base light brown to brown­yellow. Thorax: Anepimeral bristle thin, seta­like. Leg: Fore coxa with only yellow bristles and setae. Hind coxa, fore trochanter, and middle trochanter brown­yellow; hind trochanter brown. Femora normal, without unusually long, thick bristles ventrally. Middle femur basally with 3 long, thin, brown or yellow, anteroventral bristles; a row of 4­5 thin, long, usually brown, posteroventral bristles present; comb­like row of short, thin, yellow bristles absent. Hind femur normal, without a ventral constriction basally; 2 rows of 5­7 long, thin, mostly brown, bristles, in each ventral row; basal 3 posteroventral bristles third as long as hind femur; apical bristle in each ventral row not unusually long as in male; HFWLR 1.0:5.7­1.0:6.3. Hind tibia sometimes slightly swollen medially, otherwise normal. Abdomen: Most segments with apical margins yellow, sides of tergites narrowly yellow; all bristles along apical margin short, thin, seta­like. Sternites 4­6 without bristle patterns as in male. Tergitre 9 extremely narrow dorsomedially, membranous. Terminalia ( Figs. 157­ 159 ): Three spermathecae present; duct basal, slightly lateral.Sternite 8 with apical margin broadly rounded; a short, low median carina present medioapically.

SPECIMENS EXAMINED. Holotype ♂, allotype ♀, paratypes 2 ♂, KENYA: Kilifi Distr. / Mida Creek 8 mi S. / Gede. 201 20.I.1970 / M. E. Irwin and / E. S. Ross ( CASC) . Paratypes: KENYA: 1 ♀, Kilifi Distr. / Gede. alt. 100 ft. / 31.xii.1969 / M. E. Irwin and / E. S. Ross ( CASC) ; 4 ♂ [1 without terminalia], 6 ♀ [1 without terminalia], Diani Beach / vii.1951 / N. L. H. Krause / B. M. 1951­541 ( BMNH) ; 6 ♀, Diani Beach / viii.1951 / N. L. H. Krauss / B. M. 1951­541 ( BMNH) ; 1 ♀ [terminalia absent], Diani Beach / ix.1951 / N. L. H. Krauss / B. M. 1951­541 ( BMNH) ; 1 ♀, Mombasa / Diani Beach / 20.xii.1961 / J. Bowden ( BMNH) ; 2 ♀, Gedi N. R. / 7­8.xi.1973 / Michel Boulard ( MNHN) .

Distribution. A riverine species captured at low elevations from September to August in Kenya.

Etymology. Latin, litoreus , meaning shore or beach, referring to the site where specimens were collected.

Remarks. In addition to the characters in the key, O. litoreus is also distinguished by the presence of stout ventral bristles on the base of the fore femur ( Fig. 26 ) and the stout posteroventral bristles and numerous, short, comb­like bristles on the middle femur.

Figures

FIGURES 11­20. Right wing of male Ommatius (Pygommatius) spp. 11. O. imaginus, sp. n..; 12. O. limbus, sp. n..; 13. O. litoreus sp. n.; 14. O. lulua, sp. n.; 15. O. magnipes, sp. n.; 16. O. ornatipes Engel; 17. O. pectinus sp. n.; 18. O. porticus, sp. n.; 19. O. renudus, sp. n.; 20. O. strigiatus, sp. n.

FIGURES 21­28. Right wing of male Ommatius (Pygommatius) spp. 21. O. talus, sp. n.; 22. O. vultus, sp. n.; 23­28. Right fore femur of male Ommatius (Pygommatius) spp. showing arrangement of anteroventral bristles. 23. O. brevicornis Curran; 24. O. grossus, sp. n.; 25. O. limbus, sp. n.; 26. O. litoreus, sp. n.; 27. O. strigiatus, sp. n..; 28. O. vultus, sp. n.

FIGURES 29­38. Male Ommatius (Pygommatius) spp. 29. O. jaculator Walker, middle femur. 30­ 38. Hind femur, 30. O. brevicornis Curran, anterior view; 31. O. comosus, sp. n., anterior view; 32. O. dasypogon Oldroyd, anterior view; 33. O. jaculator Walker, anterior view; 34. O. limbus, sp. n., with coxa, anterior view; 35. O. litoreus, sp. n., anterior view; 36. O. neglectus Bromley, anterior view; 37. O. strigiatus, sp. n., posterior view; 38. O. vultus, sp. n., posterior view.

FIGURES 39­48. Left hind tibia of male Ommatius (Pygommatius) spp. 39. O. comosus, sp. n.; 40. O. fluvius, sp. n.; 41. O. imaginus, sp. n.; 42. O. limbus, sp. n., anterior; 43. O. litoreus, sp. n.; 44. O. neglectus Bromley; 45. O. porticus, sp. n.; 46. O. renudus, sp. n.; 47. O. strigiatus, sp. n.; 48. O. vultus, sp. n., inner surface.

FIGURES 152­159. Male terminalia of Ommatius litoreus sp. n. 152­154. Lateral, dorsal and ventral views; 155. Gonostylus; 156. Aedeagus, lateral view. Female terminalia. 157. Spermatheca; 158. Genital fork; 159. Sternite 8, ventral view.