DASTPOGONINAB 



ROBBER FLIES OF THE WORLD 



121 



Third antennal segment slender or at most slightly wider 

 than the second segment 47 



47. Anal cell closed with a rather long stalk 48 



Anal cell open 49 



48. The second vein and anterior branch of third vein end close 



together, far above wing apex ; proboscis longer than face ; 

 third antennal segment never greatly enlarged. 



Bathypogon Loew 



The anterior branch of third vein ends near apes of wing; 



third antennal segment greatly swollen ; proboscis not 



longer than face Pbitchardia Stuardo 



49. The anterior branch of the third vein branches at the end of 



the discal cell Zabrotica Hull 



The anterior branch of the third vein branches beyond the 

 end of the discal cell . . . Creolestes, new subgenus 



50. Eye reduced in extent ; front and face strongly produced ; 



face with a deep crease situated shortly below the frontal 

 antennal process; face densely beset with long, stiff pile. 

 Area below the eye (gena) and the occiput unusually 

 extensive owing to the reduction of the eye. Antenna 

 much longer than the head, slender throughout. Anterior 

 branch of third longitudinal vein with a spur near the 



base Htstrichopogon Hermann 



Eye normal in extent. Face and antenna not so constructed. 

 Appendicular vein absent 51 



51. Small flies with aberrant antenna and short, convex face 



bearing loose, quite long pile; bristles absent. Third an- 

 tennal segment wide apically with 2 prominent micro- 

 segments of the same width and each as wide as high. 



PSEUDOHOLOPOGON Stl'Obl 



Flies without such antennal characteristics .... 52 



52. Antenna elongate, usually longer than the head. Third 



segment long and distinctly wider than the second segment 

 throughout most of its length. Occiput prominent and 

 tumid dorsally. Vertex scarcely excavated or plane with 



eye margin 53 



Antenna usually not longer than head, or if of greater 

 length the third segment never wider than the 

 second 56 



53. Face with no pile and bristles reduced to a single row or 



small cluster above epistoma 54 



Face with abundant pile or bristles 55 



54. Antenna more than twice the length of head. Pronotum 



unusually long ; transverse mesonotal suture not evident. 

 Face very high, the front quite short with antenna at- 

 tached near the upper plane of the head. Medium-size 

 and small flies. Bicolored species, black with red thorax 

 as in the bibionid Plecia Wiedemann. Pile and bristles 

 reduced but epistomal bristles stout and situated in 1 

 row. Apex of proboscis simple . . Macbocolus Engel 

 Antenna not more than 1% times the length of head. Not 

 so colored. Medium size flies, orange brown in color with 

 a small cluster of supraepistomal bristles. Apex of pro- 

 boscis fissiform Neodioctria Ricardo 



55. Face distinctly convex and densely pilose over the whole 



surface. Mesonotum, whole of scutellar disc and margin, 

 and abdomen densely, long, fine pilose; comparatively 

 small flies. Fourth posterior cell usually considerably 



narrowed Spanurus Loew 



Face plane, or gibbous below ; bare on the upper half. 

 Lower part of face with pile or weak bristles. Com- 

 paratively short pilose, relatively bare and usually 

 opaque pollinose flies ; small to moderate in size . . 55a 

 55a. Third antennal segment long and rather wide, tapered 

 only near immediate base and apex. Palpus small, 

 slender, rather bare. Scutellum with 1 or 2 pairs of 

 bristles and sometimes with 1 or 2 bristly hairs as well. 

 Fourth posterior cell generally narrowed to half its 



maximal width Scylaticus Loew 



Third antennal segment long but slender, not wider than 

 the second segment. Palpus quite large, long, swollen 

 with long, dense bristles. Whole posterior margin of 

 scutellum with an extensive, dense fringe of long bristles 



and bristly hairs. Fourth posterior cell open in its maxi- 

 mum width Pyncnomerinx, new genus 



56. Small, dark flies with quite short, convex face scarcely vis- 



ible beyond the eye margin in profile and distinguished by 

 dense, fine, white pile of the face, thorax, sides of abdomen 

 and the sternites. Antenna slender, the third segment and 



its microsegment attenuate 57 



Flies of loose pile with bristles intermixed, or only with 

 bristles; face more prominently developed .... 58 



57. Face one-third of the head width and pile of front and occi- 



put exceptionally long Eriopogon Loew 



Face one-fourth the head width or less. Pile of front and 

 occiput not unusually long .... Jothopogon Becker 



58. Third antennal segment strongly dilated distally or through- 



out the base or middle portion 59 



Third antennal segment without dilation ; usually not wider 

 than the second segment 61 



59. Third antennal segment dilated strongly on the distal half ; 



face very short beneath antenna. Proboscis distinctly ex- 

 tended beyond the face 60 



Third antennal segment strongly dilated through the middle. 

 Face immediately produced beneath the antenna. Two 

 microsegments and a spine present. Proboscis no longer 

 than the face Cycloscerus Bezzi 



60. Occiput with numerous, stout bristles, strongly proclinate 



dorsally Hypenetes Loew 



Occiput with only fine, stiff hairs. 



Tillobroma, new subgenus 



61. Third antennal segment very slender and elongate; its apex 



clublike and bearing a subapical spine; male anterior 

 femur at base with large, hamate process ; densely long, 

 fine, pilose flies with very convex face, dense, mesonotal 

 mane and laterally compressed abdomen . Oldboydia Hull 

 Third antennal segment never exceptionally slender ; and 

 also with its apex clublike and bearing a subapical 

 spine 62 



62. Eye high and short, the face short but convex; the entire 



head densely, long, fine, pilose. Supraepistomal region 

 with bristles. Third antennal microsegment with a plu- 

 mose tuft of hairs Crobtlocerus Loew 



Third antennal microsegment without tuft 63 



63. An additional crossvein present regularly, extending from 



basal part of third vein to the fourth vein ; as a result, 2 

 crossveins enter the discal cell in front. 



Grypoctonus Speiser 

 Only the normal, anterior crossvein present .... 64 



64. Face quite plane from antenna to epistoma. Face with a 



single row of short, epistomal bristles and a small patch 

 of medial, weak bristles on the lower part of face. Occip- 

 ital bristles proclinate, including the lower bristles. 



Harpagobroma, new genus 

 Face not plane 65 



65. Flies in which the third antennal segment is elongate and 



slender, attenuate at apex and bears 1 or usually 2 slender, 

 attenuate microsegments ; flies frequently of dense, long 



pile 66 



Third antennal segment stout, at most slightly narrowed 

 at the immediate apex ; microsegment single, short, stout, 

 often small ; flies sometimes pollinose, of rather small size 

 and reduced pile but abundant bristles 77 



66. Face but little developed, but distinctly plane, rising a little 



immediately below the antenna and plane to oral margin, 

 the whole of it covered with distinctly bristly pile of no 

 great length, and no stout bristles below at the oral mar- 

 gin. Apex of midtibia with at most 1 somewhat stiffer 

 bristle. Hind tibia conspicuously thickened throughout 

 its length. Anal cell quite widely open. Mesonotum 

 arched and compressed. Scutellar margin and disc with 

 abundant, coarse, or slightly bristly pile. Anterior cross- 

 vein enters the discal cell at the middle; the third vein 

 forks opposite the end of the discal cell. Metallic 



flies Sintoria, new genus 



Not such flies, the face either extensively produced and gib- 

 bous, with long, fine, dense pile or if the face is short, 



