DASTPOGONINAB 



ROBBER FLIES OF THE WORLD 



107 



from the base bearing an oblique, long microsegment 

 which is more than a third the length of the third seg- 

 ment and carries a stout apical spine. 



Head, anterior aspect : The face below antenna little 

 more than one-eighth the head width and divergent 

 below. Face pubescent, the lower anterior epistomal 

 margin with a dense mat of stout bristles, rather short 

 and not longer than the proboscis. There are some 6 

 or more pairs. Sides of epistoma with 4 slender, long 

 hairs. Front strongly divergent and continued up to 

 the top of the vertex. The front has fine, long, scattered 

 pile. The ocellarium is low with 4 or 5 pairs of stiff, 

 short, curled hairs. Eye facets unusually strongly en- 

 la iged centrally. 



Thorax : The thorax is everywhere pollinose. Pile of 

 mesonotum short, fine, scanty, setate and subappressed. 

 Acrostical elements absent or poorly differentiated. 

 Dorsocentral elements differentiated only posteriorly 

 and consist of a few, fine rather short, stiff hairs. Hu- 

 merus pilose; lateral bristles long and stout, 1 noto- 

 pleural, 1 supraalar, and 1 postalar; 3 pairs of scutellar 

 marginal bristles. Scutellum flat with abrupt, polli- 

 nose rim and pile only marginally. Propleuron with 

 abundant, fine pile; mesopleuron with a few, fine hairs 

 along the posterior border only. Sternopleuron with 2 

 or 3 hairs; hypopleuron without pile or bristles; meta- 

 pleuron with a vertical band in 1 row of 9 quite long, 

 slender, fanlike bristles. Metanotal slopes pubes- 

 cent only; lateral metasternum without pile. Post- 

 metacoxal area membranous, though slightly nar- 

 rowed. 



Legs: The hind femur is slender towards the base; 

 the anterior four femora are a little thickened. The 

 hind femur bears 1 dorsomedial, 1 apical and 1 sub- 

 apical bristle, 4 lateral, and 3 exceptionally long ventral 

 bristles; hind tibia with 3 long, dorsal, 1 dorsolateral 

 at the base, 1 lateral in the middle, and 2 ventral 

 bristles. Apex with 6 bristles. These legs bear dense, 

 appressed, setate pile. All tarsi end in slender pulvilli, 

 a long empodium, and sharp, slender claws. 



Wings: The wings are as in other members of the 

 group; the second submarginal cell is strongly ex- 

 panded anteriorly at the base; the anterior branch of 

 the third vein ends at wing apex. All posterior cells 

 are widely open. Anal cell closed. The anterior cross- 

 vein enters the discal cell near the base. The second 

 basal cell ends in two veins which are fused beyond. 

 Alula narrow; ambient vein complete. 



Abdomen: The abdomen is basally as wide as the 

 mesonotum and a little flattened basally ; it is tapered 

 posteriorly and subcylindrical with the sides rolled. 

 Pile abundant, setate, erect or suberect; bristles re- 

 stricted to the first tergite where they are long but ex- 

 tremely weak. There are 8 tergites well developed in 

 the female. Female terminalia with about 4 pairs of 

 blunt spines on the acanthophorites. Basal plate mod- 

 erately produced posteriorly. 



Subgenus Echinopogon Bezzi 



Figures 452, 931, 940 



Echinopogon Bezzi, Ann. Mus. Nat. Hungarici, vol. 8, p. 131, 

 1910. Type of genus : Dasypogon albofasciatus Meigen, 

 1820, by original designation. 



Quite small flies comparatively slender and at least in 

 part pollinose. They are very closely related to Sticho- 

 fogon Loew, and principally distinguished by the loose 

 character of the stout bristles which compose the 

 mystax, in contrast to the bridgelike or tectiform ar- 

 rangement of these bristles in Stichopogon and its other 

 subgenera. The ocellar bristles are weak. The face is 

 bare above the epistoma, the palpus bare except at base, 

 and the lower posterior part of the eye is exceptionally 

 i-ecessive, leaving the occiput greatly exposed. Anten- 

 nal microsegment inclined downward. Length 7 or 

 8 mm. 



Head, lateral aspect: The face in profile very slightly 

 produced on the upper half, below forming a small tri- 

 angle prominent because of recession of the eye. The 

 eyes are unusually long and strongly convex anteriorly. 

 Occiput exceptionally thick at the middle and below 

 and on the dorsal half gradually sloping down to the 

 eye level at the vertex. Occipital pile nearly absent 

 dorsally, moderately abundant in the middle, where it is 

 fine and erect and quite dense and directed downward 

 on the lower half. Bristles restricted to the upper sev- 

 enth of the head, where there are 9 stout, rather short 

 bristles. Proboscis small and short, slightly swollen 

 towards the base, the apex obtuse with a few, stiff hairs 

 and the base below with numerous, fine, long hairs. 

 Palpus quite slender, composed of two segments. An- 

 tenna attached at the middle of the head, slender and 

 moderately long, the first segment quite short, as long 

 as high, the second segment swollen apically, the third 

 more narrow than the apex of the second and very 

 slightly narrowed towards the apex and bearing an at- 

 tenuate, obliquely held microsegment which carries an 

 apical spur. The third segment is nearly twice as long 

 as the combined length of the first two segments; the 

 microsegment is as long as the second segment. 



Head, anterior aspect : Face below antenna about one- 

 sixth of head width and strongly divergent below. Sub- 

 epistomal region moderately large but nearly horizon- 

 tal, plane and bare. Face pubescent, bearing a number 

 of exceptionally stout, moderately long bristles in sev- 

 eral rows anteriorly above the epistomal margin. Side 

 margins with weaker bristles. The front as is char- 

 acteristic in the group is widely and strikingly ex- 

 panded to the vertex where it is half the head width. 

 Front pollinose with numerous, fine, erect hairs. Ver- 

 tex scarcely excavated; ocellarium large and low and 

 bearing a few, weak hairs. The occipital bristles form 

 a stout row behind the vertex. Eye facets greatly en- 

 larged anteriorly. 



Thorax : The thorax is everywhere pollinose. Pile of 

 mesonotum quite short and fine and suberect; no clearly 

 differentiated acrostical bristles present. Dorsocentral 

 elements are present as long, fine slender hairs pos- 



