DASYPOGONINAE 



ROBBER FLIES OF THE WORLD 



61 



below. The proboscis is comparatively high, some- 

 what compressed laterally, produced only a little be- 

 yond the face and with a low dorsal keel; the lower 

 surface, except at the base, is plane, and dorsally the 

 apex is strongly arched; the apex bears numerous, stiff, 

 bristly hairs, the basal ventral portion has a few long, 

 fine hairs. Palpus of two segments, but the basal seg- 

 ment minute, hidden behind the leaf-thin posterior 

 plate of the head, and the long cylindrical second seg- 

 ment is bent forward beneath the edge of the plate at 

 a right angle; it bears numerous fine hairs and 2 or 3 

 slender bristles at the apex. The antenna is attached 

 a little above the middle of the head; the first segment 

 is quite short, the second short and beadlike. On the 

 first is a long bristle and some fine hairs ; second with 

 only fine setae; third segment minute, smaller and more 

 narrow than the second segment, with a long fine style 

 three times the combined length of all segments. 



Head, anterior aspect : The head is very wide, the eyes 

 greatly flattened, the mediocentral facets greatly en- 

 larged. The face below the antenna approximately one- 

 fifth the head width and divergent below with deep 

 creases between cheek and eye. The face is coarsely 

 pubescent and bears 2 groups of very slender, numerous 

 bristles or bristly hairs ; the upper group begins near the 

 bottom of the face and broadly covers the middle of the 

 face, its elements curved upwards. The lower group 

 occupies the ventral, retreating third of the face, its 

 elements are longer and curved downward, but not 

 stouter. The front and vertex are slightly widened; 

 anteriorly the front is sunken so that the antenna is set 

 in a transverse depression. The whole front is vertical, 

 pubescent, without pile. The ocellarium is large but low 

 with large ocelli, the whole structure is visible in profile, 

 facing anteriorly and has two slender bristles behind the 

 ocelli and considerable stiff pile along the transverse 

 posterior margin of the vertex. Laterally the eyes rise 

 considerably above the vertex and from a dorsal aspect 

 the vertex is excavated and flared outward. 



Thorax : The mesonotum is quite high, almost as high 

 as long, and strongly arched both anteriorly and pos- 

 teriorly. It is coarsely pubescent laterally and an- 

 teriorly but with large medial and submedial bare 

 stripes. The pile is scanty, fine, and suberect. The 

 acrostical bristles are well developed and isolated an- 

 teriorly. The dorsocentral bristles are isolated only 

 near the middle of the mesonotum, but well before the 

 transverse suture, which is strongly oblique. Generally 

 there is a large patch of long pile above the scutellum. 

 Humerus pubescent only. There are no differentiated 

 bristles laterally on the mesonotum. The very thick, 

 convex scutellum has a row of long, stiff hairs on the 

 margin, and the surface is densely, coarsely pubescent. 

 Propleuron with scattered, long hairs which are rather 

 abundant. Whole of the mesopleuron, upper sterno- 

 pleuron, and posterior hypopleuron with numerous, 

 long, fine hairs. Metapleuron has a large, circular patch 

 of numerous, stiff, long hairs covering nearly the whole 

 of its surface. Metasternum pilose, postmetacoxal area 



membranous, the prosternum fused laterally and ven- 

 trally. The whole surface of the pleuron coarsely 

 m icr opubescent. 



Legs: All the femora are stout, a little swollen, the 

 hind pair rather strongly swollen on the distal half 

 and attenuate basally. The tibiae are stout and become 

 more stout and swollen distally. Hind legs consid- 

 erably longer than the others. Pile of the legs greatly 

 reduced basally on tibiae and femora, becoming some- 

 what more abundant, fine, setate and appressed dis- 

 tally. Bristles for the most part are weak, long, slen- 

 der, and sharp. The hind trochanters bear ventrally 

 at apex a cluster of 12 to 15 bristles. The hind femur 

 has 5 sharp, tuberculated, spinous bristles ventrolater- 

 ally, 2 others ventromedially, all of them on the distal 

 half; its tibia without bristles except at the apex. 

 Middle femur with a ventral double row of 12 to 14 

 long, slender bristles, a few of these elements being 

 stout, its tibia with 5 posterior and 5 postero ventral 

 bristles, all of them long and conspicuous and with 

 an anterior, anteroventral and ventral fringe of long 

 hairs. Apex of this tibia with a conspicuous, stubby, 

 ventral process carrying short, spinous bristles, its 

 basitarsus reduced in thickness, the next three seg- 

 ments with oblique, rather sharply pointed ventral 

 protuberances. Anterior femur and tibia with only 

 fringes of numerous long, bristly hairs and the apices 

 of this tibia unmodified. The anterior basitarsus, 

 however, has posteriorly a row of rather conspicuous 

 dense bristles throughout its length, but most numer- 

 ous basally, and mixed with long hair. Claws small 

 but sharp, the pulvilli and empodia well developed. 



Wings: The wings are broad, tinged darkly with 

 brown; all cells are widely open, except the anal cell, 

 which is closed with a long stalk. Second basal cell 

 ends in 2 veins. Alula nearly 4 times as long as wide, 

 the ambient vein ends at the anal cell. The anterior 

 crossvein enters the discal cell at the outer third. 



Abdomen: The abdomen is robust, but compara- 

 tively long, at the base not quite as wide as the mesono- 

 tum; the pile is very dense everywhere but short and 

 plushlike dorsally, increasing in length so that the 

 sides of the tergites are conspicuously fringed with 

 long, coarse hairs. Bristles absent on all segments. 

 Males with 7 tergites only. Male terminalia fully 

 rotate, the epandrium broadly and deeply but not 

 completely cleft; there is a considerable fused, basal 

 portion and the lateral arms are large, obtuse, mas- 

 sive, long, and conspicuous. The proctiger is small 

 and flat. The hypandrium is short, broad, with a 

 slender lateral process. The large arms of the epan- 

 drium and the dorsal extension of the hypandrium 

 tend to enclose what appears to be a thin, flat lamina, 

 which we believe constitutes the gonopod. 



Distribution : Ethiopian : Lophurodamalis fervida 

 Walker (1856); Mrtiventris Macquart (1846) [=im- 

 butus Walker (1854)]; natalensis Curran (1934); 

 simplex Curran (1934) ; speeiosa Loew (1857). 



