MEGAP0D1NAB 



ROBBER FLIES OF THE WORLD 



425 



Basitarsus with a conspicuous, distally extended lobe 

 or flange without teeth. All the basitarsi are un- 

 usually long and slender and in the male the anterior 

 basitarsus is as long as all the remaining segments ; the 

 second and third segments also long and slender. An- 

 terior basitarsus orange in color in the type of genus; 

 remainder of legs everywhere black ; all bristles and pile 

 black. Tarsi end in small, slender, sharp claws, well 

 developed pulvilli and fine, long, slightly flattened 

 empodium. 



Wings: The wings are long, slender and brownish 

 black, with slight purplish blue reflections. Marginal 

 cell narrowly closed with a short stalk ; anterior branch 

 of third vein sinuous, ending above the wing apex ; pos- 

 terior branch ends far behind the wing apex ; first pos- 

 terior cell extremely long and unusually narrow, widely, 

 open; fourth posterior cell closed with a long stalk; 

 anterior crossvein enters the middle of the discal cell. 

 The middle end vein of the second basal cell is moder- 

 ately long; anal cell long, narrow, closed with a short 

 stalk ; the alula wide, the ambient vein complete. 



Abdomen : The abdomen is as wide as the mesonotum 

 on the first tergite and the base of the second ; beyond 

 the second tergite the sides are nearly parallel or very 

 slightly widened in the male. Abdomen black with 

 brilliant purple and blue reflections. Second tergite 

 distinctly longer than the others, though not greatly 

 longer than the third ; remaining tergites progressively 

 shorter. Males with seven tergites, the seventh four- 

 fifths as long as the sixth, and beneath it apically the 

 edge of the eighth tergite can be seen. Female with 

 seven tergites, the eighth and beyond forming the ovi- 

 positor. Pile of abdomen abundant, appressed and se- 

 tate, a few fine, long hairs on the sides of the first tergite 

 and some longer setae on the posterior corners of the 

 second tergite ; the basal half of these tergites is largely 

 bare; the first tergite laterally has 5 pairs of slender 

 bristles. Male terminalia large, conspicuous, rotate 

 one-half with a deep, posterior cleft, which is the space 

 between gonopods as seen from above. Gonopod mas- 

 sive, with considerable depth and only a short, blunt, 

 true dorsal process. Epandrium uncleft, with long 

 proctiger and fused to hypandrium. Female termi- 

 nalia short and cylindrical, very slightly higher than 

 wide, the ninth and especially the tenth tergites quite 

 short; the eighth tergite appears to be quite separate 

 from the eighth sternite. This appears to also be true 

 of the ninth tergite. 



Distribution : Neotropical : Megapoda labiata Fabri- 

 cius (1805) [ = fcyanea Macquart (1834), frufimanus 

 Perty (1833]. 



Genus Doryclus Jaennicke 



Figukes 236, 647, 1278, 1287, 2104, 2118, 2169 



Doryclus Jaennicke, Abhandl. Senekenberg. naturf. Ges., vol. 6, 

 p. 366, 1867. Type of genus : Asilus distendens Wiedemann, 

 1828, by original designation. 



Ampyx Walker, List . . . Dipterous insects . . . British Mu- 

 seum, suppl. 3, p. 564, 1855. Type of genus: Asilus dis- 

 tendens Wiedemann, 1S28, as Ampyx varipennis Walker, 

 1855. Preoccupied, Crustacea, 1845. 



Small or medium size flies with slender wings and all 

 legs elongate and mostly slender. Characteristically 

 the long hind tibia is quite slender on the basal half, 

 becoming strongly dilated distally and on this swollen 

 part it bears on all sides dense, coarse, more or less ap- 

 pressed, black, bristly pile. Hind basitarsus likewise 

 swollen conspicuously and as long as all remaining seg- 

 ments, which are gradually reduced in size. These flies 

 are shining and polished with scanty, scattered pile and 

 bristly setae; bristles are chiefly restricted to the legs 

 and are sharp and thornlike. Pleuron especially pol- 

 ished and bare and the metanotum greatly swollen, 

 elongate and obliquely sloping backward and down- 

 ward. Face short, concave, the epistoma quite large 

 and oblique ; the long proboscis and long, large, curved 

 palpus are extended straight forward. Length exclu- 

 sive of legs 10 to 15 mm. 



Head, lateral aspect : The length is moderate with 

 the eyes slightly longer on the lower half and convex 

 both anteriorly and posteriorly. The face is well de- 

 veloped but exceptionally short vertically and strongly 

 concave. The prominent subepistoma is large and 

 oblique. The cheeks do not extend below the eyes. 

 Occiput almost obliterated in profile. There is a thin 

 line of white pubescence on the lower two-thirds of 

 the occiput as it extends medially inward, nearly plane 

 to the eye margin. Pile of lower occiput restricted to 

 a few bristly hairs in 1 row; these hairs placed deeply 

 medial, and on the upper third of the occiput somewhat 

 longer hairs mixed with weak, curved bristles. The 

 proboscis is quite elongate, thrust horizontally forward, 

 extending well beyond the antenna. It is rather 

 strongly compressed laterally, each side being gently 

 convex. The outer half of the ventral surface is quite 

 plane and before it basally is a ventral, submedial swell- 

 ing. Apex dorsally arched downward to a blunt point 

 with fine pile above and below. Beyond the middle 

 dorsally is a low keel which is not very long. Palpus 

 quite long and conspicuous, cylindrical, extended well 

 beyond the face and curved upward. It bears con- 

 siderable bristly pile on all sides. 



The antenna is attached at or above the upper fourth 

 of the head and is nearly as long as the head. First 

 segment robust and swollen with 4 or 5 dorsal bristles. 

 Ventral surface with at least 1 stout bristle and a num- 

 ber of coarse, bristly hairs. This segment is a little 

 longer than high. Second segment much smaller, with 

 bristly hairs below and with 2 to 3 conspicuous, and 

 stout, long bristles above. Third segment as long as 

 the first two combined, pyriform, with the basal sixth 

 no wider than the second segment and beyond this point 

 this se£rment is rather abruptly and strongly expanded 

 above and below until it is roughly rhomboidal. The 

 apical part of the third segment is also thick and 

 swollen medially ; the blunt apex bears a quite small 

 opening with minute, nearly concealed spine. 



