DASTPOGONINAE 



ROBBER FLIES OF THE WORLD 



89 



the upper three-fourths of the face has short, sub- 

 appressed pile, the ventral fourth slightly convex and 

 bearing a triangular patch of numerous, moderately 

 long, stout, curved, pale bristles, which extend down the 

 sides of the subepistoma only a short distance. Geno- 

 facial creases deep; the antenna rest on a very low 

 elevation which is shared by the upper face. The front 

 is longitudinally concave on either side, bare in the 

 middle, with numerous, long, fine, bristly hairs laterally 

 along the eye margin; it is distinctly wider than the 

 face and not or but slightly convergent dorsally. Ver- 

 tex rather deeply excavated; the ocellarium is large and 

 bears 3 or 4 pairs of short, slender, pale bristly hairs. 

 Anterior eye facets strongly enlarged. 



Thorax: Mesonotum without pollen or pubescence, 

 except above the wing. Pleuron micropubescent, the 

 peteropleuron and mesopleuron anteriorly bare. The 

 pile of the mesonotum is dense, but quite short, curled, 

 appressed and bristly setate. Differentiated acrostical 

 and dorsocentral bristles absent. Humerus with some 

 slightly longer suberect pile. In the type of genus the 

 following complement of moderately long and stout 

 bristles is present: 2 notopleural, 2 long and 2 short 

 supraalar bristles; postalar and scutellar margin with 

 only fine short hairs ; scutellum thick, convex, shining, 

 the surface with numerous, short, bristly hairs. Pro- 

 pleuron dorsally, laterally and ventrally with long pile, 

 fine below, stiff above, and 2 or 3 stiff bristly hairs. 

 Upper posterior sternopleuron, the posterior half of 

 the mesopleuron with considerable short pile ; the meso- 

 pleuron has a distinct though slender bristle. Ptero- 

 pleuron and posthypopleuron with a few, long, fine 

 hairs, amounting to 12 on the latter. Metapleuron 

 with a vertical band of numerous, long, slender, bristly 

 hairs; metanotal slopes micropubescent only. Lateral 

 metasternum and the chitinized but isolated ventral 

 metasternum rather densely long pilose. Postmeta- 

 coxal area membranous. Tegula pubescent only. 



Legs: All the femora are stout and swollen, the hind 

 femur a little more so than the others, and the thicken- 

 ing both dorsal and ventral. Pile of the femora dense, 

 appressed, fine and setate; ventral surface of hind 

 femur and of its tibia with dense, long, fine, erect pile; 

 the hind tibia quite thickened, narrowed only at the 

 immediate base and without ventral brush of setae. 

 The following complement of bristles present: on the 

 hind femur 1 strong lateral bristle at the outer sixth, 

 a weak dorsal bristle at the outer fourth, its tibia with 

 2 slender dorsomedial, but 4 quite stout dorsolateral, 

 and 6 similar ventrolateral, the apex with 2 medial, 1 

 dorsomedial, 1 dorsolateral, 2 lateral, and 6 ventral 

 bristles ; hind basitarsus stout and short, but as long as 

 the 2 succeeding segments ; middle femur with a dorso- 

 lateral bristle at the outer fifth, and a ventrolateral 

 bristle ; its tibia with a single anterior bristle near the 

 base, 3 anteroventral on the outer half, 2 short and 2 

 long anterodorsal, 4 posterodorsal, 4 long posteroventral 

 bristles ; anterior femur with only fine, short setae ; its 

 tibia with an anterior brush of setae beginning at the 

 base, 2 or 3 minute, anterodorsal bristles, 4 slightly 



longer posterodorsal and 4 long, basally stout, attenu- 

 ate, posteroventral bristles; apex without spine. All 

 the tarsi short and stout. All tarsi end in slender, 

 sharp claws, in long pulvilli, and in a long empodium 

 strongly swollen at the base. 



Wings: Marginal cell widely open but the cell is 

 wide distally, its apex strongly and rather abruptly 

 arched, the vein ending at a right angle. Anterior 

 branch of third vein strongly sigmoid and the second 

 submarginal cell strongly swollen at base. First and 

 fourth posterior cells closed and stalked. Anterior 

 crossvein enters the discal cell at the basal fifth ; middle 

 end vein of the second basal cell rather long, anal cell 

 closed and stalked, alula moderately wide, the ambient 

 vein ends at the anal cell. 



Abdomen : The abdomen is robust, nearly as wide as 

 the thorax, punctate, rather flattened over the middles 

 of the basal tergites, and with six tergites in the male, 

 all of nearly equal length, including the last one. The 

 pile of the abdomen is abundant, but rather short and 

 fine and largely appressed. Sides of the first tergite 

 with a few long, fine hairs and 4 or 5 long, stout bristles ; 

 remaining tergites without bristles. Male terminalia 

 rotate one-half, the epandrium deeply notched apically 

 but rather large and bulbous or swollen. 



Distribution : Palaearctic : Scytomedes haemorrhoid- 

 al'is Fabricius (1794) [=menstruus Roeder (ex Loew) 

 (1882), nubeculipennis A. Costa (1863)] 



Genus Macahyba Carrera 



Figubes 445, 876, 885 



Macahyha Carrera, Papers Avulsos Dep. Zool., Sao Paulo, vol. 

 8, no. 17, p. 203, 1947. Type of genus : Macahyha nordestina 

 Carrera, 1947, by original designation. 



Medium size flies of greatly reduced pile and with 

 a few stout bristles. Distinguished by the open mar- 

 ginal cell and the recurrent second vein, the excep- 

 tionally strongly arched base of the second submarginal 

 cell, the widely open first posterior cell and the pair of 

 stout, long scutellar bristles. Length 15 mm. 



Head, lateral aspect: The head is of medium length. 

 The face is straight in profile, very short on the upper 

 part, somewhat more conspicuous below due to the 

 posterior recession of the eye. Cheeks as prominent as 

 the face. The eye is slightly longer on the dorsal half, 

 but on its posterior portion equally developed above and 

 below, so that its posterior profile is nearly plane 

 throughout the middle. The occiput is moderately 

 thick, both above and below, with shaggy, long, ventral 

 pile and a submarginal, deeply placed row of stout, 

 conspicuous, spinous bristles beginning at the middle 

 of the occiput and continued well behind the vertex; 

 there are 9 on each side. The proboscis is short, ex- 

 tended scarcely or very little beyond the face, and 

 robust, with the apex slightly depressed dorsoventrally 

 and the pile reduced to a few long hairs below at the 

 base and a few short hairs at the apex ; medial carina 

 low. Palpus clearly of two segments, the first segment 



