DASYPOGONINAE 



ROBBER FLIES OF THE WORLD 



141 



continuous with a postvertical patch of 9 bristles. The 

 proboscis is comparatively large, somewhat compressed 

 laterally, especially on the outer half; the base is swol- 

 len, the medial ridge prominent, especially over the 

 middle and basal portion. The upper surface of the 

 proboscis is gently arched, the lower surface slight ly 

 concave, the apex bluntly pointed. Palpus large, the 

 first segment is hemicylindrical and excavated, the 

 second clavate and porate, with numerous stout bristles. 

 The antenna is attached near the upper third of the 

 head and is a little longer than the head. The first 

 two segments are subequal and together shorter than 

 the third segment, and each bears numerous bristles 

 and bristly setae above and below. Second segment 

 with at least 3 longer, stouter, ventral bristles. The 

 third segment is slender, little or no wider than the 

 second segment, of nearly uniform length, a little ta- 

 pered near the apex and with numerous bristles 

 dorsally. At its apex is a short, fused microsegment 

 with an oblique, open pit and a spine. 



Head, anterior aspect: The head is unusually wide 

 and the eyes flattened anteriorly, the central facets 

 greatly enlarged. The face is densely pollinose, without 

 pile, and bears above the epistoma a single row of 

 very stout, long bristles consisting of 6 to S pairs. 

 Subepistomal area large, either oblique or nearly verti- 

 cal. Front as wide as the face, pollinose, with a row 

 of 5 or 6 slender bristles along the eye margin. The 

 vertex is moderately excavated and has 1 or 2 pairs of 

 long, stout bristles between the posterior ocelli. 



Thorax : The thorax is dull, the pile reduced to fine, 

 scattered setae. There is an acrostical and a dorso- 

 central row of bristles, the latter with 3 or 4 long ele- 

 ments posteriorly. The lateral complement of bristles 

 contains 2 or 3 anterohumeral, 1 posthumeral, 2 or 3 

 notopleural, 2 supraalar, 2 postalar, and 1 to 2 pairs 

 of usually crossed scutellar bristles. Propleuron with 

 slender bristles on the collar; on the posterolateral 

 element is a dense tuft of bristly pile and on the lateral 

 propleuron a single stout bristle. Sternopleuron with 

 a tuft of many coarse hairs. Metapleuron with a verti- 

 cal row of 4 to 11 bristles, often stout. Remaining 

 pleuron without pile. Metasternum with scattered, 

 long hair. Postmetacoxal area membranous; prester- 

 num dissociated. 



Legs : The legs unusually densely setate, the bristles 

 reduced. The hind femur has only 2 stout bristles; 

 these are lateral bristles on the basal third. Middle 

 femur with 1 or 2 anterobasal, 1 posterobasal, and 

 1 posteroapical bristle. The anterior femur has 4 

 posterior and 1 anterior bristle on the basal third. 

 Tibial bristles comparatively short and stout; hind 

 tibia with 3 dorsolateral and 2 dorsomedial, 3 ventrolat- 

 eral, and 3 weak ventrobasal bristles. Anterior tibia 

 with 4 and middle tibia with 5 bristle rows, usually 

 containing 4 elements each. The anterodorsal elements 

 of the middle tibia and the single ventral distal element 

 of each tibia is exceptionally stout and long. Protib- 

 ial apex without spine. Claws sharp, only slightly 



curved, the pulvilli and the flat empodium are each 

 long. 



Wings : The marginal cell is open but reduced at apex. 

 The fourth posterior cell is closed and stalked and the 

 end vein of this cell and the lower end vein of the discal 

 cell are nearly aligned. Anal cell narrowly open. The 

 venation is therefore quite like Diogmites Loew. 



Abdomen : The abdomen is elongate, cylindroid, very 

 slightly tapered. At the base not quite as wide as the 

 mesonotum in most species. The pile of the abdomen 

 is reduced to numerous, fine, small, appressed setae. 

 Bristles are restricted to the first tergite, where there 

 may be from 3 to 10 pairs. Males with eight tergites, 

 the last quite short. Females with eight tergites, the 

 last being at least half as long as the seventh. Males 

 with epandrium small and fully cleft, the sides tightly 

 apposed, except apically. The gonopod is moderately 

 large, the hypandrium large and extensive; terminalia 

 fully rotate. Females with 6 pairs of stout, long, sharp 

 spines on the acanthophorites and additional, ventral, 

 spinous setae. 



Distribution: Neotropical: Archilestris capnopterus 

 Wiedemann (1828) [ = albitarsis Macquart (1846)]; 

 excellens Enderlein (1914) ; fulvigaster Bigot (1878) ; 

 longipes Macquart (1838) ; magnificus Walker (1854). 



Genus Dicranus Loew 

 Figubes 163, 476, 948, 957, 1696, 1819, 1934 



Dicranus Loew, Bemerkungen tiber die Familie Asiliden, p. 13, 

 1851. Type of genus : Dasypogon rutilus Wiedemann, 1821, 

 by monotypy. 



Macronix Bigot, Ann. Soc. Ent. France, ser. 3, vol. 5, p. 549, 

 1857. Type of genus: Dasypogon longiungulatus Mac- 

 quart, 1849, by monotypy. 



Large, dark colored and rather stout, elongate flies 

 of bare aspect due to the reduced pile; bristles are 

 quite stout but not very numerous. They will be 

 quickly recognized by the long, stout, nearly straight 

 claw, which appears to have a second, shorter, toothlike 

 claw at its base; this additional clawlike structure is 

 the exaggerated, apical bristle of each side of the end 

 tarsal segment. Pulvilli absent and empodium re- 

 duced to a tiny stub. Length 25 to 35 mm. 



Head, lateral aspect: The face is moderately de- 

 veloped and becomes a little more prominent below, 

 chiefly because the recession of the eye exposes the face 

 to a greater extent. Across the middle the face is very 

 slightly concave. Occiput only moderately developed 

 and only submedially developed. It bears below 

 rather long, dense, silky hairs which change below the 

 middle to weak bristles; at the upper third the bristles, 

 while still comparatively slender, are stronger, long, 

 and curved. Ventral portion of the head behind the 

 proboscis with a dense fringe of quite long, yellow 

 pile. Proboscis of moderate length, held obliquely for- 

 ward or downward ; the lower surface is nearly plane, 

 the upper surface rather strongly arched and accen- 

 tuated by the prominent dorsal keel. Apex with only 



