DASTPOGONINAB 



ROBBER FLIES OF THE WORLD 



281 



veloped ; the row of dorsocentral bristles is initiated well before 

 the transverse suture. Scutellum with a pair of stout, large, 

 marginal bristles. Region of postscutelluin without lateral pile. 

 Legs slender, with few bristles. The apical spine of the anterior 

 tibia is sharp like a stiletto. Wings with the fourth posterior 

 cell open. Abdomen slender and elongate. Genitalia of male 

 globose ; genitalia of female with spines. 



This genus is close to Macrocolus Engel, and in 

 certain respects also close to Mirolestes Curran and 

 Austenmyia Carrera. It is distinguished from all of 

 these others by the presence of bristles on the margin of 

 the scutellum. From Macrocolus it is separated by the 

 great development of dorsocentral bristles and by the 

 presence of dense pollen over the body which leaves it 

 completely without lustre ; from Mirolestes, by the pres- 

 ence of the open fourth posterior cell and by the form 

 of the antenna; and from Austenmyia, by the length of 

 the first segment of the antenna, two times larger than 

 the second, and by the form of the third antennal 

 segment. 



Distribution : Neotropical : Tocantinia miser "Walker 

 (1854). 



Genus Austenmyia Carrera 



Figures 519, 1123, 1132 



Austenmyia Carrera, Papels Avulsos Dep. Zool. Sao Paulo, 

 vol. 12, p. 104, 1955. Type of genus: Austenmyia amazona 

 Carrera, 1955, by original designation. 



The following is Carrera's description in translation. 



The head is a little wider than the thorax. The face is 

 plane and in extent three times the surface of the front, and 

 without pile. The mystax is composed of some fine bristles 

 disposed in a transverse line over the upper margin of the 

 buccal cavity ; proboscis cylindrical. Palpus with the second 

 segment developed, and fusiform and in length one-fourth as 

 long as the total length of the proboscis. The ocellar cal- 

 losity has 2 small bristles. Antenna with the first two segments 

 alike in length; each of these segments are as long as the 

 length of the last segment of the palpus. Third antennal 

 segment with the same length as the basal two segments of the 

 antenna together; at the apex it has a dorsal concavity and 

 the upper edge of this concavity sharp and spine-like. Pro- 

 sternum reduced to 2 plates between the anterior coxae. 

 Mesonotum with lateral and dorsocentral bristles well devel- 

 oped; the dorsocentral bristles make two rows of seven 

 elements each that begin in the anterior quarter of the pre- 

 scutum. Scutellum without bristles; postscutellum without 

 pile on the lateral callosity. 



Legs slender and elongate; apical spine on the anterior 

 tibia small. Wings with the fourth posterior cell and anal cell 

 open. The abdomen is a little larger at the base and two 

 times as long as the thorax. The genitalia of the female is more 

 or less globose with recurved spines. 



This genus presents characters intermediate between Macro- 

 colus Engel and Mirolestes Curran. It is distinguished from 

 Macrocolus by the form of the antenna and by the cover of the 

 body, opaque and without lustre; from Mirolestes it is distin- 

 guished by the open fourth posterior cell, by developed dorso- 

 central bristles and the pile of the ocellar callosity. 



Distribution: Neotropical: Austenmyia amazona 

 Carrera (1955). 



Genus Araiopogon Carrera 



Figures 555, 1157, 1166, 1762, 1853, 1858 



Araiopogon Carrera, Arq. Zool. Sao Paulo, vol. 7. p. 122, 1949. 

 Type of genus : Dasypogon gayi Macquart, 1838, by original 

 designation. 



Medium size flies of short, reduced pile, the bristles 

 short and stout but chiefly confined to the tibiae and 

 tarsi and reduced upon the face and mesonotum. 

 Closely related to Saropogon Loew. The epandrium 

 or ninth tergite of the male is developed into an upper 

 forceps instead of being split only along the medial 

 bine. Length 11 to 15 mm. 



Head, lateral aspect: The face is very short and 

 scarcely visible on the upper portion, a little more con- 

 spicuous below due to the recession of the eye; the 

 whole face is vertical and plane and rather short in 

 length. The eye is somewhat more narrow below, 

 gently convex behind, more strongly in front, longest 

 at the level of the antenna. The occiput is rather prom- 

 inent, but its thickness increases medially. The pile 

 of the occiput everywhere bristly, the lower pile abun- 

 dant, rather long and continued as a wide, subocular 

 band up to and across the upper portion of the head 

 behind the vertex. The more anterior elements on the 

 upper half are developed into rather stout, curved 

 bristles and those behind the vertex are proclinate. 

 The proboscis is strongly compressed laterally with 

 plane or slightly concave margin ventrally, high and 

 strongly arched beginning at the basal third at which 

 point the medial ridge is high and conspicuous; the 

 base is considerably reduced in height; on the outer 

 dorsal aspect the proboscis is tapered down to an un- 

 usually small, rounded point. From the upper aspect 

 it is tapered to the middle, from which point to the 

 base. The apical pile is fine and scanty ; in the middle 

 below is a tuft of long, stiff hairs in a close set row of 

 6, and additional long hairs are scattered basally below. 

 Palpus clearly of two segments, the second segment 

 frequently held at a strong angle ; first segment is ex- 

 cavated, the second microporate, densely covered with 

 many stiff bristles on all sides except medially and 

 reaching almost to the apex. 



The antenna is attached at the upper third, a little 

 longer than the head and slender, the first segment 

 slightly longer than the second, the third segment iy 2 

 times as long as the first two, slightly widened towards 

 the middle; beginning at the outer fifth it is gently 

 tapered to a blunt, oblique, truncate apex and the apex 

 bears a spoon-shaped microsegment which carries a 

 short, dorsal spine. Pile of the first segment abundant, 

 long and bristly, especially below and laterally ; second 

 segment with fewer similar bristles but with 1 or 2 

 which are longer and stouter. Sometimes the micro- 

 segment of the antenna is held at an oblique angle and 

 instead of being spoon-shaped is short and cylindrical, 

 oblique at its apex and carrying a spur. 



Head, anterior aspect : The face below the antenna is 

 more than a third the head width and divergent below. 



