DASYPOGONINAE 



ROBBER FLIES OF THE WORLD 



91 



trally and a conspicuous, transverse, dorsal row of stout, 

 long, sharp, spinous bristles; there are 6 of these bris- 

 tles on each side above and 4 to 6 laterally. The pro- 

 boscis is slender, directed forward, extending a short 

 distance beyond the face; in some species the base is 

 noticeably swollen and with a few scattered hairs ven- 

 trally on the basal half; apical pile fine, restricted to 

 the tip, and extending outward. Palpus small, com- 

 posed of two segments, the basal segment minute, the 

 terminal segment longer, slender, attenuate, nearly bare, 

 porate, with only a few scattered hairs arising from the 

 ventral side ; it is rather similar in f orm to the palpus 

 of the Stichopogonini. The antenna is attached shortly 

 above the middle of the head and rather short; in the 

 type of genus it is distinctly shorter than the head ; and 

 as long as the head in other species. The first two 

 segments are nearly subequal and together are as long 

 as the oval, slightly flattened third segment; apex of 

 third segment with a minute dorsal spine and without 

 microsegment. Middle base of the first segment with 

 a single long, quite stout, spinous bristle. 



Head, anterior aspect : The head is of moderate width, 

 the face one-fifth of head width and with parallel sides. 

 The face is densely pollinose. with a few short, scattered 

 hairs over the middle. The mystax confined to the ven- 

 tral elevation, where moderately stout bristles extend 

 obliquely forward and downward beyond the proboscis 

 and arise from a more or less triangular patch. Cheeks 

 absent. Subepistomal area small, concave, bare and 

 nearly horizontal. The front is distinctly but moder- 

 ately divergent and the vertex of about the same width ; 

 both pollinose, the former has a few minute hairs on the 

 sides and on each of the midfrontal ridges. The ocel- 

 lar protuberance of moderate height with slanting sides 

 and with a few exceptionally minute hairs. 



Thorax : The thorax is elongate, the mesonotum low, 

 uniformly convex and the whole thorax uniformly pol- 

 linose. The mesonotal pile is dense, minute, flat ap- 

 pressed, setate and undifferentiated. The thoracic com- 

 plement of bristles consists of stout mesonotal bristles : 

 1 notopleural, 1 supraalar, 1 postalar, and a scutellar 

 pair. Propleuron with only fine pile. Metapleuron 

 with a double row of very slender bristles or bristly 

 hairs, on one species a single row of 4 rather stout 

 bristles. Upper mesopleuron and the upper corner of 

 the sternopleuron and the posterior hypopleuron with a 

 patch of fine pile. Metanotal callosity micropubescent 

 only ; lateral slopes of the metasternus with pile. The 

 ventral metasternum broadly chitinized and pilose. 

 Postmetacoxal area membranous. Presternum not or at 

 most slightly dissociated posterolaterally. 



Legs : All the femora are stout, the hind pair a little 

 swollen distally, the legs everywhere densely and 

 minutely appressed setate and shining, the few bristles 

 moderately stout. The hind femur has a transverse 

 dorsal pair of bristles on the outer fifth and there are 3 

 others which are smaller and set transversely at the 

 apex ; ventral surface with only minute pile. Hind tibia 

 with a single dorsolateral at the outer fourth, 2 ventro- 

 lateral at the middle and outer fourth, its apex with 5 



bristles. Middle femur with 2 bristles dorsally at the 

 apex, in some species with only fine, longer hairs. 

 Middle tibia with 3 dorsal, 1 ventral, 1 anteroventral, 

 and 1 anterior bristle. Anterior femur with 3 bristles 

 at the apex, or sometimes only 1. The anterior tibia 

 with 2 strong posteroventral bristles and 1 or 2 minute 

 dorsal bristles. Claws sharp, the hind pair strongly 

 curved, the pulvilli long, the empodium long and 

 slender. 



Wings : The marginal cell open, second vein not at all 

 recurrent ; first posterior cell widely open, fourth pos- 

 terior cell and the anal cell closed and with stalk ; the 

 second basal cell ends in three veins and the ambient 

 vein is complete. 



Abdomen: The abdomen is robust, as wide as the 

 thorax basally, sometimes with the sides nearly par- 

 allel, or very slightly tapered. The pile is dense, 

 minute, quite flat appressed. The abdominal bristles 

 are stout, 2 to 3 on the sides of the first tergite, 2 later- 

 ally on the second and third tergites and at least 1 on 

 the remaining tergites, with strong bristly hairs on the 

 last tergite. Male with 6 tergites, the last being large 

 with curved sides. Female with 6 tergites and a linear 

 trace of a seventh. Male terminalia rotate one-half 

 with a characteristically arched, bowl-shaped protuber- 

 ance from the large epandrium, which is ventral in 

 position. Gonopod small, short, with slender apical 

 process. Hypandrium very short or absent. Genital 

 cavity exposed but deeply recessed in depth. The 

 whole structure is reminiscent of Hoplistomerus Mac- 

 quart. Female terminalia short and inconspicuous, 

 without spines and recessed beneath the last tergites. 



These flies frequent low vegetation where the sun- 

 light falls upon it. They are often associated with 

 desert rosette plants but in such situations they hide 

 from the direct rays of the sun beneath these plants. 

 Also they are found on the edges of woods in south tem- 

 perate, forested country. 



Distribution: Nearctic: Psilocurus oirdi Curran 

 (1931) ; modestus Williston (1893) ; nudiusculus Loew 

 (1874); puellus Bromley (1934); reinhardi Bromley 

 (1951). 



Neotropical: Psilocurus camposi Curran (1931); 

 caudatus Williston (1901). 



Martinia, new genus 



Type of genus : Martinia moloch, new species. 



Related to Psilocurus Loew, but distinguished from 

 this genus by the presence of a distinct, short, conical 

 microsegment on the third segment of the antenna. The 

 marginal cell is closed and stalked ; the second vein is 

 recurrent. The quite long, slender, ribbonlike pulvillus 

 separates it from Macahyba Carrera. Length 8-11 mm. 



Head, lateral aspect : The occiput is prominent below, 

 less so in the middle and not at all above. The face is 

 very short and plane with the eye beneath the antenna 

 but since it is almost straight in profile it is moderately 

 prominent below as the eye margin recedes backward. 

 Above the epistoma it is a little less convex than Psilo- 

 curus. Proboscis rather slender, bluntly rounded at the 



