LAPI1RIINAE 



ROBBER FLIES OF THE WORLD 



359 



placed by rather long, stout bristles. Front very short, 

 polished and bare, with dense, fine pile laterally ; the 

 vertex is divergent and rather deeply excavated, as 

 wide or wider than the face with steeply slanted sides; 

 the ocellarium is small with very small ocelli and a 

 pair of long, quite stout, divergent bristles. Eyes 

 moderately enlarged centrally. 



Thorax : The mesonotum and pleuron pollinose and 

 dull. The pile of the mesonotum is very scanty, fine 

 and short over the middle but a little longer laterally 

 and in front of the scutellum. The medial pile is not 

 clearly differentiated in the acrostical area. Humerus 

 with 7 or 8 slender bristles; notopleuron with 4, supra- 

 alar region with 8 in a single row; postalar with 8, 

 scutellar margin with 7 or 8 pairs which are rather 

 long. The scutellum is exceptionally thick and con- 

 vex with a slightly impressed rim and abundant, fine 

 and rather long pile. Propleuron with dense, long 

 pile. Mesopleuron with some pile dorsally and poste- 

 riorly and with 2 or 3 stout, long bristles. Pteropleu- 

 ron with a tuft of long, stiff, bristly hairs along 

 the upper posterior margin. Hypopleuron and sterno- 

 pleuron with fine pile ; the metapleuron with a vertical 

 band of long, slender, bristly pile. Metanotal slopes 

 with abundant, stiff pile; tegula with short bristles. 

 Lateral and ventral metasternum pilose. Postmeta- 

 coxal area membranous; prosternum not dissociated 

 but greatly narrowed posterolaterally. 



Legs : The femora are stout without being especially 

 thickened; they bear abundant, moderately long, bris- 

 tly pile. Bristles present as follows: on the liind 

 femur there is 1 at the apex laterally, 1 sublaterally, 

 3 at the apex medially. This tibia bears 5 long, stout, 

 dorsal bristles. Middle femur with 2 bristles anteri- 

 orly beyond the middle, 3 near the apex posteriorly; 

 middle tibia with 8 or 9 very slender, dorsal bristles; 

 6 or 7 longer, slender, attenuate, posterior bristles and 

 a like number of similar posteroventral bristles; 

 anterodorsally there are 6 bristles, 2 of them beyond 

 the middle being especially stout. Anterior femur 

 with long, bristly hairs dorsally and several similar 

 rows ventrally; the tibial bristles are very slender, 

 long and attenuate, and consist of about 8 pairs in 2 

 rows dorsally, and a like number still longer below. 

 Tarsal segments are short and end in stout, rather 

 sharp claws bent at the apex, well developed pulvilli, 

 and a stout bladelike empodium. 



Wings: The wings are large, apically pointed but 

 broad basally. The marginal cell is closed with a 

 long stalk. The anterior branch of the third vein ends 

 shortly above the wing apex, the posterior branch ends 

 far behind the apex. First posterior cell open but 

 greatly narrowed throughout. Fourth posterior cell 

 closed with a long stalk ; lower vein ending the discal 

 cell is pulled backward so that the cell appears to end 

 with one vein. Anal cell closed with a long stalk. 

 Alula large; ambient vein complete. The wings are 

 often banded with brownish black on the base and 

 apex, leaving the middle part opaque, creamy whitish ; 

 combined with the bright colored fringes of pile on 



the abdomen, they copy certain tropical bees of the 

 genus Eulaema. 



Abdomen: The abdomen is very broad and only 

 gently convex; in consequence it is largely flattened 

 over the middle. The abdomen is considerably wider 

 than the thorax. Pile of the abdomen dense but matted 

 and flat appressed, forming bright colored fringes 

 usually along the posterior margin; these are longer 

 laterally only on the terminal segments. First ter- 

 gite with 5 or 6 bristles laterally. Seven tergites are 

 present in the male, the seventh as long as the sixth. 

 Eight are present in the female, with the eighth well 

 developed but greatly narrowed and narrowly coni- 

 cal. Male terminalia large and elongate, rotate one- 

 fourth to the right but with a bulblike or bowllike 

 ventral epandrium less conspicuous than is present in 

 Laphria Meigen. Female terminalia slender, elon- 

 gate, slightly compressed laterally, obliquely truncate 

 with a fringe of fine terminal bristles. Eighth sternite 

 produced posteriorly and at or near the apex beset with 

 several long, stout bristles and long, stiff hairs. 



Distribution: Neotropical: DasyUis albicollis Bigot 

 (1879) ; croceiventris "Wiedemann (1821) ; erythrura 

 Hermann (1912); fascipennis Macquart (1834) 

 [ = praepofens Macquart (1846)]; haemorrhoa Wiede- 

 mann (1830). 



Ethiopian: Dasyllis usambarae Lichtwardt (1907). 



Probably Dasyllis usambarae, described from East 

 Africa, belongs in Hyperechia Schiner. 



Genus Hyperechia Schiner 



Figttees 277, 277a, 643, 1258, 1267, 1580, 1609, 1812, 2093, 2130 



Hyperechia Schiner, Verh. zool.-bot Ges. Wien, vol. 16, p. 673, 

 1866. Type of genus : Laphria xylocopiformis Walker, 

 1849, by original designation. 



Extremely large, exceptionally robust, broad flies 

 which are also characterized by the dense, long, brushes 

 of pile borne on the femora, tibiae and the more basal 

 segments of the tarsi. There is a striking similarity 

 or mimicry between these flies and the large carpen- 

 ter bees belonging to the genus Xylocopa. The head 

 is wide, the face exceptionally broad, the pile extremely 

 short and appressed over the middle portion of the 

 thorax and abdomen. The wing is exceptionally broad 

 at the base, gradually tapering to a pointed apex. 

 First posterior cell greatly narrowed throughout its 

 length, closed with a short stalk. Length 22 to 35 mm. 



Head, lateral aspect: The face is rather short on 

 the upper half, gradually produced below until some- 

 what more prominent and sometimes with a shallow, 

 transverse depression separating the lower, more con- 

 vex portion of the face. The eye is rather short and 

 wide, though not greatly flattened; it is characteris- 

 tically narrowed ventrally due to the eye being 

 gradually recessive ant erovent rally. The occiput is 

 prominent, except at the immediate vertex ; it is more 

 tumid medially and on the dorsal part slopes down to 

 the eye margin. Pile of the occiput is dense and fine 



