DASYPOGONINAB 



ROBBER FLIES OF THE WORLD 



145 



Thorax: The thorax is pollinose; pile of mesonotum 

 long, but rather scanty, acrostical bristles or hairs are 

 present but irregular; dorsocentral elements become 

 longer on the posterior half of the mesonotum. In the 

 type of genus the following complement of bristles is 

 present : no humeral, 4 notopleural, 4 supraalar, 3 post- 

 alar, 3 pairs of scutellar bristles. Scutellum flattened, 

 pubescent with a few marginal hairs. Propleuron with 

 abundant, long pile on all portions; some 6 pairs of 

 long, stout bristles on the collar but long, stiff pile only 

 on the dorsal posterior section. There are usually 1 

 to 3 slender, humeral bristles present. Mesopleuron 

 with abundant, long pile posteriorly and dorsally; 

 hypopleuron apilose; pteropleuron with a few hairs, 

 sometimes a single stout bristle. Hypopleuron apilose ; 

 metapleuron with a narrow vertical band of 15 or more 

 bristles, many of them stout. Pteropleural bristles 

 sometimes present. Metanotal slopes micropubescent 

 only ; lateral metasternum and the ventral metasternum 

 pilose; postmetacoxal area membranous. Tegula with 

 bristles and anterior basalare with 5 or more long, well 

 developed bristles, and additional hairs; this represents 

 a characteristic feature. 



Legs: The femora are rather stout without being 

 thickened or swollen. The dorsal pile of the hind fe- 

 mur is abundant, appressed and setate; ventral pile 

 of all moderately abundant, fine, rather long and erect. 

 The type of genus shows the following complement 

 of bristles : on the hind femur 4 or 5 long, stout lateral, 

 2 dorsal near the apex and also fine, short, apical medial 

 bristles. This tibia has 5 well developed dorsal, 4 lat- 

 eral, 4 or 5 ventral bristles; the ventral surface is ap- 

 pressed setate but without brush or setae. The apex 

 has 1 dorsal, 1 medial, 2 lateral, 3 ventral bristles. Mid- 

 dle femur with 1 stout bristle anteriorly and 1 

 posteriorly near the apex, its tibia has 6 slender, antero- 

 dorsal, 7 or 8 posterior dorsal, a like number of still 

 more slender posterior bristles besides 7 long, slender 

 ventral bristles. Anterior tibia with 7 or 8 short, an- 

 terodorsal, a like number of slender dorsal bristles and 

 posteriorly with 12 slender posterior elements which 

 are scarcely more than stiff hairs. Tibial apex with- 

 out spine, basitarsus as long as the next three segments, 

 which are beadlike; tarsi end in stout claws which are 

 only a little sharp, long pulvilli and empodium long and 

 basally swollen. 



Wings: The marginal cell widely open; anterior 

 branch of the third vein slightly sigmoid, ending a 

 little before the apex and arched gently at the base; 

 posterior branch ending a short distance behind the 

 apex. The first posterior cell is widely open, fourth 

 narrowed, sometimes considerably and closed with a 

 short stalk in some species. The anal cell is usually 

 widely open ; it may be closed in the margin or narrowly 

 closed in those species which have the fourth posterior 

 cell narrowly closed. Second basal cell with the middle 

 vein short, or almost wanting; alula short; the ambient 

 vein complete. 



Abdomen : The abdomen is cylindrical, or with paral- 

 lel sides and slightly flattened in the middle of the 



tergites. It is as wide as the mesonotum and bears 

 short, fine, appressed, suberect pile; it is usually 

 strongly pollinose and usually banded or spotted. 

 Scylaticus leoninus is an exception in that the abdomen 

 is everywhere densely long, erect pilose, the pile 

 coarse, stiff and brownish yellow. Male with eight ter- 

 gites, the seventh and eighth both reduced to from 

 one-half to two-thirds the length of the sixth ; sometimes 

 only a minute trace of the eighth segment is exposed. 

 Female with eight tergites, the eighth one-half as long 

 as the seventh. Male terminalia rotate one-half; con- 

 spicuous. Epandrium large, elongate, completely di- 

 vided into forceps; gonopod conspicuous and well 

 developed, the hypandrium large, triangular and un- 

 divided. The female acanthophorites bear some 5 pairs 

 of rather inconspicuous, lateral, spoonlike spines; 

 the ventral plate is more or less pinched together and 

 divided nearly or quite to the base. 



Distribution : Neotropical : Scylaticus cruciger Her- 

 mann (1921) ; distinguendus Lynch Arribalzaga 

 (1881) ; fulvicornis Macquart (1849) ; nitidigaster 

 Macquart (1849); philippi Schiner (1868); rubripes 

 Bigot (1878); ruftcauda Bigot (1878); tricolor Phi- 

 lippi (1865) ; venustus Philippi (1865). 



Palaearctic: Scylaticus degener Schiner (1868); 

 degener lutescens Engel (1930) ; miniatus Becker 

 (1915) ; semizonatus Becker (1906). 



Ethiopian: Scylaticus albipilus Becker (1923); al- 

 bofasciatus Engel (1932); argyroj/us Engel (1932); 

 barkeri Bromley (1947) ; costalis Wiedemann (1819) 

 \_ = laticinctus Loew (1858)]; engeli Bromley (1947); 

 exquisitus Engel (1932) ; leoninus Engel (1932) ; mar- 

 ginatus Engel (1932); pantherinus Bigot (1878); 

 punctatus Engel (1932) ; quadrifasciatus Engel and 

 Cuthbertson (1934); rufescens Ricardo (1900); vari- 

 pennis Ricardo (1925) ; zonatus Loew (1858). 



Oriental : Scylaticus indicus Bromley ( 1938 ) . 



Country unknown: Scylaticus histrio Wiedemann 

 (1828) ;nomada Wiedemann (1828). 



Pycnomerinx, new genus 



Type of genus : Pycnomerinx annulatus, new species. 



Related to Scylaticus Loew from which it is separated 

 by the rather long though slender microsegment at- 

 tached to the long, slender, third antennal segment, 

 which third segment is much shorter than in Scylaticus 

 and more slender ; also by the dense and quite long and 

 extensive mystax of the facial gibbosity and by the 

 unusually long, large, swollen palpus. Second segment 

 of the palpus densely covered below with long, coarse, 

 bristly pile. First segment of all of the tarsi quite short, 

 especially on the first four legs. Length 17 mm., includ- 

 ing antenna. 



Head, lateral aspect : Face moderately extensive and 

 gently rounded on the lower three-fifths, the upper 

 face barely extended beyond the eye profile, the cheeks 

 short and bare, the subepistomal area oblique, with a 

 conspicuous, medial ridge or carina. Occiput compara- 

 tively tumid and conspicuous from the lateral aspect 



