548 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



long as the seventh. Pile of abdomen scanty, fine, ap- 

 pressed and setate with a little long, erect pile basaUy 

 on the sides of the first and second tergites. Stemites 

 with long, fine pile on the second and third, among 

 which are some long, stiff, bristly hairs. The bristles of 

 the abdomen are extremely weak and scarcely amoimt 

 to more than stiff hairs; there are 6 or 7 on the sides 

 of the first tergite and lateral patches of rather nu- 

 merous, appressed, long setae or bristly pile on the 

 sides of all the tergites and to some extent equally 

 weak, bristly pile along the lateral posterior margin. 

 Male terminalia large, conspicuous, the superior forceps 

 elongate and with a large, dorsal opening formed by 

 the apical processes curving to the midline. Termi- 

 nalia not rotate and of open type below exposing the 

 aedeagus. 



Distribution: Palaearctic: Rhadiurgus variabilis 

 Zetterstedt (1838). 



Ethiopian: Rhadiurgus notatus Bigot (1891). 



Oriental: Rhadiurgus ifidus Fabricius (1805). 



In this genus Melin (1923) describes and illustrates 

 the egg, larva and pupa of Rhadiurgus variabilis. 



Genus Astochia Becker 



FiQTJKES 376, 780, 1614, 1615, 2341, 2352, 2403, 2405 



Astochia Becker, in Becker and Stein, Ann. Mus. Zool. Acad. 

 Imp. St. Petersbourg, vol. 17. p. 538. 1913. Type of genus : 

 Astochia metatarsata Becker in Becker and Stein, 1913, by 

 monotypy. 



Rather large flies with a short, wide head. Tlie ab- 

 domen is robust at the base but narrower on the termi- 

 nal segments. They are easily recognized by the stout, 

 anterior basitai-sus and in males by the divergent, dorsal 

 and ventral portions of the terminalia and in females 

 by the long, extensive, slender, laterally compressed 

 ovipositor, which contains five segments. Related to 

 Neoitamus Osten Sacken. Length 16 to 30 mm. 



Head, lateral aspect : The head is comparatively short 

 and wide, the eyes strongly flattened m front. The 

 face is nearly plane with the eye on the upper half 

 with a low, gently rounded elevation below ; it is a little 

 more prominent because of the recession of the eye. 

 Occiput moderately prominent and the eye strongly 

 posteroventrally recessive on the lower fourth. The 

 pile of the occiput is dense, long and fine ventrally, 

 more coarse along the middle and above, and stout bris- 

 tles are usually restricted to 3 to 5 pairs placed dorsally 

 near the upper eye comers. The proboscis is of medium 

 size, rather strongly tapered and pointed on the outer 

 fifth and half of this portion bears long, stiff, bristly 

 hairs. It extends well beyond the face and is generally 

 held obliquely or even nearly horizontally forward; 

 the base is a little swollen. Palpus large, cylindrical, 

 with apical and terminal bristles, and stiff hairs extend- 

 ing to the base. The antenna is attached at the upper 

 third of the head and moderately long; the first seg- 

 ment is distinctly longer than the second. The third 

 segment is widest near the base, gently tapered to a 



narrow apex and is approximately as long as the com- 

 bined length of the first two segments ; it is generally 

 no thicker at any point than the second. A microseg- 

 ment is absent and the style is almost as long as the 

 first three segments, with bristle at the apex. On the 

 first two segments bristly hairs are chiefly distributed 

 along the ventral surface and dorsally at the apex. 



Head, anterior aspect: The head is wide; the face 

 below the antenna is about a seventh the head width 

 and strongly divergent below. The face is densely 

 pubescent and generally without pile on the upper half ; 

 the low gibbosity bears numerous, rather slender 

 bristles and long, bristly hairs over its medial portion. 

 The lower group of bristly hairs is often whitish with 

 some of its elements moderately stout, the more dor- 

 sally placed, slender bristly haii'S are often black ; simi- 

 lar elements are continued down the sides of the large, 

 oblique subepistoma. Cheeks moderately prominent 

 with a deep, lateral groove. The front is small, pubes- 

 cent, the subocular margin has a row of slender bristles 

 or bristly hairs continued on to the vertex, and medial 

 to this row anteriorly is a patch of 7 or 8 bristly hairs. 

 The front is slightly divergent; the vertex is barely 

 narrowed, moderately excavated with slanting, bristly, 

 pilose sides; the ocellarium is comparatively high, with 

 vertical sides ; a pair of slender bristles lies between the 

 ocelli and sometimes other hairs, and 4 or 5 pairs of 

 bristly hairs lie behind the ocelli. 



Thorax : The mesonotum is moderately high, the sur- 

 face pollinose and rather widely covered with scattered, 

 fine setae and bristly pile. There is a well differenti- 

 ated, broad band of acrostical pile and dorsocentral 

 elements are differentiated only behind tlie suture and 

 are usually quite slender, with sometimes 1 or 2 stout 

 elements. Humerus with long pile. The lateral com- 

 plement of long, stout bristles contains 2 notopleural, 

 1 supraalar, 1 suprapostalar, 2 to 3 postalar, and 2 to 5 

 pairs of scutellar bristles. Scutellum convex but with 

 distinctly impressed rim. The disc is coarsely or finely 

 pubescent and with scanty, erect, fine, bristly pile. 

 Pronotum with 3 or 4 bristles generally weak. Meso- 

 pleuron copiously, long, erect pilose over most of its 

 surface and also with abundant pile on the upper ster- 

 nopleuron, pteropleuron ; numerous, long, bristly hairs 

 on the posthypopleuron. Posterior basalare with a tuft 

 of bristly pile. Metapleuron with a vertical band of 

 numerous, slender bristles and bristly hairs. Metanotal 

 callosity with a large patch of coarse, erect pile. Pro- 

 sternum dissociated ; metasternum pilose ; the postmeta- 

 coxal area membranous. 



Legs: The legs are unusually elongate for members 

 of this subfamily, especially the hind femur and tibia. 

 The hind femur is more slender basally and is slightly 

 thickened distally ; of the three pairs, the middle pair is 

 the more swollen, its thickness increased only dorsally. 

 Pile of the legs abundant, appressed and setate dorsally 

 with the posteroventral surface of the first four femora 

 bare. Bristles are quite stout, but are markedly re- 

 duced ; the hind femur bears along the middle, 2 or 3 



