144 Orthorrhapha brachycera. 



prothoracic segment, the larva is thus amphipneustic. On the ventral 

 side of most abdominal segments there are small, transverse swellings 

 (Kriechschwielen). The pupa is pale yellowish to brownish; it has 

 two processes or teeth in front, at the bases of the diverging antennal 

 sheaths, and four long hairs; thorax has some similar hairs above 

 and below. The pupa of H. niveipennis has besides the two teeth 

 mentioned further two triangular teeth below the head, inwards to 

 the apices of the antennal sheaths; each of these teeth has a hair 

 standing close to it; the same two teeth or processes are found also 

 in the pupa of H. pilosa and matrona according to Beling, but are 

 not mentioned for the other species. The abdominal segments have 

 each above a transverse row of strong, short bristles or teeth of 

 unequal length and with some long hairs intermingled ; on the sides 

 and below there are long hairs. 



The larvæ live in humous earth on humid piaces in woods, and 

 may be taken in mole-casts, further among decaying leaves and in 

 decaying wood (Brauer took the larva o'i hirida in a decaying poplar); 

 they are certainly carnivorous. The pupæ are found in the same 

 piaces as the larvæ. The larvæ hibernate, and the transformation to 

 pupa and final development take place in the following spring or 

 summer. 



The species of Hilara are easily known by the almost always 

 thickened front metarsi in the male and by the long upper branch 

 of the cubital vein. They occur both in and near woods and on 

 fieids and commons, especially near water. They are often seen in 

 great numbers flying low above the surface of ponds, pools and 

 ditches; some species are flying higher, below the trees in woods; it 

 is generally only the males which fly in this way, but pairs in copula 

 may, however, also be seen. They are also seen in the evening flying 

 more singly somewhat high in the air, and then generally in copula. 

 They are carnivorous, feeding on other Insects, especially small Diptera. 

 I have taken H. puhipes with a Tachydromia and with a small Chi- 

 ronomus as prey, H. maura with Ghironomids, small Tipulids, small 

 beetles, a Myrmica, a Podurid and several other forms, and H. inter- 

 stincta with Ghironomids as prey. Poulton mentions in the work 

 cited above only one undetermined Hilara with Chirononms riparius 

 M. as prey. Girschner (Entom. Nachricht. XV, 1889, 221) mentions 

 small beetles and Aphids as prey for H. maura and interstincta, and 

 also the latter with the former as prey. Mik (Wien. ent. Zeitg. XI, 

 1892, 80) records small Phryganids and a Psocus as prey for H. 

 aeronetha, and the same author mentions (ibid. XIII, 1894, 283) 

 Simulium reptans L., Ptilonota centralis F., a Gecidomyid and a small 



