Empididae. 145 



Empid as prey for H. pruinosa M. Howlett (Entom. Month. Mag. 

 XLIII, 1907, 231) mentions Simulium latipes M. and small Chirono- 

 mids as prey for H. maura. The species have never been taken 

 with prey except when flying in the air, and when a pair in copula 

 is taken, they seem always to have a prey with them, and the facts 

 with regard to this phenonienon are somewhat curious. For several 

 species it has been observed, that when they are taken with a prey, 

 this latter is enveloped in a little web; this was first recorded by 

 Girschner (Entom. Nachricht. XV, 1889, 221) for H. maura and 

 interstincta, and later by Mik (1. c.) for H. aeronefha and pruinosa. 

 Howlett (1. c.) mentions it with regard to H. maura. I have myself 

 made the same observation with regard to H. pubipes. I observed 

 this species at Tisvilde in July 1909; in the evening the species was 

 seen sitting on the white wall of the hotel, and eacli had a small 

 Chironomus in the mouth; (as remarked above the species of Hilara 

 have elsewhere only been taken with prey when flying) ; when the fly was 

 caught or frightened, so that it flew away, the prey was left on the 

 wall, and by examining it I found it enveloped in a small web, 

 apparently consisting of only a few threads; the specimens of the 

 Hilara were all males. The species was also taken flying in the 

 evening high in the air in copula and with prey. Thus five species: 

 H. maura, interstincta, pubipes, aeronetha and pruitiosa are now 

 known to make these webs. From the various observations it is 

 clear, that it is only the males which make the web^ that this is 

 produced from the mouth, and that it is used to envelop the prey 

 in; it is probable that more or all Hilara species produce such a 

 web. The prey seems always to be caught in the air, and this seems 

 again to be in connection with the copulation, the male probably 

 attracting the females with the food, the facts thus being similar to 

 what is recorded above under Empis. 



Besides the mentioned five species still another species, H. sartor 

 Beck., makes a web, but this is much larger, and the males are seen 

 flying with it. H. sartor and its web has given rise to a whole 

 literature (by Osten Sacken, Becker, Mik, Girschner, Verhoeff, Hand- 

 lirsch), in which very different opinions as to the origin of the web, 

 its use and the way in which it is carried are advanced (see Mik, 

 Wien. ent. Zeitg. XIII, 1894, 273). It seems to me somewhat probable, 

 that the web may be of the same nature and origin, and chiefly of 

 the same use as the webs in the other species, perhaps at the same 

 time acting as a means of enticement for the females, but I can 

 othervvise say nothing about it, and in comparison with the curious 



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