BEE, WINDOW, AND STILETTO FLIES. 



BOMBYLIID.E 



If you see a fuzzy fly hover in mid-air and suddenly 

 dart a few feet away to hover again, you may feel certain 

 that it is a Bee Fly. That name, and the "real" name for 

 the family is just as bad, has always confused me, as it 

 seemed to go with certain more bee-like Asilids, but it 

 does not. Plate LXVI shows samples of Bombylius 

 (larvae live in the nest of bees, such as Andrena) and 

 Anthrax (the larvae of some species of this genus are 

 probably parasites of Lepidoptera but those of others, 

 especially of those whose adults have wing-markings, are 

 parasites of Lepidoptera's parasites); Plate LXVII, of 

 Spogostylum, Systropus, and Exoprosopa. The Bombyliid 

 face is not hollowed out and the eyes, especially of the 

 males, almost or quite touch above; the proboscis has 

 broad tips and is sometimes very long and slender; the 

 wings often have dark markings. The beak is chiefly 

 used to sip nectar. The larvae feed upon the eggs or young 

 stages of grasshoppers, beetles (e. g. Cicindela), Lepidop- 

 tera, bees, and wasps. 



SCENOPINID.E 



We have only one genus, Scenopinus, of the Window 

 Flies and, of this, only fenestralis (Plate LXVII) is common. 

 It is bluish, with reddish-yellow legs; the head is placed 

 so low that the thorax seems quite convex. It is on our 

 windows because its worm-like larvae are under our carpets, 

 eating "moths." Each of the larva's abdominal segments, 

 except the last, is constricted, so that it appears to have 

 nineteen segments. 



THEREVID^E 



The Stiletto Flies are like delicate, long-legged Asilidae 

 but the front of the head is not hollowed out between the 

 eyes ; it may even be convex and the eyes of the males may 

 join on top. Their habits are those of the Asilidae. Psilo- 

 cephala (Plate LXVII) is a common genus. 



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