334 



The Two-winged F^lies 



hair usually light brown or whitish in color. The wings are blotched with 

 brown or blackish. Anthrax contains numerous species with short proboscis, 

 and broad flattened body covered with short hair. The wings are either 

 clear or partly colored with brown or black. In the species of the genus 

 Exoprosopa (Fig. 468) the hair of the body is very short and often in silver}' 



bands across the abdomen, the pro- 

 boscis is short, and the wings usually 

 beautifully "pictured' 

 black. 



with brown and 



Fig. 468. 



^ _^_ . (Twice natural size.) 



Fig'. 468.— a bee-fly,' Exoprosopa sp.' (One and one-half times natural size.) 



Fig. 467. 

 Fig. 467. — A bee-fly, Bombylitis major 



In California the roads and paths, especially along streams and through 

 woods and parks, are made ahnost intolerable in part of the spring for driving 

 or bicycling because of hosts of small .slender blackish flies 

 in swiftly dancing swarms. The.se are dance - flies, 

 Empidida?, and their aerial dance is their mating flight, 

 r do not know that such hordes of dance-flies occur in 

 the East, but some species of 

 the family have the same danc- 

 ing habit there, and can be dis- 

 tinguished by it and by the 

 structural characters given in 

 the key. The midges, Chiront)- 

 midoe, also dance in swarms in 

 the air, but are readily dis- 

 _ tingui.shed from the Empidids 

 l( \V^ ^y ^^^^'^ small fragile body, 



and long many-segmented hairy 

 ^ntennx. All the dance • flies 

 are predaceous, sometimes 

 catching their prey in the air, 

 sometimes chasing it on the 

 ground. The larvae, slender cylindrical grubs living in the soil or under leaves 



Fig. 469. 



Fig. 470. 



Fig. 46Q. — Mouth-parts of a bee-flv Bombylius sp. 



(Much enlarged.) 

 Fig. 470. — .\ dance-fly, RImmphomyia longicauda. 



(Three times natural size.) 



