334 
The Two-winged Flies 
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 silvery 
bands across the abdomen, the pro¬ 
boscis is short, and the wings usually 
beautifully “pictured” with brown and 
black. 
Fig. 467. Fig. 468. 
Fig. 467.—A bee-fly, Bombylius major. (Twice natural size.) 
Fig. 468.—A bee-fly, Exoprosopa sp. (One and one-half times natural size.) 
In California the roads and paths, especially along streams and through 
woods and parks, are made almost intolerable in part of the spring for driving 
or bicycling because of hosts of small slender blackish flies 
in swiftly dancing swarms. These are dance-flies, 
Empididae, and their aerial dance is their mating flight. 
I 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, Chirono- 
midae, also dance in swarms in 
the air, but are readily dis¬ 
tinguished from the Empidids 
by their small fragile body, 
and long many-segmented hairy 
antennae. All the dance-flies 
are predaceous, sometimes 
Fig. 469. Fig. 470. 
Fig. 469.—Mouth-parts of a bee-flv Bombylius sp. 
(Much enlarged.) 
Fig. 470.—A dance-fly, Rhamphomyia longicauda. 
(Three times natural size.) 
ground. 
catching their prey in the air, 
sometimes chasing it on the 
The larvae, slender cylindrical grubs living in the soil or under leaves 
