ENTOMOLOGY IN OUTLINE DIPTERA. 87 



Few of the families of this suborder are of interest to us from an 

 economic viewpoint, as most of those mentioned have no direct bearing 

 upon our welfare; they may, therefore, be dismissed with a bare men- 

 tion. Some, however, are of more importance, as among them we find 

 some of our most beneficial insects, our friends, as well as some that 

 are very destructive, or, at least, very injurious to us. 



The family Psyehodidse consists of small flies very much resembling 

 moths in appearance, and are often found on the under side of leaves. 



The family Tipulidse includes the crane-flies, sometimes popularly 

 called daddy-long-legs. The larvae of these flies live in the ground and 

 are very tough and wiry, resembling wire worms in this respect. They 

 live on grass and grain roots and may become very destructive. Some- 

 times they are so numerous as to kill out lawns in which they have 

 become established. There are a large number of species, ranging in 

 size from a gigantic insect, an inch and a half in length, with a spread 

 of leg several inches in diameter, to some not larger than mosquitoes, 

 which they greatly resemble in general structure. This family is 

 representative, so far as the structure is concerned, of a large group, 

 the Midges, which resemble them. In these the bodies are long and 

 tapering, the legs generally very long and usually widely spread, so that 

 the insect has the appearance of walking on stilts. 



The family Blepharoeepidse. the net-winged midges, includes several 

 families of aquatic insects, somewhat resembling mosquitoes in form, 

 but different from them in wing venation. They breed in swiftly 

 running water, and in some species there are two forms of females, one 

 of which is blood-sucking, while the other lives by sipping nectar. 



The family Dixidse is another family of midges also resembling mos- 

 quitoes, and differing from the former family in wing venation. m 



The family Culieidse is one alto- 

 gether too well known, as it is in 

 this that we find the whole abom- 

 inable race of mosquitoes. This is 

 not a very large family, although 

 it is perhaps one of the worst ene- 

 mies with which the animal world, 

 including man himself, has to con- 

 tend. Members of this family are 

 found the world over. In some 

 sections of the tropics they are so 

 bad as to render the places infested 



_ . FIG. 75. Adult female of Ciilcx pipi' *. 



by them uninhabitable, and miners enlarged. (Miss. Agr. EX P . station.) 



