CLASS I. INSECTA: ORDER 5. DIPTERA. 



581 



to every 



one ; 





GNATS. 



between 



the MosQuiTos, Culex musguito, wMcli are very nearly allied to the gnats, are still 



greater pests. In some parts of America, 

 and in India, the inhabitants are compelled 

 to protect themselves when asleep, by 

 means of fine gauze curtains, from the 

 attacks of these bloodthirsty little crea- 

 tures. 



The female of the Common Gnat, Cu- 

 lex pipiens, lays her eggs, two hundred 

 to three hundred in a year, one by one 

 in the water ; these are joined together, 

 and form a little raft, which floats on 

 the surface. They are hatched in three 

 days, and in fifteen days the larvae have 

 reached maturity. They still inhabit the 

 water, and are very active ; when about 

 to assume the imago state, the skin 

 which covered the pupa being loosened 

 from the animal within, and the space 

 ro being occupied with air, it floats upon the surface of the water ; the gnat breaks 



through the upper part, and stands on the skin 

 it has quitted, and which now serves as a little 

 boat, upon which it floats until it has attained 

 strength to fly. There are many species of gnats, 

 some of which are harmless ; others are not only 

 troublesome to man, but to cattle, beasts, and 

 birds, sucking tbeir blood, and causing the most 

 irritating pains and itchings in the skin. The 

 mosquitos, of which there are several species, are 

 hatched in nearly the same manner as the gnats. 



THE TIPULID^. 



These have the proboscis short, terminated 

 by a pair of fleshy lips, inclosing two bristles. 

 The Meadow-Tipule of Europe, Tipula ole- 

 racea, is common in the blades of grass. The 

 common Tipulte^ or Daddy Long-Legs, are 

 well-known examples of this family. Their 

 larva} live in moist ground, and often do great 

 mischief by eating the roots of grass in mead- 

 ows. The IIessian-Fly, Cecidomyia destructor, 

 is noted for its ravages among the wheat crops of 

 this country. Its larvai attack the stems of the 

 plants near the ground, while those of the Wheat- 

 Flt, C. tritici, feed on the flowers, and render 

 them abortive. The ravages of these insects, 

 at particular seasons, have often caused dam- 

 age to the amount of millions of dollars in a 

 single year. 



MOSQUITOS. 



THE (ESTRID^. 



THE MEADOW-TIPULE. 



horses 



This family includes the O ad-Flies and Breeze 

 or Bot Flies, so troublesome to cattle and 

 The Ox-Fly, CEstrus bovis, is three-fourths of an inch long, and lays its eggs in the 



