308 



APPLIED ENTOMOLOGY 



are marked with dark spots. In alighting on an object, the body is 

 tipped at quite an angle to the object on which it rests (Fig. 325) and 

 these two differences will at once serve to distinguish the malarial mosqui- 

 toes from other species. Another distinction is in the length of the palpi 

 of the female which in the House Mosquito are short, while in the Malarial 

 Mosquito they are as long as the beak and therefore quite noticeable. 

 The species of Anopheles named above is found from Canada to 

 Mexico, east of the Rocky Mountains. 



FIG. 326. FIG. 327. 



FIG. 326. Female Malarial Mosquito (Anopheles punctipennis Say) much enlarged. 

 Antenna of male at right. (From U. S. D. A. Div. Ent. Bull. 25, n. s.) 



FIG. 327. Larva of Malarial Mosq.uito, greatly enlarged. (After Howard, Dyar 

 and Knob.} 



Winter is passed as the adult, and the eggs are laid singly on the 

 surface of water and hatch 2 or 3 days later. The larvae (Fig. 327) 

 resemble those of the House Mosquito but have a shorter respiratory 

 tube and lie horizontally just below the surface instead of hanging head 

 downward. (Fig. 321). The larval period is about 2 weeks, followed by 

 a pupal stage lasting 2 or 3 days. Accordingly, a new generation of 

 these mosquitoes may appear about every 3 weeks. 



Most species of Anopheles attack man chiefly during the twilight 

 and early morning hours. The various species of Culex seek their food 

 at night though often beginning their work late in the afternoon. 



