40 



DIPTERA OF MINNESOTA. 



forming dancing swarms in the air. The larvae are aquatic, and not 

 unlike the larvae of mosquitoes. 



The genus Dixa is widely distributed over the world. Ten spe- 

 cies appear to have been taken in North America, and four species 

 not known in North America occur in Great Britain. 



CULICIDAE or MOSQUITOES. 



Veritably no family among insects offers such peculiarly in- 

 teresting matter for discussion as the present one. The world 

 over mosquitoes are anathematized, not only on account of the dis- 

 comfort caused by their presence, but, and this is far more serious, 

 it has been proven that the bite of certain mosquitoes, under proper 

 conditions, causes malaria, yellow fever, and probably one or more 

 other diseases. Fortunately the knowledge of this evil has shown 

 us how to avoid these diseases in affected localities. 



Fig. 



Mosquito larva and eggs; also a single egg. Greatly enlarged. Lugger. 



This family has become of such economic importance, on account 

 of its disease bearing qualities, that many books are published on it 

 alone. Perhaps the most comprehensive is that of F. V. Theobald, who 

 under the title of "A Monograph of the Culicidae of the World," 

 gives us three volumes of text and plates on this interesting group. 

 Col. George M. Giles, of the British army, has published a thick 

 volume on mosquitoes, and Dr. Howard, Chief of the Entomological 

 Bureau at Washington, has written, and is constantly writing much 

 of economic value of these pests to man. The same may be said 



