MOSQUITOES m GENERAL 5 



might have been rearecT. Professor Kellogg's observa- 

 tion indicates plainly that interesting studies can be 

 made with mosquitoes in this direction, and it will be 

 especially interesting- to observe the sex of the adults 

 reared from wigglers of virgin birth. 



How Long can the Larvae Live Under Water? 



In observations which I have made upon mosquito 

 larva? of the genus Culex, I have been unable to time 

 them below the surface for more than two minutes. As a 

 rule they return to the surface to breathe after the expi- 

 ration of not more than a minute. With the larv?e of 

 Anopheles, as will be shown later, the case is different. 

 Although the larvge remain at the surface of the water 

 during the early part of their lives, when they become 

 full grown they will descend to the bottom and mouth 

 over the slimy grains of sand or water-plants which are to 

 be found there. In this operation they have been timed 

 by one of my assistants, Miss Sullivan, and remained 

 ten minutes before ascending for air. It seems also, 

 from observations made by Dr. John B. Smith, that even 

 Culex larvse may stay below for a longer period than I 

 have observed. In the Entomological News for March, 

 1901, he states that he has timed them under water for as 

 long a period as ten minutes, and in a later publication 

 states that these same larvae which were CuJex pungens 

 which had been taken in ice, remained under water for 

 fifteen minutes and more. 



