MOSQUITOES IN GENERAL 5 



mig"lit have been reared. 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 wig-giers of virgin birth. 



How Long can the Larvae Live Under Water? 



In observations which I have made upon mosquito 

 larvse of the g-enus 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 larvae of 

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

 Although the larvae 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 larvae may stay below for a longer period than I 

 have observed. In the Fmtomological 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 Culex pungens 

 which had been taken in ice, remained under water for 

 fifteen minutes and more. 



