Immature stages of the yellow-fever mosquito: Egg and pupa, or tumbler (left); 

 larva, or wiggler (right). Greatly enlarged. 



Newly hatched wigglers are very light in color and so small that they 

 are not easily seen. They are rather active, moving jerkily to the bottom 

 of the container and then back to the water surface for air. They become 

 full grown in 6 to 8 days, and are then about one-third of an inch long. 

 After about 2 days in the inactive pupal, or tumbler, stage, the adult 

 mosquitoes emerge. 



