PROJECTS , 633 



them either on their own premises or on adjoining vacant lots. 

 In New Orleans, Havana, the Panama Canal Zone, and many other 

 places, intelligent and concerted effort has eliminated the mosquito 

 as an agent of disease. Any community may accomplish the same 

 thing. 



In order to fight the mosquito intelligently, we must know some- 

 thing of the way the pest comes into the world. When one realizes 

 that one female mosquito lays from 75 to 300 eggs at a time and that 

 these eggs develop into full-grown mosquitoes in from 10 to 13 days, 

 one does not wonder at the clouds of mosquitoes that sometimes 

 infest low swampy places. 



Mosquito eggs are laid at night or in the early morning on the 

 surface of stagnant water. Mosquitoes avoid running water or 

 fresh water that is frequently stirred. In about 24 hours in warm 

 weather or somewhat longer if the temperature is not high 

 the eggs hatch into the larva stage. The larva, or "wiggletail," 

 which almost everyone has seen in stagnant pools or rain barrels, 

 spends most of its time, head downward, just under the surface of 

 the water. It keeps the tip of its tail (where the opening of its 

 breathing tube is located) almost constantly at the surface of the 

 water. In fact, the larva cannot live more than a minute or two if 

 it is unable to reach the surface to breathe. After seven days or more, 

 according to the temperature, the developing mosquito passes from 

 the larva to the pupa stage. After living in the water in the pupa 

 stage for three days or more, it finally emerges as a full-grown mos- 

 quito. 



Mosquitoes do not fly far from the places where they are hatched ; 

 hence, if they can be kept from breeding near human habitations, 

 the problem of mosquito riddance is solved. 



Drainage. Since stagnant water furnishes breeding places for 

 mosquitoes, the first work to be done is to drain all unnecessary 

 ponds or pools. Very often valuable land may be reclaimed by 

 the very process of draining that rids a section of mosquitoes. 



Kerosene. Where it is impracticable to drain pools, puddles, or 

 marshes, the surface of the water may be covered with kerosene. 

 On small pools or tanks it is necessary only to pour the kerosene 



