880 PARKS 



about two days. The wiggletails move vigorously about in the water feed- 

 ing, and gradually increase in size from six to ten days, depending upon 

 the species of the mosquitoes and the temperature of the water. The 

 warmer the weather and the higher the temperature of the water, the more 

 rapid is the development. During all this time the wiggletail is an air- 

 breather. It frequently comes to the surface of the water to breathe, accom- 

 plishing this by holding its breathing tubes, which are at one end of the 

 body, to the surface of the water. 



When the larva has attained its full growth it changes into what is called 

 the pupa. The pupa is also an air-breather, breaking through two small 

 tubes, which project like horns from the top of its head. During the pupal 

 stage no food is taken and it spends its time floating quietly at the surface 

 of the water. At the end of one or two days the skin of the pupa splits and 

 the full-grown mosquito comes forth. The new mosquito floats on the sur- 

 face of the water for a short time until its wings harden and then flies off 

 on its bloodsucking career. About a week is required for the cycle of egg 

 to adult. In another week the female mosquito is ready to start laying 

 eggs, and she will lay two hundred each week after that. 



Only the female mosquito preys upon man. The male is seldom found 

 far from the breeding places. His food consists of plant and vegetable 

 juices, for his boring apparatus is not strong enough to penetrate the human 

 or animal skin. It is only in default of a source of blood supply that the 

 female will live on the thin nourishment that sustains the male. Male 

 and female mosquitoes can easily be distinguished by examining the head. 

 If the antennae and palpi which project from it are very feathery, the 

 mosquito is a male; if they are rather bare, it is a female. 



Mosquitoes must have water in which to spend the wiggletail state of 

 their lives. They do not breed in weeds, grass, trees or vines. They will 

 go into such places for shelter from the sun, wind or rain, but they cannot 

 multiply there. There are many varieties of mosquitoes, but the two that 

 most concern the sanitarian are that species of the Aedes formerly known as 

 the Stegomyia, which is the carrier of yellow fever and dengue fever, and the 

 Anopheles, which is the carrier of malarial fever. The former is domestic 

 and is found chiefly around buildings and breeds only in clear water in 

 artificial containers, such as rain barrels, watering troughs, tubs, wells, etc. 

 The latter is semi-domestic. They breed in natural pools of clear water, 

 particularly those with grassy edges which form a harbor. The Anopheles 

 travels a little farther than the Aedes but very rarely gets more than a 

 half mile from its breeding place. 



In the control of the mosquito menace there are two main lines of 

 attack, namely, eliminating or controlling the breeding places, and screen- 



