II76 



Rural School Leaflet 



the water in rain barrels, tin cans, ponds, streams, pools — in fact, 

 on the surface of almost any standing body of water, large or small. 

 The masses of eggs are dark brown and look like specks of soot floating 

 on the water. In twenty-four hours to a week, depending on the tempera- 

 ture, the lower end of each egg breaks open and a tiny wriggler — com- 

 monly called " wiggler " — or larval mosquito, (Fig. i, e and f) comes 

 forth into the water. These wrigglers are very active and some of them 

 are constantly wriggling up and down in the water in search of food. 

 When not in motion they rest quietly just beneath the surface, with 

 a long tube on the end of the body projecting a trifle out of the water. 



It is through this tube that 

 the tiny wrigglers draw in a 

 supply of air and keep them- 

 selves from drowning (Fig. i, g). 

 The body hangs head down- 

 ward at an angle of about 45 

 degrees (Fig. 1, g). The 

 wrigglers live in the water for 

 one to three weeks, depending 

 on the temperature and the 

 amount of food. At the end 

 of this time each one changes 

 to what is known as a pupa 

 (Fig. 1, h). The pupa appears 

 to have a large head and a 

 slender tail, and can also wriggle 

 about in the water. It lies 

 quietly, when not disturbed, 



'■€&B*!% 



Pig. 2. — Life story of an Anopheles mosquito: 

 (a) female; (b) antenna of male; (c) eggs; (d) 

 larva, or "wiggler"; (e) larva in feeding position J ust at tne SUrrace. In tour 

 at surface of water; (/) pupa. All enlarged. G r five days the skin of the 

 (Adapted from Howard) . * , ,, 



pupa breaks open along the 



back and the full-grown mosquito crawls out. After drying its wings 

 for a few minutes it flies away in search of some animal from which to 

 suck blood. In the fall the full-grown mosquitoes hide in dark cellars, 

 stables, and other places, where they rest quietly until the following 

 spring. 



Life history of a malarial mosquito. — The Anopheles, or malarial mos- 

 quito, lays its eggs on the surface of standing water also; but each egg 

 is laid separately, so that the eggs are not in masses glued together although 

 several may be close together on the surface and lie there touching one 

 another. The eggs hatch into wrigglers, but the wrigglers of Anopheles 

 lie in a horizontal position just beneath the surface of the water (Fig. 2,e). 



