INSECTS AND HEALTH 



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rest with the body parallel to the surface upon which 

 they touch. 



Among the larvae, or wigglers, these positions are quite 

 reversed, as the malarial kinds are usually found with their 

 bodies just under the surface of the water and parallel to it, 

 while the other kinds hang, head 

 downward, nearly at right angles 

 to the surface (Fig. 177). Green 

 scum is usually present where 

 malarial mosquitoes abound. 



The remedies. These mos- 

 quitoes do not fly far from the 

 places where they breed. It is 

 only necessary to thoroughly 

 screen the houses, to avoid being 

 bitten by the mosquitoes, and to 

 fill or drain the places where they 

 breed to stop completely the spread of this disease. Care 

 should be taken to empty the water at least once a week 

 from drinking troughs, barrels, etc., where the mosquitoes 

 might breed. Tin cans, or similar water holders, should 

 be buried or placed so that they cannot hold water. Cis- 

 terns and wells should be covered and everything possible 

 done to prevent the multiplication of mosquitoes of any 

 kind. The reward for such work will be a largely increased 

 measure of comfort and health. 



NOTE TO THE TEACHER. Bulletins on mosquitoes have been pub- 

 lished especially by the United States Department of Agriculture and 

 the state experiment stations at the following post offices : Berkeley, 

 Cal. ; Lexington, Ky. ; College Park, Md. ; Agricultural College Post 

 Office, Miss., and New Brunswick, N. J. 



FIG. 17.7 WIGGLER OF MALA- 

 RIAL MOSQUITO ABOVE 



