INSECTS AND DISEASES 401 



The remedies that man may use may be divided into two 

 groups: first, those directed against the adult stage, and 

 second, those directed against the water stages. 



Remedies against Adults. Fumigants. Against the adults, 

 three measures may be taken : fumigants may be used to 

 kill them ; repellants may be used to drive them away, and 

 screens may be used to keep them out. The mosquitoes 

 in the house may be killed by burning pyrethrum powder. 

 This may be burned completely or heated on a shovel or tin 

 pan. During the process the windows should be closed. 

 The mosquitoes are overcome by the fumes and fall to the 

 floor, where they may be swept up. Burning sulfur is very 

 effective and is often used in fumigating houses which may 

 contain disease-bearing mosquitoes. Special caution how- 

 ever must be taken in its use, as it injures certain household 

 goods. 



Repellants. To prevent mosquitoes from biting, certain 

 substances may be used, the odor of which is unpleasant 

 to mosquitoes. The best of these repellants is oil of citron- 

 ella. This may be applied to the face and hands, or it may 

 be placed on a cloth kept near one, as in sleeping rooms. 

 When applied to the face, care must be taken that none 

 enters the eye, as it causes intense smarting. Citronella 

 may be used alone or with something else. Dr. Howard 

 considers the following the most efficacious mixture that 

 he has tried : One ounce of citronella, one ounce of spirits 

 of camphor, and one half ounce oil of cedar. The effects 

 of the citronella last about an hour. To retard the evapora- 

 tion of the oil, four ounces of vaseline may be mixed with 

 one ounce of oil. 



One of the best remedies for the irritation produced by 

 mosquito bites is moist soap. Other remedies which have 

 been tried and found efficient are glycerine, ammonia, alcohol, 

 or marking the puncture with naphthaline moth balls, indigo, 

 or iodin. 



2D 



