ELIMINATION FROM BUILDINGS 457 



In camps which are not mosquito proof, tlie onh- effective 

 means of obtaining comfort is by the use of smudges as described 

 for blackflies (p. 484). 



Protection of houses against mosquitoes is almost a necessity 

 in many places. To a certain extent the construction of a house 

 affects the number of mosquitoes attracted to it. Light, airy 

 rooms with white walls are much less infested with mosquitoes 

 than are dark, damp houses. Ross says that houses decorated 

 with curtains, pictures, stuffed chairs and similar " barbarous " 

 furnishings are entirely inappropriate for the tropics, and he 

 deplores especially the use of curtains since they " check the 

 breeze which is so cooling to the inmates and so unpleasant for 

 mosquitoes." 



The careful screening of houses or rooms is highly valuable, 

 especially in places where mosquito-borne diseases are prevalent. 

 Mosquito net or screen should never be less than 18 meshes to 

 the inch. Cloth net is more effective than wire, since mos- 

 quitoes cannot as readily force their way through, but nets with 

 thin threads should be used and should be stretched tightly in 

 order not to exclude the breeze in hot weather. The use of tight 

 canopies over beds is extensively practiced in southern United 

 States, especially in malarial districts, and these are very com- 

 mendable when kept in good repair. Most firms dealing in camp 

 outfits place on the market light folding frames covered with 

 mosquito netting for use when resting or sleeping out of doors 

 in mosquito-infested places. 



Usually a few mosquitoes find their way into screened rooms 

 in spite of the screens, through unnoticed crevices, opening of 

 doors and the like. These can usually be discovered and des- 

 troyed with a fly spanker, or, what is just as effective in case 

 spotting the walls with blood is to be avoided, by holding a cup 

 of kerosene directly under them. The mosquitoes are stunned 

 by the vapor and fall into the cup in a few seconds. Mosquito 

 traps have been found useful in some places, these contrivances 

 consisting merely of a box, dark colored inside, placed where it 

 will readily be found by mosquitoes and utilized as a hiding 

 place. The box is arranged so that the insects do not readily 

 find their way out and so that it can be fumigated easily. 



Larvicides. — Far more effective and satisfactory in every 

 way as a method of coping with mosquitoes is their actual ex- 



