74 



Circular No. 15. 



oil on tne water in buckets and barrels will destroy the yellow 

 fever and brown mosquitoes. Draining swampy ground near 

 dwellings will reduce the numbers of malaria mosquitoes. Oil 

 may sometimes be used on ponds for the latter. Screens on doors 

 and windows are necessary in both city and country if we would 

 enjoy freedom from both mosquitoes and house-flies. The dis- 

 covery that such diseases as typhoid fever and malaria are car- 

 ried by these insects makes these effective barriers almost a 

 necessity. 



When mosquitoes have already gained access to rooms it is 

 sometimes necessary to adopt other measures to get rid of them. 

 Insect powder answers this purpose very well, being effective 

 either when puffed freely into a room, or better, to avoid the 



11. Adult malaria mosquito (A. maculipennis) . Female. Original 



