DESTRUCTION OF MOSQUITOES IX DWELLINGS. 123 



and-sulphur treatment has proved mosl effective. Other species of 

 Eriophyes have been treated with lime and sulphur, viz. E. avellcena 

 Nal., E. rudis Canest., and E. taxi Murray, with equally satisfactory 

 results. 



DESTRUCTION OF MOSQUITOES IN DWELLINGS BY THE POWDERS 

 OF CHRYSANTHEMUM, SPREAD THEREIN BY MEANS OF HAND 

 BELLOWS OR A TOWEL. 



By A. L. Hebeeba, Mexico City, Mexico. 



Ever since 1903 this commission has been commending the destruc- 

 tion of mosquitoes in dwellings by means of the chrysanthemum 

 powders, spread or thrown around therein with hand bellows or a 

 towel. 



ESSENTIAL RECOMMENDATIONS. 



(1) In each room or apartment there should be spread daily, half 

 an hour or an hour before bedtime, the genuine chrysanthemum pow- 

 ders, by means of some hand bellows, cloth, or towel. 



(2) The powders should be spread uniformly in the whole room. 

 and to that effect the}' should be scattered with the bellows as high as 

 possible, in various directions, care being taken besides that they 

 penetrate under the beds and other pieces of furniture, behind the 

 dour-, etc. In case a towel is used, it should be shaken around in a 

 very lively manner and for some time. Some people are wont to 

 place the powders upon a table or a piece of pasteboard and blow said 

 powders upwardly, and at once shake a bed sheet or a towel in the 

 center of the room. 



(3) It is convenient to employ a large spoonful of powder for 

 every room of l ; to 30 cubic meters, and a larger quantity for larger 

 apartments. 



In order to find out whether the quantity of powder that has been 

 used is sufficient, it will suffice to spread some bed sheets upon the 

 floor, so that the mosquitoes may fall upon them. Some of the insects 

 should then be kept under a gla>< to see, on the next day. if they are 

 really dead. Should it not be so. or should no mosquito fall upon the 

 sheets, after an hour, even though they should be in great numbers in 

 the room, the quantity of powder scattered should be increased or a 

 new lot should be bought in another drug store. The same should be 

 done when the insects have only fallen into lethargy at the beginning 

 of the night, and again become troublesome in the morning. 



i I) To avoid inflammation of the throat the person who has to 

 scatter the powder should cover the mouth and a part o\' the face with 

 a handkerchief and leave the room a- soon a- possible. 



"Boletin de la Comisi6n de Parasitologfa Agricola, Tomo 11. pag. 139. 



