DESTRUCTION OF MOSQUITOES IN DWELLINGS. 123 



and-siilphiir treatiueut has proved most effective. Other species of 

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

 Nal., E. 'nidis Canest., and E. taxi Murray, with eciually 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. IIkrkeka. 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 l?ECOM:\IEXr)ATIONS. 



(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 they should be scattered with the bellows as high as 

 ])ossible, in various directions, care being taken besides that the}' 

 penetrate under the beds and other ])ieces 'of furniture, beliind the 

 doors, 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 jjowder for 

 every room of 20 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 glass 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 roouL 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. 



(4) To avoid inflainmation of the throa{ the pers(m who has to 

 scatter the powder should cover the mouth and a part of the face with 

 a handkerchief and leave the room as soon as possible. 



1 Boletin de la Coniision do Parasitolosia .Vgrioola, Toiiin TL pag. l.'^O. 



