DESTRUCTION OF FLY LARViE IN HORSE MANURE. 



15 



Table II. — Destruction of fly larvae in horse manure — Results with partially 

 effective larvicides — Cage experiments at Arlington, Va., summer of 1913. 



No. 



Series C: 

 1.... 



4.... 



Series D: 

 1.... 

 o 



4.... 



5.... 



Series E: 



1.... 



Treatment of 8 bushels 

 of manure; 10 gallons 

 used whenever solu- 

 tion was applied. 



Potassium cyanid, 0.1 

 per cent solution. 



Potassium cyanid, 0.02 

 per cent solution. 



Potassium cyanid. 0.004 

 per cent solution. 



Control (water only) 



Paris green, 1-20 



Paris green, 1-40 



Paris green, 1-80 



Control (water only). 

 do 



Formaldehyde, 1 1-3 solu- 

 tion. 



Formaldehyde, 1-6 solu- 

 tion. 



Formaldehyde, 1-12 solu- 

 tion. 



Control (water only) 



do 



.do. 



Larval mor- 

 tality, 1 

 quart sam- 

 ple of ma- 

 nure 2 days 

 after treat- 

 ment. 



Alive. Dead 



Num- 

 ber. 

 82 



86 



251 



1,287 



92 

 35 

 32 

 322 

 298 



27 



L46 



102 



76 



Per 



cent. 

 93.6 



93.3 



80.6 







70.3 



88.7 

 89.7 











81.5 



85.2 



75 





 

 



Num- 

 ber. 



100 



350 



400 



Few. 



Few. 



Few. 



100 



30 



1 



22 







15 

 127 

 221 



°o 



si 



ft-9 



o PI 



n 



Mil- 

 lions. 

 5,250 



7,260 



7, 620 



6, 130 



1,740 

 7.300 

 19,950 

 3,060 

 4,800 



14 



5,200 

 6, 000 

 5,100 



Per 



cent. 

 0.68 



1.00 



.63 



1.12 



.70 

 .59 

 .56 



. 55 



.72 



.58 



.46 



.60 



.84 

 .68 

 .65 



Water extract. 



In per cent 

 of total 

 nitrogen . 



°a 



W bo 



Per 



cent. 

 19.85 



23.60 



20.48 



24.11 



13.43 

 22. 88 

 25. 00 

 23. 45 

 21.11 



18.97 



21.74 



18.33 



26.19 

 25.00 

 18.46 



[ft w© 



Is 111 



8 rSftS 



Per 

 cent. 

 3.09 



2.90 



Trace, 



3.57 



2.71 

 1.86 

 4.64 

 2.55 

 2.08 



3.62 



4.57 



2.83 



2.62 

 3.09 

 2.46 



C. c. 

 10.25 



14.50 



10.00 



17.65 



9.00 

 7.50 

 6.00 



7.75 

 7.50 



.75 



2.00 



10.50 

 6.50 

 5.00 



i Nitrites and nitrates were found in Nos. 1, 2, and 3, Series E. 

 SODIUM FLUORID. 



Sodium fluorid was used in two cage experiments. In one it was 

 applied at the rate of 2 pounds per gallon, and 454 flies developed. 

 In the other 1 pound per gallon was used, and 1,053 flies developed. 

 From the two control cages the totals were 6,152 and 5,870. Thus 

 the stronger concentration destroyed over 90 per cent of the maggots, 

 and the weaker strength 84 per cent. No open piles were treated. 



No bacteriological or chemical analyses were made of the manure 

 treated with sodium fluorid. From the limited number of tests with 

 this chemical, it is evident that it may possess some value as a larvi- 

 cide, and further experiments will be conducted, using commercial 

 sodium fluorid, although the cost (5 pounds, $1) may prohibit its 

 general use. 



AMMON1ACAL GAS LIQUOR. 



Ammoniacal gas liquor, which is a by-product of the manufacture 

 of illuminating gas, evidenced some larvicidal effect when 

 used in the strengths of 1-5 and 1-25. From the cage treated with 

 the stronger dosage 206 flies were caught and 179 flies from the 



