1C) PROC. ENT. SOC. WASH., VOL. 21, NO. I, JAN., 1919 



Experiments with Kerosene, 44 Baume. 



Temperature of Number of Age at Number Percentage 



Treatment. oil. eggs. treatment, hatched hatched. 



Immersed for 

 period of 



2 minutes 25 C. 195 5-7 days 1 0.51', 



2 minutes.. 25 C. 330 5-7 days 43 13.0', 



5 minutes.. 25 C. 87 5-7 days 



5 minutes 25 C. 255 5-7 days 3 1.17', 



10 minutes. . 25 C. 235 5-7 days 



15 minutes... 25 C. 138 5-7 days 



15 minutes 25 C. 550 5-7 days 



15 minutes . 25 C. 360 1-3 days 



30 minutes.. 26 C. 85 4-6 days 



45 minutes... 26 C. 175 4-6 days 



1 hour. 26 C. 105 4-6 days 



H/2 hours 26 C. ca. 280 4-6 days 



The above series of oils are .discussed in the order of increasing 

 specific gravity but it must not be inferred that there is any 

 relation between the specific gravity and ovicidal properties. 1 

 A sample of benzol was used which was heavier than kerosene, 

 having a specific gravity of 30.5 Baume. The following experi- 

 ments indicate that it does not act as quickly as the 52 Baume 

 gasoline-kerosene mixture : 



Experiments with Benzol. 



Temperature Number of Age at Number Percentage 



Treatment. of oil. eggs. treatment hatched. hatched. 



Immersed for 

 period of 



15 minutes 23. 5 C. ca. 125 0-4 days 66 52. S' , 



30 minutes.. 23. 5 C. ca. 200 0-4 days 127 63.5', 



45 minutes.. 23.5C. ca. 250 0-4 days 238 95. L", 



1 hour. 23. 5 C. ca. 200 0-4 days 50 25 .<)' , 



2 hours.. 23. 5 C. ca. 260 5-7 days 

 4 hours... 23.5C. ca. 350 5-7 days 



Further experiments with this oil are necessary before any 

 definite statement can be made. If it is effective against eggs of 



1 The Baume scale is used in the trade. The more scientific specific 

 gravity equivalents for the Baume degrees mentioned in this paper are as 

 follows: 



30.5 Baume .... .... 0.875s g 



44 ... SOD s. g. 



48 . . 0.7i'2 s. g. 



52 ... 0.775s. g. 



56 0.75S s g 



60 . 0.74:! s. g. 



