VIU, D, 1 



Jones: The Cigarette Beetle 



21 



Table XI. — Effect of different amounts of hydrocyanic-acid gas. 



Date. 



Treatment. 



Stagres of insects. 



Remarks. 



Quantity of 

 KCN per 

 cubic meter. 



i 



a 



ESKS. 



T^arvae. 



Pups. 



Adults. 



1 



> 

 < 



1 



i 



1 



a 



V 



< 



t 

 Q 



> 

 < 



July 29 



August 2 



Augusts 



August 6 - 



September 14.. 

 September 16.. 

 November 29 .. 



Grama. 

 36 

 28 

 32 

 30 



10 

 30 

 10 



Hours. 

 22 

 24 

 13 

 24 



18 



24 

 40 



20 



29 



20 



200 



49 

 306 





 1 

 

 



3 



















Ekks removed 



from leaf. 

 jEgKS fumigated in 

 1 leaf tobacco. 

 Eggs fumigated 

 where adults 

 had laid them; 

 they were well 

 covered with 

 other tobacco. 







































106 



94 



4 



27 



46 



16 











66 



4 















In a recent circular of the Bureau of Agriculture of the Phil- 

 ippines,^^ a dose of 9 grams of potassium cyanide per cubic meter 

 was recommended as sufficient for killing this insect. In former 

 experiments I had found that 28 grams per cubic meter were 

 insufficient for killing the eggs, but for further confirmation 

 I carried on several experiments with the amount recommended 

 with the results shown in Table XII. 



Table XII. — Showing effect of hydrocyanic-acid gas liberated from 9 grams 

 potassium cyanide per cubic m,eter. 



Date. 



Length 

 of treat- 

 ment. 



Stage of insect. 



Remarks. 



Eggs. 



Adults. 



Alive. 



Dead. 



Alive. 



Dead. 



November 14. 

 November 18. 

 November 20. 

 November 21. 

 November 23. 



November 24. 



November 25 



Hours. 

 24 

 48 

 12 

 36 

 24 



24 



96 







13 

 

 

 



67 



105 



25 



50 



Adults in tobacco. 



Adults exposed directly to fumes. 



Eggs on tobacco leaf where they had been 



laid. 

 Adults allowed to get into manos of 



tobacco. 

 Adults, fumigated in manos of tobacco. 

 Fumigated with tobacco. 















10 



10 



280 



212 



16 



332 



182 

 234 







November 25. 



24 



30 20 



In no case, where tobacco was present, was the treatment 

 with 9 grams of potassium cyanide per cubic meter effective, 

 but in a glass jar, where adults were confined in a very small 

 space and exposed directly to the fumes, it was effective. The 



The Cigarette Beetle. Cir. P. I. Bur. Agr. (1912), 5. 



