vin. D. 1 



Jones: The Cigarette Beetle 



15 



extremely inflammable, a spark of any description, even a lighted 

 cigar or cigarette, may explode the fumes. Electric fans and 

 lights should not be used inside the fumigating compartment, 

 for there is danger of the production of sparks which will ignite 

 the fumes. 



The cigarette beetle in all its stages can readily be killed by 

 carbon bisulphide of the concentration of 14.4 grams per cubic 

 meter in air-tight vessels, where the fumes of carbon bisulphide 

 come in direct contact with the insect. Where there is an abun- 

 dance of tobacco in which the beetles are protected, a greater 

 quantity of carbon bisulphide must be applied. Experiments 

 prove that 32 grams of carbon bisulphide per cubic meter are 

 very effective in the latter case, but in practical work it is recom- 

 mended that slightly more (40 grams) be used in order to insure 

 a satisfactory excess. 



Table YII.— Effect 



of different 



amounts of carbon bisulphide. 



Date. 



Treatment. 



Condition after fumigation. 



Remarks. 



Quantity of 

 CS2 per 

 cubic me- 

 ter. 



i 



B 



Eggs. 



Larvae. 



Pupae. 



Adults. 



< 



■a 

 Q 



1 



< 



i 



a 



6 

 > 



i 



Q 



> 

 < 



i 



Q 



1911. 



Grams. 



Hours. 





















June 23 

 June 26 

 Ausr. 2 



32 



32 



14.5 



36 

 48 

 16 









 

 



116 

 17 

 12 





 

 



13 





 6 





 

 



68 

 18 

 20 



ITobacco fumigated in 

 1 manos. 

 Eggs were fumigated 







20 





























only 6 hours. 



Sept. 13 



24 



24 



2 



337 



33 



167 







10 







50 



Larvje lived and some 

 developed into adults, 

 but did not feed after 

 fumigation. 



Sept. 20 



34 



17 







80 







125 







50 







75 





Table VII shows that the adults and pupse are more susceptible 

 to the gas than are the eggs and larvae. The fumigations dated 

 September 13 and 20, except in the amount applied and the 

 duration of the experiment, were done under identical conditions. 

 All pupae and adults in both were killed. In the experiments 

 of September 13 the larvae appeared to be dead, but on the 

 feecond day some revived; they did not feed; 18 pupated and II 

 emerged, 5 lived until November 16 and then died; the adults 

 laid no eggs. 



