30 



INJURIOUS INSECTS OF 1904. 



work arrange to alternate the extremely cold temperature with warm, that is, 

 after the first exposure to cold for a few days, allow the mill to become warm 

 and follow this with another cold exposure. Repeat the operation two weeks 

 later. The above lots, Nos. i to 6, were masses of matted flour containing the 

 worms, the latter being thus somewhat protected. 



The Entomologist also tried the following experiments: 



EGG. 



Efifect of 

 exposure to 

 fumes of 

 Carbon 

 bisulphide. 



Efifect of 

 exposure to 

 fumes of 

 Carbon 

 bisulphide. 



'Exposure to fumes of CSs 



Exposure to fumes of CS.: 



Exposure to fumes of CSu 



Exposure to fumes of CS2 



(i part liquid CS2 to loooo 

 parts atmosphere) for 42 

 hours failed to kill eggs. 



(i part liquid CS2 to looo 

 parts atmosphere) for 42 

 hours failed to kill eggs. 



(I part liquid CS2 to 5000 

 parts atmosphere) for 6 

 hours failed to kill eggs. 



(i part liquid CS- to 5000 

 parts atmosphere) for 12 

 hours failed to kill eggs. 



'"Exposure to fumes of CS2 (i part liquid CS2 to 5000 



parts atmosphere) for 24 

 hours failed to kill eggs. 



65^ days' exposure to 12 degrees above zero did not kill all 



the eggs. 

 63/$ days' exposure to 3 to 5 degrees above zero killed all 



eggs. 

 36 hours' exposure to 3 to 5 degrees above zero killed all 



eggs. 

 36 hours' exposure to 3 to 5 degrees above zero failed to 



kill all the eggs. 



These eggs were kept under observation for two to three weeks. In every 

 case control sets were preserved. 



Efifect of Low 

 Temperature. 



LARV^ 

 or "Worms." 



Efifect of 

 exposure to 

 fumes of 

 Carbon 

 bisulphide. 



Effect of Low 

 Temperature. 



"Exposure to fumes of CS2 (1-5000) for 24 hours killed 



larvae. 

 Exposure to fumes of CS2 (i-ioooo) for 42 hours killed 



larvae. 



6y2 days' exposure to 3 to 5 degrees above zero killed larvae. 

 6y2 days' exposure to 12 degrees above zero killed larvae. 

 36 hours' exposure to 3 to 5 degrees above zero ("worms" 

 just hatching) killed larvae. 



Newly hatched larvae will live from two to three days without food. 



