1906.] Destructive Insects in Timber. 621 



as will permit of the seed being abstracted. This seed should 

 without delay be fumigated with bisulphide of carbon. The 

 method is as follows : — Place the material to be treated in an 

 air-tight receptacle. Pour the bisulphide of carbon into a 

 saucer or saucers or other shallow dish, and lay these on the top 

 of the material. Close the receptacle. The bisulphide of car- 

 bon vaporises, and as its fumes are heavier than air they sink 

 down through the material. The receptacle should be kept 

 closed for forty-eight hours. One ounce of bisulphide of carbon 

 will do for 100 lb. of seed, or 1 oz. for every 50 cubic feet 

 of air space. The treatment should be administered in not too 

 cold a temperature. Bisulphide of carbon fumes being poison- 

 ous should not be inhaled by the operator, nor should a light of 

 any kind be brought near. 



If it is desired to store the cones during winter, or longer, 

 these must be similarly fumigated directly they are gathered. 



The results to be looked for from this fumigation with bi- 

 sulphide of carbon are : — 



1st. The germinative capacity of healthy uninfested seeds is 

 not interfered with. 



2nd. In infested seed where the larvae may not have made 

 much progress in destruction of the reserve in the seed, the 

 larvae will be killed and the seed may germinate. 



3rd. In seeds infested, where the contents have been altogether 

 or much destroyed, and which would therefore not have ger- 

 minated, the enclosed larvae will be killed, and the issue of the 

 next year's generation of adults prevented. 



The light seed blown through by the fan at cleaning time 

 should be burnt at once, as where there has been attack this 

 will probably account for many of the pests. 



R. Stewart MacDougall. 



An instance of serious injury being caused to stored timber, 

 especially mahogany and walnut, has recently come under the 

 notice of the Board. The injury was 

 Destructive caused by the destructive beetle, Lyctus 



Insects 

 in Timber. 



canaliculatus. 



Life History — The life history of this 

 beetle may be thus described. The beetle chooses as its favourite 



