THE CANADIAN ENTOMOLOGIST. 235 



completing its growih the catcrpiliar spins a tliin silken cocoon, and 

 within this changes to a brownish pupa; in a few days later the moth 

 emerges. The perfect insect resembles somewhat a clothes moth. The 

 wings expand about half an inch, are of a satiny cream colour and bear 

 a few dark spots on the fore wings, which are narrow, pointed and fringed. 

 The hind wings are darker and have much wider fringes. 



Remedies. — When stored grain is found to be infested by one of the 

 above three insects, or, in fact, by any insects which are known to work in 

 dry cereals, it is a sinii)le matter to destroy them. After repeated experi- 

 ments, it has been found that the use of bisulphide of carbon will kill all 

 the insects without any injury to the grain as to its wholesomeness for 

 food, or as to its germinating quality for seed. Bisulphide of carbon is a 

 colorless liquid with a very ol)jectionable odour, which vaporizes quickly" 

 at the ordinary temperature of the atmosphere. A convenient method for 

 treating small quantities of infested grain, is to fill an ordinary coal-oil 

 barrel, which will hold about five bushels of grain, and the quantity of 

 bisulphide to use is one ounce to every hundred pounds of seed. The 

 bisulphide may be poured right on to the grain or placed in a shallow 

 receptacle, but care must be taken to close up the top of the banel tightly. 

 This is best done with a cap made specially for the purpose, but may also 

 be done with fine sacks laid smoothly on the top, over which boards are 

 laid, with a considerable weight on them to hold the covering down close- 

 ly. When grain in bins is being fumigated with bisulphide of carbon, these 

 should be made as neaily air-tight as possible. This may be done by 

 pasting sheets of paper over the outside, or by covering them with 

 blankets br canvas. In tight bins the amount of bisulphide to use is a 

 pound to a pound and a half to the ton of grain. Some entomologists 

 claim that one pound of bisulphide to every loo bushels of grain is 

 sufficient to destroy all insects, even in open bins. Infested grain should 

 be subjected to the fumes of bisulphide of carbon for at least 48 hours, 

 but as the vapour is very inflammable, no light of any kind must be 

 brought near and no smoking must be allowed near the building when 

 this chemical is being used. 



In Queensland it has been found that salt (i quart dissolved in 2 

 gallons of water) will prevent weevils from attacking grain which has been 

 sprinkled with this solution. 



