130 PRINCIPAL HOUSEHOLD INSECTS. 



The vegetable foods most subject to injury are prepared cereals. If 

 any of these be badly infested at the time of purchase it will be plainly 

 evident; if only a moderate number of insects be present and it be 

 desirable to store the material for some length of time, by sifting over 

 a large sheet of paper of light color, using a fine sieve for flour and 

 corn meal and a coarser one for cracked wheat and like foods, the pres- 

 ence of infesting insects may be detected. 



After what has been said regarding the development of the flour 

 beetles and other insects it should be superfluous to add that it is 

 impossible to entirely free infested material by sifting, as the eggs and 

 younger larvae slip through the finest meshes. Most insects may be 

 destroyed by placing the material infested in the oven at a moderate 

 degree of heat, from 125° to 150° F., but care must be exercised not to 

 expose it to a higher temperature. Corn meal, particularly, is easily 

 overheated, and afterwards, unless it is soon to be used in cooking, is 

 apt to become rancid. 



If a barrel of flour or large quantity of other provisions becomes 

 infested, as is apt to happen during the absence of a family from home, 

 bisulphide of carbon, a liquid chemical in general use against insects 

 in mills, elevators, granaries, and warehouses, should be used to dis- 

 infect it. The same reagent is the best insecticide for use when whole 

 rooms are to be fumigated. 



A small quantity of the chemical is sufficient for the disinfection of a 

 barrel of flour, as the insects for the most part live only in the flour at 

 the top, being unable to withstand the pressure of a large weight of 

 material. From a half to a whole teacupful (about 2 to 5 ounces) of 

 the bisulphide will prove sufficient for the purpose in an ordinary case, 

 provided the cover be replaced as tightly as possible. In more severe 

 cases of infestation it may be necessary to repeat the application. The 

 bisulphide is poured into shallow pans or plates placed upon the top of 

 the infested mass and the receptacle covered as closely as possible and 

 left for a day or more. This chemical is extremely volatile, and being 

 heavier than air, descends as a gas, killing such insects as the material 

 may contain. When an entire room or building is overrun with insects, 

 the bisulphide is evaporated at the rate of a pound to every 1,000 feet 

 of cubic space. 



The vapor of this chemical is deadly to all animal life, but there is 

 no danger in inhaling a small quantity, and although it has a powerful 

 and disagreeable odor, this soon passes away without any after effects 

 and without harming for food such material as it may be used upon. 

 The vapor is also inflammable, but if no fire, as, for example, a lighted 

 cigar, be brought into the immediate vicinity until the fumes have 

 entirely disappeared, no trouble will be experienced. 



Bisulphide of carbon costs, at retail, from 20 to 30 cents a pound; at 

 wholesale, in 50-pound cans, 10 cents a pound. 



