INSECTS ATTACKING STORED GRAIN. 51 



change, a hole is gnawed by the larva at the apex of the kernel 

 for the exit of the future moth. This hole is conspicuous, and is 

 the one referred to in the diagnosis as betraying infested grains. 



Kernels of suspected grain should be split open ; if infested by 

 the pest, either a small, white, brown-headed grub, with nine pairs 

 of legs, or a brown, mummy-like pupa, with wing-pads, antennae, 

 and legs closely pressed against the body, will be seen. Or there 

 may be found the perfect moth, with folded wings, ready to emerge 

 from the kernel. 



Remedies. Fortunately effective remedies are at hand for the 

 attacks of these stored-grain pests. In 1879 Dr. C. V. Riley 

 called attention to the use of bi-sulphide of carbon, on a large 

 scale, as an insecticide, and this substance may be effectually used 

 against the Grain Moth. Bi-sulphide of carbon is sold at retail 

 by druggists for about 25 cents a pound, but it may be bought 

 for considerably less when got in larger quantities. It is an ex- 

 tremely volatile liquid, and the insects are killed by its vapor. It 

 is necessary, therefore, that it be so applied that the vapor may 

 penetrate all through the bin of grain. 



The grain to be treated should be in a tight bin. If the grain 

 is not stored in tight bins, such a bin, or box, should be con- 

 structed, and the grain treated in it in successive portions. If 

 the grain is wheat or oats or shelled corn, a long tube, open at 

 both ends, but carrying within it a snugly-fitting rod, should be 

 thrust into the grain until one end of the tube is near the center 

 of the bin. The rod should now be withdrawn, and a quantity 

 of the bi-sulphide of carbon should be poured into the tube. 

 About one ounce of liquid to each 100 pounds of grain in the 

 bin should be used. Finally, the tube should be withdrawn, the 

 liquid being left in the center of the grain mass. 



Another recommended method of applying the insecticide is 

 that of soaking with it a ball of cotton fastened to the end of a 

 pole. The soaked cotton may now be pushed into the grain. 

 Two or three applications of this kind, in different places in the 

 bin, will effectually destroy all insect life in the bin. If the corn 

 is in the ear, a convenient method of application is to pour the 

 bi-sulphide of carbon into small, open dishes, setting these dishes 

 about on the corn ; or, the surface of the stored corn may be 

 sprinkled with the liquid. The fumes of the bi-sulphide are 

 heavier than air, so that they sink down into the bin. &reat 



