October, ’24] 
doane: control of cereal food insects 
553 
reaches a temperature of from 100°F. to 190°F. depending upon the 
coarseness of the material. Such coarse material as flaked wheat and 
rolled oats would require a longer exposure, that is, it would have to 
pass over more plates before the sterilization would be effective, but 
such fine material as corn meal, germea and cereals of that type are 
thoroughly sterilized by this process, all of the stages of the insect in¬ 
cluding the eggs, being destroyed. 
Careful tests made of the material before and after passing over these 
sterilizing plates shows that material with a moisture content of 10.63 
comes from the sterilizer with a moisture content of from 9.23 to 10.10, 
or an average loss of 1.21%. This, of course, is inconsiderable. 
As the material is to be packed soon after it comes from the sterilizer it 
will be best to screen it before it goes on to the first plate, the size of the 
openings of the screen depending upon the material to be sterilized. 
We find that a screen with a mesh .0328 inches in diameter removes all 
of the adult beetles and all but the smallest larvae from such materials 
as corn meal and germea. Anything that passes through this screen is 
so small that its presence can be detected only by the closest kind of 
examination. Unless the material has been standing for sometime 
after it was screened, there is very little chance of its being infested with 
these small larvae. 
Summing up then we may say that the chief advantages of such an 
apparatus as this for sterilizing these cereals is its simplicity, its inex¬ 
pensiveness, the constant temperature which is maintained without any 
attention from the operator, the small amount of moisture that is lost in 
the process, and the fact that the apparatus can be placed in the packing 
room close to the packing table so that the material can be packed in the 
containers immediately after sterilization. Experiments have shown 
that it is perfectly safe to pack the material immediately after it comes 
from the sterilizer. 
Prof. Doane then exhibited a working model of the machine de¬ 
scribed in his paper. 
COTTON BOLL WEEVIL AND THURBERIA BOLLWORM 
PROBLEM IN ARIZONA 
By Chas. T. Vorhies, University of Arizona, Tucson, Ariz. 
Abstract 
The cotton growing valleys of southern Arizona, particularly those about Tucson 
are of great interest to southwestern entomologists because of the presence in the 
