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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
Table 3. Effect of Mixing Milltown Ball Clay No. 9 (200 mesh) with 
Common White Beans in Various Proportions and Seeding Each Group with 
25 Adult Bean Weevils. Temperature 80° F. and Humidity 73.4% 
(Nov. & Dec. 1921) 
Composition of the mixture No. of Beans No. infested No. of Holes 
Parts of Clay 
Parts of Beans 
by weight 
by weight 
1 
1 
440 
0 
0 
1 
5 
446 
0 
0 
1 
10 
424 
0 
0 
1 
15 
440 
4 
17 
1 
20 
430 
9 
27 
1 
30 
436 
8 
23 
1 
40 
438 
9 
22 
1 
50 
432 
13 
32 
1 
70 
427 
16 
36 
1 
90 
434 
12 
17 
1 
100 
440 
18 
30 
Check 
426 
86 
86 
Thus it appears that this clay affords complete protection when used 
at the rate of 1 part of clay to 10 parts of beans by weight. 
In an effort to see what effect this clay would have against the 
angoumois grain moth (,Sitotroga cerealella) on corn and wheat, mixtures 
of it and these grains were made. An ear of corn was rotated in the 
clay dust, placed in a jar and subjected to infestation by several pairs of 
moths. In due time a reasonably heavy infestation resulted. 
Shelled com was then tried and the results are shown in table 4. 
Table 4. Effect of Mixing Milltown Ball Clay No. 9 (200 mesh) in Varying 
Proportions with shelled, Yellow Dent Corn. Temperature 80° F. and 
Humidity 73.4% (1922) 
Composition of 
Period in 
No. of 
No. of 
No. of 
No. of 
Mixture 
days from 
moths 
moths 
corn 
corn 
Parts of 
Parts of 
introduc¬ 
introduced 
at end 
grains 
grains 
clay by 
corn by 
tion to 
infested 
weight 
weight 
exam. 
1 
1 
29 
4 
4 
153 
0 
1 
5 
26 
4 
4 
160 
0 
1 
10 
24 
4 
4 
149 
0 
1 
15 
32 
4 
4 
154 
0 
1 
20 
32 
4 
4 
154 
0 
1 
30 
36 
2 
2 
148 
0 
1 
40 
36 
2 
2 
149 
0 
1 
50 
32 
2 
2 
152 
0 
Check 
40 
2 
68 
150 
68 
Thus it appears that Milltown Ball Clay No. 9 affords protection to 
shelled corn when mixed with the corn at the rate of one part of the 
