292 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 17 
Table I. Results of the Naphthalene Whitewash Treatments, Cottage Farm, 
Salem, Oregon, 1922 
Applications made June 21. Results noted December 1. 
Treatments Results 
Num- Num- Trees Infested Number of 
Method of ber of ber of Num- Per Worms 
Formula 
Application 
trees 
Aees 
ber 
cent. 
Total 
Per 
1.22 Naphthalene 
Paper collar 
t eated wormed 
14 8 3 
37 
4 
tree 
.50 
1.2 s 
Protective wash 
14 
8 
2 
25 
4 
.50 
1.22 
Soil not removed. 
Cotton band at base 
14 
8 
3 
37 
12 
1.50 
2.22 Naphthalene: 
Paraffine 1:12 lbs. 
Paper collar 
14 
8 
2 
25 
3 
.37 
2.22 
Protective wash 
15 
8 
0 
0 
0 
0 
3.22 Naphthalene 
Paraffine 2:1 \y 2 lbs. 
Paper collar 
14 
7 
2 
28 
4 
.57 
4.22 Naphthalene: 
Paraffine 3:1 21 oz. 
do 
14 
7 
2 
28 
3 
.43 
4,22 
Pro ective wash 
15 
8 
2 
25 
2 
.25 
4.22 
So l not removed 
Cotton band 
15 
8 
5 
62 
10 
1.25 
5.22 Naphthalene: 
Paraffine 2:1 1 lb. 
Protectiv was 
15 
8 
2 
25 
2 
25 
6.22 Naphthalene: 
Paraffine 3:1 1 lb. 
do 
14 
2 
2 • 
2 
25 
7.2 ' Naphthal ne: 
Parowax 3:1 1 lb. 
Paper collar 
15 
8 
37 
4 
50 
Checks —no treatment 
34 
2 
4 
.CO 
Results as shown in table 1 indicate a general reduction of infestation 
in the treated plots as compared with the checks. The best results 
were obtained with formula 2-22 used in connection with a protective 
wash at the bases of the trees. In the plots where the soil was not 
removed from about the trees, and the wash was applied over a cotton 
batting band placed around the trunk at the soil level, the results were 
unsatisfactory. The paper collars reduced the efficacy of the washes 
slightly, the treatments being more effective when used with a protective 
wash at the base of the tree. The mixtures of naphthalene and paraffine 
proved more effective than the napthalene alone. 
No injury to the trees was detected where the washes were applied 
in connection with paper collars or the protective wash. 
Paradichlorobenzene 
Paradichlorobenzene was applied to prune trees at Creswell, Corvallis, 
and Salem. The applications of this material were made according 
