June, ’24] 
graham: temperature and subcortical insects 
381 
upper side of white pine logs exposed to full sunlight except in the case of 
a few very thick barked logs. On the other hand, Chrysobothris dentipes 
with its much higher fatal temperature would find conditions satis¬ 
factory for its development on the upper side of many logs lying in the 
sun. We might also expect to find that the cooling effect of dense shade, 
although it might not be in itself fatal, would so reduce the rate of de¬ 
velopment of the insect inhabitants of logs placed in such situations that 
higher mortality than normal of the insects within the logs would result. 
That these theoretical deductions are in general correct is shown in 
Table V. In this table the actual distribution of these three species is 
illustrated. 
Table V. Distribution of Subcortical Insects under Different Conditions 1 
Ips pini Say 
Top side 
West side 
Degree of shade 
Degree of shade 
Species 
0 
1/3 
1/2 
3/4 
Full 
0 
1/3 
1/2 
3/4 
Full 
White pine.. . . 
1.1 
40.2 
77.1 
131.4 
42.1 
67.4 
56.1 
98.8 
91.8 
50.0 
Jack pine. 
0.4 
9.2 
33.5 
64.4 
21.6 
21.7 
36.1 
43.7 
33.6 
23.5 
Norway pine. . 
73.4 
69.4 
164.2 
125.9 
41.5 
86.5 
60.0 
99.0 
84.4 
37.5 
Monochamus scutellatus 
White pine.. . . 
0.5 
2.0 
5.2 
2.2 
6.7 
7.0 
10.5 
6.0 
Jack pine. 
1.6 
0 
1.3 
0.6 
2.6 
4.3 
1.3 
2.0 
Norway pine. . 
1.0 
1.0 
0.6 
1.0 
4.0 
2.0 
3.0 
3.0 
Chrysobothris dentipes 
White pine.. . . 
19.7 
17.2 
2.5 
0 
0 
2.7 
0.2 
0 
0 
0 
Jack pine. 
17.0 
5.0 
0.6 
0 
0 
0 
0 
0 
0 
0 
Norway pine. . 
12.0 
1.0 
0.3 
0 
0 
0 
0 
0 
0 
0 
Ips pini Say 
East side 
Bottom side 
Degree of shade 
Degree of shade 
0 
1/3 
1/2 
3/4 
Full 
0 
1/3 
1/2 
3/4 
Full 
White pine.. . . 
69.9 
74.9 
90.5 
64.0 
39.3 
23.3 
21.2 
23.1 
23.2 
38.5 
Jack pine. 
39.7 
48.0 
63.1 
33.9 
27.0 
17.4 
19.3 
12.5 
14.7 
19.6 
Norway pine. . 
80.6 
59.3 
95.1 
81.5 
42.1 
40.0 
16.5 
31.4 
35.8 
44.1 
Monochamus scutellatus 
White pine.. . . 
5.2 
4.5 
11.2 
4.5 
5.5 
4.2 
11.6 
2.2 
Jack pine. 
1.3 
4.0 
1.3 
0.3 
3.0 
2.3 
2.3 
1.0 
Norway pine. . 
1.3 
1.6 
4.3 
1.3 
4.6 
3.3 
1.3 
2.0 
Chrysobothris dentipes 
White pine.. . . 
4.0 
2.5 
0 
0 
0 
0 
0 
0 
0 
0 
J ack pine. 
3.0 
0.6 
0 
0 
0 
0 
0 
0 
0 
0 
Norway pine. . 
0.3 
0 
0 
0 
0 
0 
0 
0 
0 
0 
^ata presented in this table represents the number of insects present per unit area 
of one square foot. 
