Part III.] Beeson: Beehole Borer of Teak. 
67 
2. Results of Analyses. 
Number of Trees Analysed=19. Bate of Analysis 3rd-8th June, 1919. 
Table 13. — Girth-Beehole Incidence in a 22-year-old Plantation , Petsut 
Reserve, Katha, 1919. 
3-inch 
Serial 
Girth in 
Number of 
Arithmetic 
Arithmetic 
Girth-Class. 
Number of 
Inches. 
Beeholes. 
Mean of 
mean Beeholes 
jSample Tree. 
Girth-Class. 
per Girth-Class. 
10—12 | 
f 
18 
16 
11*0 
12-5 
0 
1 
j 11-7 
0 5 
13—15 j 
[ 
19 
17 
13*75 
14-25 
3 
1 
j 14-1 
20 
r 
2 
16*5 
8 
] 
16—18J 
i 
15 
17-0 
6 
> 17-3 
7-2 
L 
12 
18-5 
7 
/ 
10 
190 
3 
19—21 - 
8 
9 
19- 5 
20- 0 
13 
17 
[ 19-7 
14-7 
13 
20-5 
26 
) 
I 
r 
11 
22-0 
30 
1 
22—24-4 
I 
6 
24-0 
12 
V 23-6 
16-3 
1 
L 
3 
24-75 
7 
f 
1 
> 
4 
25-0 
20 
i 
"Y 
t- 
<N 
1 
<M 
7 
25-0 
7 
y 25-i 
14-0 
5 
25-25 
15 
j 
28—30 
1 
28-0 
12 
28-0 
12-0 
31—33 
14 
32-0 
34 
32-0 
34-0 
The arithmetic mean girth of the sample trees is 21* 4 inches and the 
arithmetic mean number of beeholes is 11*0. The girth of the mean 
normal tree 22 years old is 29" 0 inches and the graph value in beeholes 
for this girth is 21*5. To counterbalance the effect of the abnormally 
slow-grown sample trees, the average between the arithmetic mean girth 
of the sample trees and the girth of Leete’s normal tree is taken for the 
index of attack in the plantation, viz., ~— 2 -=25*2 inches. The 
graph value for this girth is 16’25 beeholes, which is also the arithmetic 
mean of the two figures obtained above, viz., ^ 21 ? + U —16*25 bee¬ 
holes. This figure indicates a fairly high degree of attack. 
Effect of undergrowth. 
The sample trees were chosen in small groups with different types of 
undergrowth to see if there is any appreciable connection between the 
density of the underwood and the degree of attack. The girth-beehole 
[ 295 ] g2 
