Part III.] 
Beeson : Beehole Borer of Teak. 
65 
index of attack for the 23-26 year old trees. Sample Trees Nos. 28, 26, 
20, 29 and 37 have a mean girth of 30-2 inches, and a mean age of 47, 
and a mean number of beeholes of 26-6. The beehole-girth curve gives 
a graphical value of 22-0 beeholes for a 30-2 inch tree. This value is 
taken as the index of attack for trees forming the older part of the stand. 
Making allowance for the difference in age it would appear that the 
natural forest trees are quite as badly attacked as the plantation trees. 
With regard to the annual distribution of the borer attack in this 
area three graphs have been prepared, one for the plantation trees 21 
years old, the second for natural forest trees approximately 25 years old 
and the third for natural forest trees with a mean age of 47 [see Annual 
Incidence Graphs]. The constant parallelism in the behaviour of the 
three curves is striking and indicates that the dating of the beeholes 
is free from serious errors. 
Table 12. —Annual Incidence in Natural Forest , Mohnyin Reserve , 
Katha, 1919. 
Total Attacks 
5 
12 
3 
15 
33 
68 
9-6 
6 
24 
34 
24 
45 
133 
22-0; 
1918 
1 
1 
0 
1 
3 
6 
0-8 
0 
2 
1 
1 
3 
7 
1-2 
1917 
0 
1 
0 
0 
1 
2 
0-3 
0 
0 
0 
0 
2 
Q 
0-3 
1916 
1 
3 
0 
1 
0 
5 
0-7 
0 
0 
3 
0 
2 
5 
0-8 
1915 
0 
3 
0 
1 
2 
6 
0-8 
0 
1 
1 
1 
1 
4 
0-7 
1914 
0 
0 
0 
0 
4 
4 
0-6 
0 
1 
3 
1 
3 
8 
1-3 
1913 
0 
0 
0 
3 
1 
4 
0-6 
0 
0 
0 
0 
1 
1 
0-2 
1912 
3 
0 
0 
2 
3 
8 
1-2 
0 
0 
4 
0 
2 
6 
10 
1911 
2 
0 
2 
3 
7 
1-0 
1 
5 
0 
2 
5 
13 
21 
1910 
0 
0 
1 
8 
9 
1-2 
0 
4 
3 
4 
11 
1-8 
1909 
0 
0 
1 
3 
4 
0.6 
0 
0 
3 
0 
1 
4 
0-7 
1908 
0 
0 
0 
1 
1 
0-1 
0 
0 
1 
1 
1 
3 
0*5 
1907 
1 
0 
0 
0 
1 
0-1 
0 
0 
0 
1 
1 
2 
0-3 
1906 
1 
0 
0 
0 
1 
01 
0 
3 
3 
0 
0 
6 
1*0 
1905 
0 
1 
0 
1 
2 
0-3 
0 
0 
1 
0 
0 
1 
0-2 
1904 
0 
0 
0 
0 
0 
0-1 
0 
0 
4 
0 
3 
8 
1-3 
1903 M 
0 
0 
0 
1 
1 
0-1 
1 
0 
0 
0 
1 
1 
0-2 
1902 « 
1 
0 
1 
0 
1 
0-3 
0 
1 
1 
0 
0 
2 
0-3 
1901 | 
0 
0 
1 
2 
0-3 
0 
1 
0 
0 
0 
3 
0-5 
1900 
2 
0 
0 
2 
0-1 
1 
0 
1 
4 
3 
8 
1-3 
1899 
0 
1 
1 
0-0 
0 
1 
1 
1 
1 
5 
0-8 
1898 Z 
0 
0 
0-3 
1 
5 
3 
2 
3 
13 
2-0 
1897 g 
2 
2 
0 
4 
1 
1 
6 
1-6 
1896 
0 
2 
4 
6 
1-0 
1895 
0 
0 
0 
2 
0-3 
1894 
2 
0 
0 
0 
0-0 
1893 
0 
0 
0 
00 
1892 
0 
0 
0 
0-0 
1891 
0 
0 
0 
0-0 
1890 
0 
0 
0 
0-0 
1889 
0 
0 
0 
0-0 
1888 
1 
2 
3 
0-5. 
1887 
1 
0 
1 
0-2 
1886 
0 
0 
0 
00 
1885 
1 
0 
1 
0-2 
1881-1884 
0 
0 
0-0 
1880 
# 
1 
1 
0-2 
1861-1879 
Age in Years 
. 
24 
25 
23 
24 
1 26 
CO 
1 44 
1 42 
37 
IjW 
58 
CO 
w a 
Girth in Inches 
. 
. 
|_17_ 
19 
| 20 
22 
I 30 
H 
§s 
Q < 
23 
; 27 
30 
|_33_ 
37 
o C 
Serial No. of Sample Tree 
I 38 
34 
35 
33 
1 27 
H 
H > 
jir 
26 
20 
29 
73 
o 
H 
H > 
[ 293 ] 
