59 
Part III.1 Beeson : Beehole Borer of Teak. 
Mr. C. G. E. Dawkins, d. f.o., who thinned this plantation in March, 
1919, was of opinion that the part of the area in which kaing grass was 
abundant and which fronted on a regeneration clearing, was the more 
severely attacked, and that more frequent signs of the borer occurred 
in scattered saplings in the grassy natural regeneration area than in the 
plantation. A special plot of 72 trees in the grassy area was examined 
in May, 1919, by the writer, and a 1918 attack of 8*3 per cent was deter¬ 
mined. In the trees felled in the interior, with undergrowth less abun¬ 
dant, the percentage of 1918 attack was 12*5. Mr. Dawkins, however, 
notes that his impression was influenced by the large proportions of 
woodpecker holes also observed. 
In other parts of the Regeneration Block examined the borer is 
everywhere conspicuous and is abundant even in two-year old stands ; 
no time was available for surveys. 
The annual incidence in the sample plot is given in the following 
table. 
Table 6. —Annual Incidence in an 8-year-old Plantation , Bilumyo, 
Katha, 1919. 
1911. 
1912. 
1913. 
1914. 
1915. 
1916. 
1917. 
1918. 
Total. 
Combined Attack, 
2 
4 
4 
1 
12 
23 
13 Trees. 
Reduced Values . 
•• 
0-04 
0-09 
0-09 
0-02 
0-26 
0-5 
In the Annual Incidence Graph the values for this sample area are 
plotted (solid red line) as for a mean tree of 15 0 inches with O'5 heeholes. 
The vertical distribution of the beeholes in this sample plot is 
given on p. 98 and in Diagram 3. 
3. Incidence in Natural Forest. 
Mr. Dawkins kindly furnished the following information on the 
occurrence of beeholes in teak logs extracted from adjoining natural 
forest [Compartment 2, Coupe A, Billumyo Reserve] in November, 
1918 to January, 1919, from girdlings of December, 1915. The beeholes 
were counted on the sawn ends only, as the logs could not be rolled or 
barked. 
Number of logs examined — 356. Number of logs with beeholes =115 
or 32-3 per cent. Total number of beeholes found = 172. 
Mean number of beeholes per log = 1’5. Maximum number 
of beeholes per log = 5. 
[ 287 ] 
