3?ART III.] 
99 
Beeson : Beehole Borer of Tealc. 
In the 24 year-old plantation (Locality 4) the basal 6 feet likewise 
contains J- of the total number of beeholes ; thence the quantity steadily 
falls with the increase in height. 
The Pyonchaung data (Locality 5) are quite different from the rest, 
and, as they are based on 5 trees only, are not typical of local 
conditions ; the curve is not shown in Diagram 3. 
The two plots in unevenaged natural forest (Localities 6 and 7) 
give somewhat dissimilar results. The plot at Mohnyin yields a graph 
that resembles that for Quarry Siding plantation (Graph No. 3) and also 
that for the Yanaungmyin plantation (Graph No. 4). The Okkyi plot, 
on the other hand, is peculiar in its more or less even distribution for 
the 40 feet of the bole. 
The conclusions drawn from a consideration of these data are as 
follows :— 
(1) In a young plantation 10-15 years, at least half the total number 
of beeholes occurs in the basal 6 feet of the tree. 
(2) As the plantation grows older the intensity of attack on the 
upper sections of the bole relatively increases, and the 
proportion of beeholes in the basal 6 feet decreases. In 
a 25 year-old plantation only 25 per cent, of the total number 
of beeholes may occur in the lower 6 feet. 
(3) At later ages the distribution of beeholes throughout the bole 
becomes more even, with an average of 6 per cent, per 3 
foot length. 
(4) At all ages, up to 50 years, there is a marked decrease in the 
percentage, of beeholes in the upper and younger portions of 
the bole. 
What happens in trees over 50 years old is, in the absence of 
analyses, conjectural; but it is possible that after height growth has 
ceased the intensity of attack increases in the upper portions of the 
bole, and produces, by the time the tree is felled, a fairly even 
distribution of beeholes. 
As regards the effect of fires and of undergrowth on the distribution 
of beeholes, nothing can be deduced from the data in their present forme 
Beeholes in Mature Trees. 
The foregoing records are from trees mainly below the age of 50 years. 
Through the kindness of Messrs the Bombay Burma Trading Corporation 
Ltd., the writer was able to spend a day in their Rangoon Mill, in June 
1919, examining the occurrence of beeholes in mature teak logs. 
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