104 
Indian Forest Records. 
[Vol. VII[. 
undergrowth; in Petsut the ghth factor dominates the undergrowth 
factor (vide p. 70). The conclusions arrived at m 1918 as to the effect 
of undergrowth (Forest Zoologist’s Report, 1918, p. 3, para 4) are not of 
general application. 
Control Measures. 
Although the investigation in its present state can by no means be 
considered to supply results of immediate practical value, the publica¬ 
tion of the available information provides concrete ideas on the extent 
of the damage due to this pest, and indicates the direction in which 
research is required for the enucleation of control measures. 
As far as natural forest is concerned nothing can be done to reduce 
the damage in girdlings of the next 10 or 20 years. The beeholes are 
already in the tree, and the additional attacks received during that 
period will affect the sale price in only a very small proportion of 
the logs. 
In plantations and regeneration areas of pure and more or less even- 
aged teak the following measures are suggested :— 
1. Thinnings should commence early and recur at short intervals 
and should be carried out so as to produce a high girth-increment in 
individual trees, as there are indications that the girth-increment can 
be made to outstrip the borer—increment. The statistical data will 
afford a means of adjusting the two factors to the development of the 
maximum yield of sound timber in the final crop. 
2. In early thinnings or cleanings, trees showing beeholes should 
be cut out unless their retention is sylviculturally essential, but in the 
middle period of the rotation the presence of visible beeholes should 
not influence the selection or rejection of trees. 
3. In thinnings the suppressed and dominated trees should be cut 
out and not left standing, as it is evident they do not act as trap-trees, 
but on the contrary are sources of infection to the more vigorous trees. 
4. The most favourable time to fell is between August and December. 
If trees are felled early in the year the borers in the mature larval and 
pupal stages will complete their development successfully. 
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