52 
Indian Forest Records. 
[VOL. VIII. 
of the beehole borer is detected. In the records of this note all larval 
galleries of over 1J inches in length have been classed as “ beeholes.” 
Early larval work of smaller dimensions and scars on the sapwood 
have not been included in the beehole incidence, although they have 
been dated and recorded as subsidiary information on the annual 
frequency of attack. Where a beehole runs from one billet to the 
next above, it is recorded in the billet in which its base occurs. 
The Dating of Beeholes. 
[Vide Plate VI.] 
As is pointed out in the section dealing with the life-history of the 
borer, it is believed that the life-cycle is normally annual. The age of a 
beehole can therefore be determined by counting the number of annual 
rings in the wood overlaying the sapwood chamber and the aperture of 
the beehole. 
The most convenient method of obtaining cross-sections for the 
examination of the annual ring is to hold the wedge containing the 
mouth of the beehole at about 45 degrees on a chopping-Wock and to 
cut vertically with a heavy curved dah. The oblique surface so obtained 
expands the annual rings, and emphasises the presence of the larger 
pores and lines marking the spring wood. From time to time it is advis¬ 
able to examine the cross-sections of the scars representing embay- 
ments and lobes of the sapwood chamber and callus in the mouth 
of the beehole, to locate the actual zone of attack. Error in dating 
frequently occurs unless several readings are taken. 
The Annual Ring .—The annual ring of teak is marked by a zone of 
large and very conspicuous vessels, that is formed when the year’s growth 
recommences. Outside this zone the vessels decrease in calibre, at 
first suddenly, and then gradually, attaining a minimum in the outer 
zone of the autumn wood. In some trees the later-formed small-pored 
wood contains sparsely scattered large vessels, but in almost all cases 
there is no difficulty in recognising a true ring. Very little informa¬ 
tion is available on the histology of the annual ring in teak, but 
for the accurate dating of beeholes it is essential to know the process of 
formation of the large pore-ring. Mr. Rodger is of opinion that the 
pore-ring in teak is formed in Burma between the beginning of 
May and the end of July or August, and that the autumn wood is 
formed between August and December. He considers that the rest 
period during which no wood is formed, lasts during January to about 
April. 
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