28 
Indian Forest Records. 
[Vol. VI 
If allowed to remain unbarked for more than one month, the sap-wood 
also should be removed, wherever insects have commenced work. 
The bark and sap-wood need not be burned, but, if possible, should 
be scattered or exposed to the sun. 
Tops and branchwood over 18 inches girth, left on the felling-areas, 
should be treated in the same way as logs, i.e ., bark and sap-wood 
removed. This material forms the chief breeding ground of the borers, 
and the object of control measures is to reduce it as far as possible for 
the time and labour expended. In any case, at least 75% of the 
unsaleable material left on felling-areas should be treated. 
2. Isolated Trees or Groups .—Recently dead, dying, or green attacked 
trees, met with in departmental operations, viz., coupe-marking, 
cleaning, creeper-cutting, dry wood marking, etc., should be disposed 
of at once. If the early stages of the attack occur, immediate felling 
and barking will be effective, but if the insects have already penetrated 
to the heart-wood, i.e., in trees dead three months and more, nothing 
practical can be done, except immediate conversion or removal of the 
logs to localities outside the forest. 
Summary. 
Diapus furtivus, Samps, is one of the shot-hole borers attacking Sal 
in the Sub-Himalayan and Central Indian Sal areas. It is able to kill 
off trees with diseased roots, but its attack is not fatal to trees weakened 
by defoliation, creepers, unsuitable local conditions, etc. It normally 
breeds in newly dead or felled trees and is particularly abundant in 
felling-areas and depots. It is active throughout the year. 
The beetles bore a system of galleries, in the sap-wood and heart- 
wood of Sal on a definite pattern, and bring up a brood of about 100 
larvae in the galleries. The food of the larvae is not wood-dust, but 
an ambrosia fungus which grows on the walls of the brood-galleries, 
supplemented by wood-sap. The length of the life-cycle may be 
10 weeks or more, but owing to the prolonged egg-laying period of the 
mother beetle, emergence of the brood is extended over a period of 5 
or 6 weeks. It is not possible to determine the minimum number of 
generations from the field-data. There are no marked swarm periods 
as all stages of the insect are met with throughout the year. 
Its chief economic importance lies in the technical damage to 
unbarked timber, which takes the form of shot-holes and lines and 
stained wood defects. It may be controlled by early barking on felling- 
areas, and the removal of newly dead trees in other parts of the forest. 
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