IHP f2w
The basic requirements for the existence of fungi are moisture, suitable temperature and
food supplies. The wood itself forms the food supply and optimum temperature conditions are
in the range of 18°C to 30°C. Some fungi like Merulius lacrymans and Poria incrassata provide
moisture by themselves and seem to thrive even in fairly dry wood leading to what is technically
known as dry rot. The various symptoms of incipient decay are discolouration, abnormal
mottled appearance, roughness of surface and presence of soft spots of intense discolouration.
g p f e X One of the prime requirements in the control of fungal
attack is the dryness of timber. The timber should not be subjected to alternate wet and dry
conditions. When this is unavoidable, a proper preservative treatment should be made. Felled
trees should be air-dried as rapidly as possible and sawn timber should be kiln-seasoned
properly in accordance with good air-seasoning practice. Thereafter, they should be protected
from rain and other sources of moisture. It should be ensured that adequate ventilation is there
around the timber to prevent fungal attack. Also, no timber used in a structure should contain
sapwood which is more susceptible to fungal attack because of the food supplies stored in its
parenchyma.
h,222s
X Termites, or white ants as they are inappropriately called, are the most destructive of
all insect agencies. They are small, social insects which form vast colonies and possess
differentiated casts to carry on specialized functions in the social structure. They completely
excavate the wood at the centre leaving the outer shell intact. They also attack furniture and
wood work in houses and railway sleepers, etc.
f are small insects and they cause rapid decay of timber by converting them into fine
powder. Usually, the outer shell of timber remains intact and hence the timber looks sound
from outside until it fails completely.
( f @p v A attack sapwood of hardwoods with large pores. The
eggs are laid in the pores and the larva that comes out eats through the wood, leaving a very
fine powder. Even seasoned timber containing sapwood is not immune to attack of these small
beetles.
vE f @g A are 6 mm to 20 mm in size. They derive their name from
long curved antennae. They normally do not attack seasoned wood and mainly thrive on
timber in the forest yard. They can attack any type of wood, though they prefer sapwood. Their
bore holes are elliptical in cross-section.
e f f are very common and attack structural timber, furniture
and other wood work in house. They are less than 6 mm in size and attack both sapwood and
heartwood. The larva bores tunnels through the wood which are filled with the characteristic
oval-shape pellets.
p f @e A are very common and attack structural timber, furniture and
other wood works in houses. They are smaller than 6 mm in size and attack both sapwood and
heartwood. The larva bores tunnels through the wood which are filled with the characteristic
oval-shaped pellets.
h f @ A are somewhat larger than the previous one and the tunnels
made by these are also bigger and filled with bun-shaped pellets. They normally attack timber
infested with fungi or otherwise decayed.