DURABILITY. S7 



the forest with the wood into the timber-yard, and sapwood 

 beetles, it is chiefly the death-watch beetle {Anohiiini* striatuin, 

 A.), and A. pertinax, L., which are most destructive to old dry 

 wood, and reduce furniture and other wooden articles to powder. 

 Several species of Ptiliniis in broad-leaved wood, and Anohiiim 

 molle in coniferous sapwood, are also commonly found in dry 

 wood under cover. 



Broad-leaved trees, especially when felled in summer, are 

 more susceptible to attacks of insects than conifers, and the 

 woods of beech, alder and lime suffer most from insects. 



In large timber-yards oakwood is chiefly exposed to destruc- 

 tion by Lymexyhm navale. t 



Among conifers those richest in resin, and then juniper and 

 the Cembran pine, are least exposed to be worm-eaten. 



[Bamboos are extremely subject to be worm-eaten, especially the 

 yearling culms, which are very soft and sappy. Only 3 to 5-year-old 

 calms which are thoroughly liguified should be used as rafters, and 

 these only after several mouths' soaking in a tank, or after being 

 floated long distances in rafts on a river. The natives of India 

 believe that bamboos felled during bright moonlight nights become 

 worm-eaten much more readily than those felled during the dark 

 half of the month when the moon does not shine at night. An 

 experiment was made by the translator at Dehra Dun to determine 

 this, and 100 bamboos were cut during the bright moonlight and 100 

 cut during the dark part of the month, and the former were much 

 more worm-eaten than the latter. It is probable that certain 

 insects, the larvae of which attack bamboos, fly only during the 

 bright moonlight nights, when they lay eggs in the bamboos. 



Whenever poles containing only sapwood, or bamboos, are used 

 for rafters, they should evidently be thoroughly dried ; when exposed 

 to smoke, as they are in the roofs of native huts, the smoke prevents 

 further danger from insects. 



The wholesale destruction of most woods in hot countries by 

 termites, or white ants, is well known, and the number of woody species 

 in India which resist their attacks is very limited. Even deodar 

 wood, in spite of the oil with which it is saturated, is sometimes 

 attacked by them, and the sapwood of every wood is eaten away 



* Manual of Foiestrv, vol. iv. p. 191. 

 + Id., p. 190. 



