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used in railroad construction, such as ties and culvert, bridge, and 
trestling timbers. This insect will breed in old oak logs as long as 
there is sufficient amount of sound wood for it to work in, and under 
favorable conditions it will doubtless do the same in railroad ties and 
other similar material which comes in connection with the ground. 
The chestnut timber worm (L ymexylon sericeun) is another exceed- 
ingly destructive insect to the wood of living, dying, and dead oak 
trees, stumps, logs, and heavy construction timbers as long as the con- 
ditions are-suitable for it to do so. The destruction of the wood of 
old chestnut trees throughout the Appalachian region, so far as its 
value for construction material is concerned, is well-nigh complete. 
Otherwise this durable and valuable timber would be a good substi- 
tute for the rapidly diminishing oak, and on account of its rapid 
growth from a young sprout to a tree of commercial size would be a 
most profitable forest tree to grow for future supplies. 
The giant root borer (Prionus laticollis) is another enemy of wood 
which not only breeds in the roots and stems of living oak and other 
timber trees, but in old stumps and logs, railroad and other timbers 
which, owing to their connection with the ground, retain a sufficient 
amount of moisture. Some years ago I observed a large number of 
larve, apparently of this species, in some old oak railroad ties which 
were being removed from the roadbed in front of the Baltimore and 
Ohio station in Morgantown. It is therefore evident that this class 
of large wood borers contribute not a little to the rapid deterioration 
of oak ties and other timbers. 
There is another class of Cerambyeid, or round-headed borers, of 
the Centrodera, Leptura, and other allied genera, which breed in the 
wood of dead trees and logs, hence are capable of breeding in railroad 
ties and similar construction material. There are also many species 
in the family Buprestidz with similar habit. In the Scolytidz there 
are large numbers of species which bore in the wood of living, dying, 
and dead trees and cause serious defects. Indeed, there is a long list 
of species of Coleoptera which bore in the wood of trees and construe- 
tion timbers and contribute to rapid deterioration and decay. 
In Lepidoptera there are some very destructive enemies of the wood 
of living trees, notably the carpenter worms, which infest the oak and 
locust and bore large holes through the best part of the wood. 
In Hymenoptera there are certain wood-boring bees and ants which 
do great harm to the timber and other woodwork of buildings, bridges, 
and railroads. 
In Neuroptera the termites are among the most destructive enemies 
of wood and of wooden structures, working both in the moist and 
sound wood. Recently the writer has determined that these so-called 
white ants are very injurious to railroad ties and other railroad timbers. 
Thus a great variety of insects are to blame for defective timber. 
They attack the dead, living, and felled trees, the rough manufac- 
tured product in the mill yards before it is used, after it is used in the 
