Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-07-13
BUGS THAT BORE IN WOOD
The Stains Occurring in Woods Are
the Result of the WORK of These
Little Inseets.


done to timber by boring insects. This is a
cause Of a money loss that amounts to mil
lions of dollars yearly. Some of the crea-
lures responsible for the mischief are
beetles and others are moths. Certain spe-
cies attack dead wood exclusively, while
others feed only on living trees The injury
thus occasioned cuts down the market price
of the timber or Of the lumber sawn from it.
The most interesting Of these insets has
been discovered only recently. It is ac-
countable for the peculiar black stains
which occur in oak, poplar, beech and BIRCH
They are of such common occurrence in oak
that. In looking over a large lot Of that
kind Of lumber, one can scarcely find a
piece which does not show one or more OF
the discolored patches. The latter surround
peculiar black holes. from which the stain
seems to have extended. They are often
found near the heart-wood of large trees
showing that the damage was done a long
time ago.
Professor A. d. Hopkins. who discovered
the beetle that produces the holes and
stains. too, the trouble to ascertain in
number of instances, the precise dates at
which they were made. By counting the
annual rings in oak logs. he learned that
one OF the stains was made in 1853, another
In 1888, and a third in 14I9-thirteen years
before Columbus discovered America.
Dcpreciating the Value.
Out OF respect for the individual insect
which thus left behind it a record of pre-
Columbian activity. the name Columbian
timber beetle has been conferred upon the
species. 1t appears that 1t attacks only the
healthy wood of living trees The black
holes are its galleries. which have side
chambers that serve as nursery rooms
where the young remain from the time they
are Matched until they are grown up. An
egg is deposited by the parent in each of
the chambers. From the eggs come minute
grubs. which feed on the sap.
Nobody knows exactly what makes the
stains. which are apt to spread for a con-
siderable distance through the woods, some,
times two or three feet. 1t may be that an
acid is excreted by the insect and produces
the discoloration. Or perhaps 1t Is merely
that the sap, mixed with the excrement of
the developing young. escapes from the
ducts which are ruptured by the boring and
makes the stain.
The phenomenon is open to anybody's
on-hand observation. In a piece of oak fur
niture 1t Is not uncommon to find ten or
twenty such spots. They are frequently to
be noticed In wainscoting and in osk floor
ing. When they occur in a piece of lumber
or timber its value Is reduced at the rate
Of $ to SO per 1000 feet. One million feet
OF lumber having such defects may be de-
preciated by $4,000. If the split or sawed
surface exposes an entrance to a set of gal
leries In slaves or shingles the defects
somewhat resemble small Steam monitors.
the black hole forming the smokestack.
This likeness has long been noticed by lum-
bermen. who term the marks steamboats,"
The rule is that IL stare contains more
than two steamboats, 1t is no good
An Artistic Importance.
Nevertheless. oddly enough. there is be-
ginning to be demand for wood that
shows these stains. The latter often pro-
duce beautiful effects. In the course of
time the tree repairs the injury made by
the insect. closing up the hole so that only
a discoloration is left. Far from being OBJ
jectionable, these stains in articles of fur
niture and In the natural wood finish of
floors and wainscctins ought to serve as
pleasing objects to draw attention to ma
lures handiwork.
This remark does not apply to holes made
In timber by certain other kinds of in
sects. What are termed pin holes are
commonly net with in oak and chestnut.
OFTEN there Is a great number of them
within small space. They are made by
small. long. round-bodied worms. which
are the young of winged beetles. The lat
ter deposit their eggs in the crevices, and
the minute worms newly Matched. bore d.
rectly into the wood forming at first holes
so small as to be scarcely visible to the
naked eye. They extend their burrows to
the heart of the trees. and remain in them
until they are matured beetles. The holes,
which frequently extend several feet, are
called pin holes" from the fact that they
are often plugged by stave makers and
coopers with small wooden pins.
This timber worm will not infest a living
tree unless some wound in the bark or
wood occurs in which the parent beetle
can deposit her eggs. A wound produced
by a small bullet in a young and thrifty
tree has been known to start a colony. In
anothec- Instance a wound made by load
of shot in the bark of young tree six
inches in diameter was the means Of start
ing SO many of the worms to work in the
wood at that point that the tree died.
Another Of the many timber-eating in
sects Is large grub, the young of a moth.
1t is called the carpenter worm" 1t is
reckoned that manufactured timber pro-
ducts are deprecated by boring insects to
the extent of from to so per cent, depend
ing on the kind of wood and the locality.