A treatise on the origin, progress, prevention, and cure of dry rot in timber

by Thomas Allen Britton

4th. Wild animals eat the woodsmen.

Teak-oil, extracted from teak chips, was, in 1857, recommended by a Mr. Brown to the Government of St. Helena, through the Government of Madras. Timber coated with this oil, as reported to the Secretary to the Government of Madras by the several executive engineers of the Public Works Department, even when placed in a nest of white ants, was not touched by them. The cost of this oil, in certain experiments made by order of the Madras Government, in 1866, was reported to be 6¾ annas for 1¼ ounce, which is too expensive. In the central provinces the cost would be 1¼ anna per quart.[33]

In the East Indies there are several species of wood-cutter (Xylocopa) and carpenter bee (Xylocopa), which confine their ravages to the wood after it has been felled. The wood-cutter tunnels through the beams and posts of buildings, which they frequent in great numbers. The passages are from 12 to 15 inches long, and more than half an inch in diameter. If the insects are numerous, their ravages are dangerously destructive, and they soon render beams unsafe for supporting the roof.

The carpenter bee of Southern Africa is one of those curious insects which construct a series of cells in wood. After completing their burrow, which is open at each end, they close the bottom with a flooring of agglutinated sawdust, formed of the morsels bitten off during the operation of burrowing, lay an egg upon this floor, insert a quantity of “bee-bread,” made of the pollen of flowers and their juices, and then cover the whole with a layer of the same substance that was used for the floor. Upon this is laid another egg, another supply of bee-bread is inserted, and a fresh layer of sawdust superimposed. Each layer is therefore the floor of one cell and the ceiling of another, and the insect makes on the average about ten or twelve of these cells.

The carpenter bee destroys the woodwork of buildings in the north of Ceylon, but in the south of the island woodwork has two enemies to contend against, viz. the porcupine and a little beetle. The porcupine destroys many of the young palm-trees, and the ravages of the cocoa-nut beetle (Longicornes) are painfully familiar to the cocoa-nut planters. The species of beetle, called by the Singalese “cooroominya,” is very destructive to timbers. It also makes its way into the stems of the younger trees, and after perforating them in all directions, it forms a cocoon of the gnawed wood and sawdust, in which it reposes during its sleep as a pupa, till the arrival of the period when it emerges as a perfect beetle. Mr. Capper relates that in passing through several cocoa-nut plantations, “varying in extent from twenty to fifty acres, and about two to three years old, and in these I did not discover a single young tree untouched by the cooroominya.”

Carpenter Bees “at work”.

Sir E. Tennant thus writes of the operations of the carpenter bee on the wooden columns of the Colonial Secretary’s official residence, at Kandy, Ceylon: “So soon as the day grew warm, these active creatures were at work perforating the wooden columns which supported the verandah. They poised themselves on their shining purple wings, as they made the first lodgment in the wood, enlivening the work with an uninterrupted hum of delight, which was audible to a considerable distance. When the excavation had proceeded so far that the insect could descend into it, the music was suspended, but renewed from time to time, as the little creature came to the orifice to throw out the chips, to rest, or to enjoy the fresh air. By degrees a mound of sawdust was formed at the base of the pillar, consisting of particles abraded by the mandibles of the bee; and these, when the hollow was completed to the depth of several inches, were partially replaced in the excavation, after being agglutinated to form partitions between the eggs, as they are deposited within.”

Fortunately in England the owner of a house has no opportunity of watching (“with an uninterrupted hum of delight, audible to a considerable distance”) the operations of the carpenter bee, on the wooden beams and posts of his building.

We must now consider the ways of the wood-beetle, which will be found described in the next chapter, and only write a few words before closing this. A modern engineer is no sluggard, of that we are certain; but if he intends erecting large buildings in any of the places abroad which we have referred to, he will find it very necessary to pay particular notice of the following words of King Solomon: