The Technique of FURNITURE MAKING

Insect pests

Most important of these are the lyctus, death - watch and furniture beetles; and of secondary importance, in that they attack only unseasoned, sickly or softwood timber, the pinhole borers, longhorn beetles and giant wood-wasp. All these pests are winged and capable of flight in search of suitable breeding - places and in every case it is the larva or worm which actually attacks the wood.

Pinhole borers (ambrosia beetles)

These are confined to tropical countries and attack the sapwood and heartwood of freshly felled logs waiting for milling. Wood attacked by pinhole borers can be recognized immediately by the very small neat exit holes, usually stained with fungus, and the straight tunnels empty of dust running both with and across the grain. Structural damage is usually slight, and wood which has been attacked can safely be used in this country, although obviously there must be prejudice against it owing to the apparent similarity with the ravages of the true furniture beetle.

Lyctus (powder-post) beetle (21 :B)

Several species exist and are common to timber - yards where they attack the sapwood of hard­woods with large pores, notably oak, ash, elm and coarse-grained walnuts. Close-grained woods and softwoods are usually immune, as the large eggs are not laid in cracks or crevices but in the actual pores of the wood which must be wide enough to receive them. The attack usually dies out as the wood becomes seasoned and the available starch is exhausted, but in the meantime the entire sapwood can be reduced to a flour-like dust. The mature beetle is dun coloured, with a narrow body about 3/16 in (4.7 mm) long, slightly larger than the furniture beetle, and with a more pronounced head.