. Defects in timber caused by insects. Wood; Forest insects. DEFECTS IX TIMBER CAUSED BY IXSECTS 35 The burrows are tightly packed with pellets of excrement, and shingle stock is full of holes. (Fig. 27.) The injury occurs in living, dying, or dead trees, and consists of a flattened, oval, gradually enlarging, more or less tortuously winding mine or wormhole, which, when completed, widens out into an elongate-oval pupal cell. This cell connects with the outer surface by a short, oval exit hole. The mine has its surface marked by fine transverse, crescentic lines, and is usually tightly packed
. Defects in timber caused by insects. Wood; Forest insects. DEFECTS IX TIMBER CAUSED BY IXSECTS 35 The burrows are tightly packed with pellets of excrement, and shingle stock is full of holes. (Fig. 27.) The injury occurs in living, dying, or dead trees, and consists of a flattened, oval, gradually enlarging, more or less tortuously winding mine or wormhole, which, when completed, widens out into an elongate-oval pupal cell. This cell connects with the outer surface by a short, oval exit hole. The mine has its surface marked by fine transverse, crescentic lines, and is usually tightly packed with saw- dustlike borings and pellets of woody excrement. To prevent such injury, the forest should be kept clear of dead and dying trees and of felled trees which afford ideal breeding spots. Such trees might be used for fuel, or they could be piled with the limbs and tops and burned. If trees must be deadened in the lumbering opera- tions, the " deadening " should be done at a time of the year when the sap is not actively flowing. October, No- vember, and December would probably be the best months for this. If the timber must be felled and left in the woods for a time, the felling should be done during the same months, and the logs should be barked and left so that they will dry quickly and thus become distasteful to these borers. If the timber is found to be newly in- fested while standing, or on felling, the most practical remedy is to cut it into logs at once and place the logs in a pond or stream so that the larvae will be destroyed and further damage prevented. If the damage has been done before the lumberman has noticed the injury, which is usually the case, much loss can often be prevented by utilizing the damaged stock to the best advantage. It may be used for poles, posts, plank- ing, sills, small construction timbers, or where the wormholes are not particularly detrimental; it should not be used for cooperage, shipbuilding, shingles, doors, finishing, cab
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisherwa, booksubjectwood
