. Defects in timber caused by insects. Wood; Forest insects. DEFECTS IX TIMBER CAUSED BY INSECTS 31 â â B ;. â¢.;â â Fig. 33.âHoles made by the banded ash borer (Xeoclytus capraea), one of the powder-post beetles effective preventives, but they stain the wood; hence, where they can not be used, in the light of the discovery of the place and manner of the laying of the eggs in the pores of the wood, any substances that will close the pores will prevent oviposi- tion in wood not pre- viously infested. In wood from which bee- tles have emerged, however, eggs might be laid within the exit holes. P
. Defects in timber caused by insects. Wood; Forest insects. DEFECTS IX TIMBER CAUSED BY INSECTS 31 â â B ;. â¢.;â â Fig. 33.âHoles made by the banded ash borer (Xeoclytus capraea), one of the powder-post beetles effective preventives, but they stain the wood; hence, where they can not be used, in the light of the discovery of the place and manner of the laying of the eggs in the pores of the wood, any substances that will close the pores will prevent oviposi- tion in wood not pre- viously infested. In wood from which bee- tles have emerged, however, eggs might be laid within the exit holes. Paraffin wax. varnish, linseed oil, or other fillers effectively close the pores of wood. A certain var- nish known as hard- ened gloss oil is com- monly used. Wood that has been sea- soned less than 8 to 10 months will not be attacked by Lyctus beetles; therefore, in applying chemical preventives, only sap- wood that has been seasoned for 8 to 10 months and longer need be treated. The seasonal history of these beetles indicates that preventives should be applied be- fore March 1. The great and re- curring expense of treating infested wood can be avoided by prevention of attack by proper methods of management. Since only the sapwood or whitewood is attacked by Lyctus powder-post beetles, it is recom- mended that more heartwood be used to replace sapwood. Although the demand of the trade is for white- wood handles, etc., the prejudice against heartwood is not warranted. Fig. 34.âPowder-posted ash shipbuilding lumber, show- ing coarse powdery frass in the burrows made by Xeoclytus capraea. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Snyder, Thomas Elliott, b. 1885. Washington, D. C. : U. S. Dept. of Agriculture
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisherwa, booksubjectwood
