. Seasoning of wood; a treatise on the natural and artificial processes employed in the preparation of lumber for manufacture . or quite full grown. They then enter the woodand continue their excavations deep into the sapwood orheartwood until they attain their normal size. Theythen excavate pupa cells in which to transform into adults, ENEMIES OF WOOD 103 which emerge from the wood through exit holes in thesurface. This class of borers is represented by a largenumber of species. The adults, however, are seldom seenby the general observer unless cut out of the wood beforethey have energed. Fla
. Seasoning of wood; a treatise on the natural and artificial processes employed in the preparation of lumber for manufacture . or quite full grown. They then enter the woodand continue their excavations deep into the sapwood orheartwood until they attain their normal size. Theythen excavate pupa cells in which to transform into adults, ENEMIES OF WOOD 103 which emerge from the wood through exit holes in thesurface. This class of borers is represented by a largenumber of species. The adults, however, are seldom seenby the general observer unless cut out of the wood beforethey have energed. Flat-headed Borers The work of the flat-headed borers (Fig. 24) is onlydistinguished from that of the preceding by the broad,shallow burrows, and the much more oblong form of theexit holes. In general, the injuries are similiar, and effectthe same class of products, but they are of much less im-portance. The adult forms are flattened, metaUic-coloredbeetles, and represent many species, of various sizes. Timber Worms The character of the work done by this class is shownin Fig. 25. The injury consists of pinhole defects in the. Fig. 25. Work of Timber Worms in Oak. a, work of oak timber worm,Eupsalis minuta; b, barked surface; c, bark; d, sapwood timber worm,Hylocoetus lugubris, and work; e, sapwood. sapwood and heartwood of felled trees, sawlogs and hkematerial which have been left in the woods or in piles in theopen for several months during the warmer seasons. Stave 104 SEASONING OF WOOD and shingle bolts and closely piled oak lumber and squaretimbers also suffer from injury of this kind. These in-juries are made by elongate, slender worms or larvae,which hatch from eggs deposited by the adult beetles in the
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