Show FLAT HEADED BORERS Flat headed borers are among the most important of the borers infesting forest trees in the united states some mine mi nethe the leaves eaves one burrows into the cones a number bore into the inner bark and outer wood of the trunk branches and roots while the majority excavate oval winding wormholes worm holes throughout the sound or decaying sapwood and h ae e artwood a r tw 0 0 d the bark borers often girdle and kill hill healthy trees or those injured by fire floods droughts diseases other insects or careless lumbering and at other times limes weaken trees so that they become arcome easy victims of diseases other insects or unfavorable environment viron ment sometimes when they do not kill the tree outright their work cams causes s dead limbs or twigs or serious sarious defects checks or gum spots to form in the wood or swollen galls to form on the branches the wood borers mine the sapwood and heartwood of the trunk top and larger branches and thus destroy or seriously injure a large amount of the trees most valuable product its timber wormholes Worm holes bples will cause the finest grade clear lumber to become unfit for the higher grade uses and therefore at the hillier higher prices bu reau of entomology U S department part ment of agriculture |