. An annotated list of the important North American forest insects. Forest insects. Washington, D. C. July, 1927 DEFECTS IN TIMBER CAUSED BY INSECTS By Thomas E. Snyder, Entomologist, Forest Insect Investigatians, Bureau of Entomology CONTENTS Page Introduction 1 Types of insect defects ; definitions- 4 Pinlioles 6 Grub holes G Powder post 7 Defects classed as pinholes 7 I'inhole defects formed in living trees ; a nonpreventable loss- 10 Pinholes in living trees caused by ambrosia beetles- 10 Pinholes in living trees caused by timber worms- 14 Pinhole defects formed in wood after the trees are
. An annotated list of the important North American forest insects. Forest insects. Washington, D. C. July, 1927 DEFECTS IN TIMBER CAUSED BY INSECTS By Thomas E. Snyder, Entomologist, Forest Insect Investigatians, Bureau of Entomology CONTENTS Page Introduction 1 Types of insect defects ; definitions- 4 Pinlioles 6 Grub holes G Powder post 7 Defects classed as pinholes 7 I'inhole defects formed in living trees ; a nonpreventable loss- 10 Pinholes in living trees caused by ambrosia beetles- 10 Pinholes in living trees caused by timber worms- 14 Pinhole defects formed in wood after the trees are felled; a preventable loss 15 Pinholes in felled trees caused by ambrosia beetles. 15 Pinholes in felled trees caused by timber worms- 16 Pinhole injury to imported logs- 22 Defects classed as grub holes or wormholes 23 Grub-hole injury to living trees ; a nonpreventable loss 25 Grub-hole injury to green sav/ logs and lumber; a prevent- able loss 26 Defects classed as powder post 27 I'owder post caused by Lyctus beetles 28 Page Defects classed as powder post—Con. Powder post caused by Ptinidae and Anobiidae 32 Powder post caused by Bostrich- idae 32 Powder post caused by round- headed borers (Cerambycidae)- 33 Powder post caused by flat- headed borers (Buprestidae) 34 Other types of defects 36 Defects classed as ring distor- tions 36 Ring distortions caused by defoliation by the bud worm 36 Defects classed as pitch pockets and pitchy timber 37 Defects classed as gum spots or streaks 38 Defects classed as black check- 39 Defects classed as bluing or staining 40 Defects classed as pith flecks 43 Pith-fleck injury caused by the larvae of flies 43 Pith-fleck Injury caused by the feeding of adult wee- vils 43 Summary 43 Literature cited 44 INTRODUCTION It is extremely difficult to estimate the losses due to defects in timber caused by insects. Where the grade of lumber is lowered, the loss may be ascertained by the reduction in the grade, because of the number or size of the hole
Size: 1574px × 1587px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorhopkinsadandrewdelmar, bookcentury1900, bookdecade1900
