Insects in Wood Products 



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life, but do not develop different forms 

 or castes as do the true social insects, 

 the termites, ants, and bees. The holes, 

 not more than one-sixteenth of an inch 

 in diameter, are made by the adult 

 beetles. They riddle the wood, and near 

 them the wood is stained black. Seri- 

 ous losses to tight cooperage or barrel 

 stock and balsa wood for marine life 

 rafts and a lowering in grade of valu- 

 able lumber for veneer to be used in 

 houses, boats, or airplanes result from 

 their boring and staining. 



Larger holes more than one-fourth 

 of an inch in diameter are caused by 

 the young of large beetles. These young 

 are called sawyers because their borings 

 in green logs result in piles of sawdust, 

 as if the wood had been sawed by man. 

 Their gnawing can be heard, and their 

 activity is so conspicuous that it is hard 

 to convince a tree owner that it was 

 not this insect that killed his pines. 

 Actually, it was the small, grain-sized 

 bark beetles, often associated with a 

 stain fungus, that girdled the inner 

 bark and shut off the food and mois- 

 ture supply of the tree and caused its 

 death, thus preparing it for the larger 

 borers. 



Some types of insects need dry wood 

 for their food. Among them are many 

 kinds, sizes, and shapes of powder-post 

 beetles, which pulverize wood and have 

 other odd habits. One kind specializes 

 in boring into wine and whiskey bar- 

 rels. Another drills into and around 

 lead-sheathed cables, unmindful of the 

 short circuits that result when moisture 

 penetrates the insulation. Some years 

 ago one kind, like a weevil, damaged 

 the trusses in the roof of the White 

 House. An odd lot, indeed. 



An extremely destructive kind is the 

 Lyctus powder-post beetles, small, 

 winged beetles that lay their elongate 

 eggs in the pores of the sap wood of 

 certain large-pored hardwoods but do 

 not attack the heartwood. They go 

 after dry or seasoned sapwood of such 

 hardwoods as hickory, ash, oak, and 

 walnut lumber; manufactured prod- 

 ucts like tool handles, gun stocks, tent 

 stakes, wooden artillery wheels, wagon 



spokes, oars, and other products stored 

 for long periods; and, sometimes, fur- 

 niture, woodwork, flooring, and timber 

 in homes. The young reduce the wood 

 fibers to a powder from which all 

 strength is gone. The presence of these 

 insects is usually betrayed by small piles 

 of fine powder expelled from the bur- 

 rows by the young. These beetles relish 

 items like dry ax handles because they 

 find the wood rich in starch and quite 

 suitable for raising their families. 



But the ones that give householders 

 the most gray hairs and sleepless nights 

 are termites, the most destructive of 

 all. In the United States they are of 

 two main types. The subterranean 

 kind, which is the worse, requires much 

 moisture and attacks wood indirectly 

 from the moist soil. The dry- wood 

 termites directly attack dry wood. They 

 are injurious only in southern Califor- 

 nia and Florida and normally do not 

 occur in the Northern States. Termites 

 damage buildings of all types, various 

 kinds of stored materials, poles, posts, 

 derricks, mine props, and many 

 another. By their boring, also, they 

 riddle or corrode with their moist 

 excrement many materials that they 

 cannot eat. Often, however, termites 

 can be easily and cheaply controlled. 



PRECAUTIONARY MEASURES in han- 

 dling the green wood and lumber can 

 eliminate much of the damage by the 

 insects that prefer them. The meas- 

 ures are rapid moving, seasoning, sort- 

 ing, and periodic inspection. 



The logs should be handled quickly, 

 with a minimum of delay between fell- 

 ing the log and stacking the lumber for 

 drying. Drying the lumber, in the air 

 or in a kiln, will stop the insects from 

 boring. Any damage that has been 

 done to the wood usually will not af- 

 fect its strength. It is termed "sound 

 wormy grade." 



As for the beetles that prefer sea- 

 soned wood: Because only the sap- 

 wood is susceptible to them, sapwood 

 and part sapwood should be sorted and 

 piled separately from the heartwood. 

 The stacks of sapwood then should be 



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