Hylotrupes . The insect is rather large in both the larval and adult stages 

 and mates channels and holes in the vrood up to l/U inch in diameter. It 

 attacks all soft woods and is found Drincipally in large timbers such as 

 joists and beams. Due perhaps to the increased use of sapv/ood, pointed 

 out earlier, it appears that this insect is becoming increasingly common 

 in the United Stat s. This very point is brought out in a recent report 

 from Sweden which presents the findings of a survey of wood-destroying 

 insects and also states that the cost of repairing existing damage caused 

 by this borer in Svreden irould amount to over 2;?jO0O,0OO. Reports from 

 other parts of Europe, North and South Africa indicate a siinilar situation 

 in these areas. 



The borer has not been so intensively studied in this country, Hov;ever, 

 it has been found in outdoor structures, such as in bridge timbers, poles, 

 and piers, as v^ell as in all parts of dwellings, warehouses, and like 

 structures. The size of the insect added to its life cycle of from 3 to 7 

 years, means the rapid destruction of wood. High temperatures and humidity 

 favor its optimum development. 



There are several other species of powder-post beetles ivhich because of 

 small size and inconspicuous activity attract little attention. Neverthe- 

 less, as a Yfhole, they likewise cause severe damage. It is unusual to 

 find foundation timbers, particularlj'' in basementless structures, free 

 from attack by one or more of these species. Unfortunately, presence of the 

 insect is not detected until failure of tinber is noted and, as frequently 

 happens, the causal apent is ignored, the timber is replaced, and the general 

 infestation continues. 



One insect, knovm as the inrharf" borer, stands apart from the powder-post 

 beetle in its relationship and habits. It is usually associated with decay 

 fungi in very moist wood and under such conditions has been observed hasten- 

 ing the destruction of piling, decks under wharves, boardwalks, telephone 

 poles, fences, piers, and even buildings. It has been reported from 

 numerous points in the United States, particularly along the coast, and 

 from other parts of the vrorld, and, although it has not received a great 

 deal of study it is known to be capable of doing considerable damage. 



Very little is knonvn regarding the biology and control of this insect. 

 Treatment of wood with preservative deters its activity for a period of 

 time, but it will attack i.'hereo-er impregnations are poor or leaching of 

 chemicals has begun. 



There is much yet to be learned of the biology and practical prevention and 

 control of v/ood-borin^f beetles. It is believed that the residual action 

 of new synthetic insecticides offers considerable promise in this regard. 

 However, the method of introducing these chemicals into nrood to reach deep 

 infestations remains a problem. F-amigation of small buildings, furniture, 

 or tool stock v.'ith methyl bromide is very effective but is limited because 

 no protection from future attack is offered and this method cannot be used 

 for large buildings or their contents. In some cases the impregnation of 

 wood with a preservative by soaking or pressure treatment offers a worth- 



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