Insects in Wood Products 



435 



be more or less susceptible to termite 

 attack. In accelerated laboratory tests, 

 the research men discovered the sus- 

 ceptibility to termite attack of light 

 wall panels made of paper honeycomb, 

 impregnated with a synthetic resin and 

 covered with thin sheets of aluminum ; 

 fiberboard made from palmetto; and 

 wall panel made of pressed excelsior, 

 bonded with an inorganic cement. 

 Such materials need not be considered 

 unsuitable for construction, but they do 

 need further chemical protection or 

 should be used in buildings for which 

 termite-proof construction has been 

 provided. Some of the honeycomb pan- 

 els apparently become weakened more 

 rapidly than untreated wood. 



SOMETIMES CHEMICALS must be 

 used sprays, dips, wood preservatives, 

 soil poisons, poison dusts, or toxic 

 fumigants. Chemicals suitable for pre- 

 serving structural timbers have been 

 available for years, but only recently 

 were effective and lasting chemicals 

 discovered for use as sprays or dips to 

 protect green logs as well as green and 

 seasoning lumber from borer attack. 



DDT and benzene hexachloride in 

 oil solutions are effective in preventing 

 attack by bark beetles, sawyers, and 

 ambrosia beetles in green logs and 

 lumber. 



Benzene hexachloride is better than 

 DDT against ambrosia beetles. 



Borax and microfine sulfur in water 

 solution or suspension have been rec- 

 ommended to the Army for use as pro- 

 tective dips against Lyctus powder-post 

 beetles for unseasoned implement han- 

 dle stock. 



For seasoned tool handles, penta- 

 chlorphenol in oil solution has been 

 specified as a preventive dip. 



Solutions of DDT are effective in 

 protecting bamboo and tool handles, 

 but such preventive dips do not stop 

 rot or decay. The pentachlorphenol 

 protects against both insects and decay. 



Powder-post beetles infesting build- 

 ings or furniture can be controlled by 

 pentachlorphenol sprays. 



Tests in this country and in the 



Tropics of new chemical wood preser- 

 vatives disclosed that copper naphthe- 

 nate and pentachlorphenol protect 

 ammunition boxes, crates, pallets, and 

 the like from attack by wood-boring 

 insects. 



The arsenicals and pentachlorphenol 

 give effective protection against ter- 

 mites when used as integral treatments 

 during manufacture for fiberboards. 



Poisoning the soil about the founda- 

 tion of buildings is useful as a supple- 

 mentary treatment against termites 

 where structural insulation is not prac- 

 ticable. Suitable for such a purpose are 

 arsenicals, chlorinated phenols, chlori- 

 nated benzenes, DDT-in-oil solution, 

 and many other chemicals. Different 

 types of soil and moisture conditions, 

 types of construction, and cost deter- 

 mine which to use. Only odorless soil 

 poisons should be used in places where 

 food is near or in enclosed areas that 

 are poorly ventilated. 



Government research men and mem- 

 bers of the National Pest Control Asso- 

 ciation have written standard specifi- 

 cations for the control of termites in 

 buildings. Included were structural and 

 chemical methods of protection, some- 

 what as outlined here. 



The specifications have helped the 

 industry and the public all hands ex- 

 cept the termites. 



In southern California members of 

 the pest-control industry recently con- 

 ducted cooperative tests with the 

 Bureau of Entomology and Plant Quar- 

 antine to discover more effective liquid 

 chemical sprays or dusts for the control 

 of dry-wood or nonsubterranean ter- 

 mites. During these experiments it was 

 shown that isolated buildings tightly 

 sealed with heavy paper can be rid of 

 the dry-wood termites or powder-post 

 beetles by fumigation with heavy dos- 

 ages of hydrocyanic acid gas or methyl 

 bromide. Fairly long periods of fumi- 

 gation and forced aeration are re- 

 quired. This is dangerous work that 

 should be done only by professional 

 fumigators. Special precautions must 

 be taken to protect the building, ma- 

 terial stored therein, and human life. 



