348 INSECTS AFFECTING VEGETATION 



earth itself, though galleries may be run through it and under 

 stones. 



Remedial measures are few. There is no way of reaching them 

 by stomach poisons and contact insecticides must be entirely relied 

 upon even hydrocyanic acid gas fumigation is ineffective. Where 

 the insects infest fence-posts or rails, make an opening into it and 

 drench with gasoline. This will penetrate into the burrows in 

 every direction and will kill everything with which it comes into 

 contact. Bisulphide of carbon is even better, as its vapor will 

 penetrate into the ground itself and will follow the galleries, where 

 liquids would be lost long before they got far enough to do much 

 good. This application may be followed by one of creosote or other 

 similar preparation, which acts as a preservative and at the same 

 time is repellant to the insects. 



Where interior woodwork is infested the problem is less simple, 

 and the effort must be to discover the location of the colony whence 

 the insects come, the search being guided by what has been said as 

 to their general habits. Hot water, gasoline and bisulphide of carbon 

 should be freely used and in extreme cases it may be necessary to 

 tear out part of the infested woodwork and replace it by sound, dry 

 material, and preferably some that has been soaked in some creo- 

 sote preservative. If possible the ends should be isolated from 

 direct connection with infested wood or with posts that go into the 

 ground, and this may be done with tin, iron or other metal, or even 

 tar paper. Corner posts or other timbers extending into the soil 

 should be imbedded in cement or should have a thick cement wash, 

 the ends being especially well protected. This is one of those species 

 where almost each case of infestation requires special treatment, 

 based on individual conditions, and where only general principles 

 can be indicated. 



Powder-Post Beetles.* Occasionally the householder is startled 

 to find in a piece of furniture, a mantel, a picture frame or a wains- 

 coting, a number of little round holes, from some of which fine saw- 

 dust may come, to indicate that, whatever the cause of the trouble, 

 it is not at an end, and that the extent of the injury beneath the 

 outer shell or surface is a mere matter of conjecture. 



The insects in fault here are small, slender, cylindrical brown 

 beetles, known as powder-post beetles, from their habit of reducing 

 to powder the inside of the wooden parts attacked. All the hard 

 woods are liable to be infested, but usually only in the sapwood. 

 Only seasoned lumber is attacked, and if infested material is worked 

 up into furniture or fittings, the insects will continue their work 

 below the outer surface and will emerge in due time, through even 

 a coating of paint, oil or varish. 



Heavy coatings of benzine, turpentine or gasoline, as may be 

 indicated, are the only things that can be used in suitable cases. 

 These materials penetrate through the small exit holes, soak into the 

 galleries and kill everything with which they come into contact. 

 Where there is no finish of paint or varnish, a coat of creosote is 

 sometimes useful and tends to prevent further attack. Ordinarily, 



*See illustration on page CC3. 



