The treatment is also effective against infestations in furniture and other wood products.
For best results in treating any kind of material, first remove the finish. This is especially desirable when you treat a large area, such as a floor, but it may not be desirable when you treat ornamental products. Where an infestation in a floor is so small that removal of the finish is undesirable, go ahead and treat the floor, but do not walk on it until it has dried. The drying takes several hours.
The old house borer and other beetles that do not make entrance holes in the surface of the wood can also be controlled by surface applications of these chemicals. Larger quantities must be used, however, especially where thicker wood is concerned, such as floor joists, studs, and roof rafters. For such materials, at least 1.5 pints of the insecticide per cubic foot of wood is needed to reach the beetle larvae. This is equivalent to treating the exposed surfaces of 7 linear feet of a 2- by 10-inch floor joist, 12 feet of a 2- by 6-inch roof rafter, 18 feet of 2- by 4-inch studding, or 12 square feet of subflooring. Even with this thorough treatment, it may take from 3 weeks to 3 months before all the larvae are reached and killed.
The homeowner can best apply such a quantity of insecticide by using a sprayer or a pint-size plastic wash bottle of the squeeze type, equipped with a tube that will produce a pinpoint stream. This makes it possible to apply small enough quantities to cover the surface without causing the liquid to run off. Repeated applications at different times are necessary for complete absorption by the wood and effective penetration. A pest-control operator can obtain results quickly by injecting the chemical under pressure through boreholes spaced at short intervals in the infested wood.
Slow-Diffusion Method
Where pressure equipment is not available and you want to use the bore-hole or slow-diffusion method on isolated infestations in wood that is readily accessible, you can use the following procedure:
1. Bore a downslanting hole about ½ inch in diameter and 1 inch deep into the wood near the place where a larva is working.
2. Insert a tight-fitting metal or glass tube in the hole. Let about ¼ inch of the tube project.
3. Place one end of a rubber tube over the projecting portion of the metal or glass tube, and connect the other end with a funnel. The funnel should be supported so that it will stay in place until the treatment has been completed.
4. Pour insecticide into the funnel. Use any of the preparations mentioned in the discussion of spraying and brushing. Leave the equipment in place about 48 hours, or until the insecticide is taken up. The insecticide flows into the infested wood, is absorbed for a distance of several inches around the hole, and reaches and kills the larva.