There are two options for such a small icon. The first would be to inject it with some Baygon Aerosol through any cracks or seams in the metal cover. If you don't think this is going to reach deep enough into the wood icon, drill some port holes through the bottom and treat it from this side. You should be able to get good penetration and coverage with the aerosol alone. If you still have activity 2-3 months after treating, you'll need to get some of the Jecta Gel and inject this through access holes on the bottom that can be drilled if needed. The bottom line is you must get this wood treated through and through if you want to kill off the feeding larvae as explained in our Powderpost Beetle Control article.