Wood wasps or horntail wasps can be particularly unwanted due to their destructive habits. They are not necessarily overly aggressive insects, but they eat wood and burrow their larvae deep within spruce, pine and fir. Besides trees, they can cause damage to your house. There are steps you can take to destroy their hidden nests to avoid further damage and prevent future nesting.
Locate the nest. You'll notice female wasps burrowing in the wood as they are building the nests. Look for wood with lots of small holes in it.
Use a borate-based wood treatment on the area and surroundings. This will penetrate the wood with a poison that is toxic to the wood wasps.
Use Drione Insecticide Dust on the area, getting it into the existing holes caused by the wood wasps. This dusting dries out the wasps and kills them.
Apply wood putty to the nesting area roughly a week after the dusting. The wasps will die or leave the area as the insecticide settles in. Applying the wood putty to the holes prevents the wasps from returning to the nesting area.
Use Raid Wasp and Hornet Killer for any remaining wood wasps that linger in the area. This insecticide should kill the wasps on contact.
When initially applying the treatments, be sure to wear protective clothing to prevent any angered wasps from taking it out on you.
If allergic to bees, allow someone else to apply the killing methods to prevent an unwanted trip the emergency room.