The insects that are drilling holes in the cedar shingles of our home are smaller than the bees and look to be wasps. Their hole is smaller and often there is a vertical line of them spaced 10 inches or so apart from the next. I have also seen the wasp enter up under a shingle and not return. There is a large yellowish larvae case left on one shingle. Does this sound familiar? Should I use the same products you describe for treatment of carpenter bees? I am here for only a couple more weeks and would be most thankful for a response as soon as possible.
Sounds like HORNTAILS. In fact you are right in thinking they’re some kind of wasp. They are. And they can infest any kind of wood. Horntails are not as common as carpenter bees but they readily infest decks, house siding and soffit areas commonly found on any home.
For now I would suggest you treat the holes with the DRIONE DUST we have listed in our Horntail article. Drione is fast acting and will kill them on contact. Treat every hole you can find and in theory, you should be able to knock them all out in one full swoop. Do the treatment at night, when the wasps are most likely in their nests, and by the next morning every nest you treated with a wasp inside will now be housing a dead wasp.
Now if you only have 5-10 holes to treat, the PT-230 version of Drione should be enough to get the job done.
Lastly, if you were planning on staying in the home for any length of time, I would recommend spraying any infected wood with CYPERMETHRIN to prevent future activity. But my guess is that simply dusting the holes and killing what’s active right now will take care of the current activity and afterward you should be able to stay wasp free for at least a month.