Since you have cold weather outside, I'd bag the item and spray the inside of the bag with something like Ortho Home Defense. According to the labeling, it dries to a film with no adverse effects on humans and animals. Any insect that touches the film will die in short order. It may take awhile to rid the piece of all of them as you will likely have to wait until the eggs and larva in the nest(s) mature and venture out. I've use this product on exterior wood and been able to paint over it with no adhesion issues.
I've gone out to find myself. If I return before I get back, have me wait for me.
"Sawdust is Man Glitter"