Hello Jim, happy to help.

Here is a link to Bugfinders where you can search on and check out sap beetles.

I'm puzzled as to why you want to see if the beetles are around. From the research the U of MN Extension has done regarding oak wilt, when an oak is damaged like a branch is cut off or a weed wacker damages the bark deep enough, the beetles that carry the disease are attracted to the damage within fifteen minutes. Almost too quick for you to get near the wound and watch for them. The best approach is to check this link to Oak Wilt where the U of MN Extension maintains a warning section on the page indicating whether it's a high or low risk time to prune oaks or move oak wood. Right now it's high risk season.

Good-luck!