We have a confirmed diagnosis of Powder Post Beetle. There is evidence of active infestation in 1 floor board in the master bedroom on the 2nd floor. The board involved is 1 1/2" wide x 24" long and is close to the center of the room.

I'm asking for advice on how to best address this issue. So far the options have been:
1) Remove the one board and replace it.
2) Sand the board down, have the pest control service apply a chemical to kill the beetles/larva, then stain and polyurethane.
3) Sand the entire floor, possibly have chemical applied, polyurethane with an oil base product.

We are in Missouri and don't know how this infestation occured. We currently do not see any other active powder post beetle areas in the house.

Any advice on how to address this issue is appreciated.