Freezer paper
Get a roll of freezer paper at the store. You can make any length tube you want. Just roll it two or three layers around something smaller than the holes you have in the wing ribs. Put it through the wing and then let the tube go. It will expand to the size of the holes in the ribs. You don't have to fool with gluing or taping it, it will stay where it belongs. I've done this for years--always works.