It is very important that tags go in the middle of the discal cell. Chip Taylor recently told me that if a Monarch is tagged on the hindwing that the hindwing will break and that butterfly will probably not make it to Mexico.
If you have a Facebook account you can see that this Monarch was not tagged correctly:
http://www.facebook.com/photo.php?fbid= ... =1&theater
Well, here goes the video on how to tag a Monarch.
http://s964.photobucket.com/albums/ae12 ... ure160.mp4