Assuming you transferred from a different world, you can delete from casual 8 - wait for it to fully delete (which will take around 5 days) then transfer from the new world (in your case 109) - as long as you did not transfer previously from 109. You can only transfer once from each world to a casual world.
To use an example : you could transfer from 108 to Casual 8 (if its the newest casual world), then delete from casual 8, then transfer from 109 to Casual 8 (again assuming its the newest world still) - you could not however transfer from 108 again.