Baiting dillers is a tuff job. They eat worms and grubs mostly. The dillar eradicating I did was done in the late afternoon with .22 and pellet gun. I was after large populations that had colonies leaving ankle breaking holes all over where I was running hog dogs in the dark. For such a limited problem you may have to track his schedule by putting some leaves at his entrance or fluffing the soil to get an idea if he hunting by day or night. Set up a comfy yard chair and pick him off that way.
Brent