I make sticky traps to catch gnats and white flies around my plants. Using yellow paper saucers and plastic lids, plus a small foam brush, I coat the saucers and lids with an auto oil additive called MOTOR HONEY. It is very inexpensive, comes in a small bottle, and can be bought wherever motor oil is sold. I hang the lids and saucers with a hook made from wire or a paper clip. I've even dabbed it on pot edges to trap pesky gnats. It works! Don't put it on too heavily or it will drip.