A bit of a tangent, one thing I observed is that petunias are fairly sticky to the touch, even if it's not really visible. While larger insect like loopers and

A bit of a tangent, one thing I observed is that petunias are fairly sticky to the touch, even if it's not really visible. While larger insect like loopers and cutworms are fine, small weak flying insects can get caught. Both harmful fungus gnats and helpful parasitic wasps (which would normally attack worm larvae) can get caught on the leaves.