Grow your own decoy (#1)
Try allowing a single weed to grow as a decoy among your cultivated crops. Decoy crops may attract pests and help to keep the bad guys away from your other crops. Striped blister beetles, for instance, seem to prefer redroot pigweed to tomato plants growing nearby. To keep the insects from moving to your tomatoes, check the pigweed each morning and shake off any beetles into a bucket of soapy water.
Photo: (cc) Matt Lavin/Flickr