Not long after the earwigs went to town in the greenhouse, they started causing havoc in the rows. As I’ve been looking for ways to control the damage, I’ve often read cautions that the insects are most often beneficial, or at least, harmless. This includes the book I most often consult for organic ways to deal with pest and disease problems. (I would agree with this – is so interesting that neither Matt nor I have had this type of problem with earwigs before. But we clearly have a serious imbalance and need to deal with it.)
Young kale, some lettuce, about 90% of the just-sprouting radishes, and the strawberries were really hit hard over the course of a day or so, and I knew we had to do something before planting replacements, or anything new. So, I decided to trial 3 methods of trapping earwigs at once, and see which worked the best. The ideas came from various resources.
What I learned: There are WAY more earwigs here than I realized there were. Loads. Tons.
The three traps I am using are: rolled up newspaper, damp newspaper stuffed into a container, and a pitfall trap with bait.
For all of the traps – place them in areas where you already have damaged plants.
Damp newspaper in container (3rd place)
How to: dampen crumpled newspaper and stuff it into an old container of some sort (planter, etc.) I used large yogurt containers. Prop it up on a rock or stick so the pests can get into it. I put a large rock on top to keep it in place. When you check the trap, pull the newspaper out over a bucket with a couple inches of soapy water in the bottom (dish soap works fine). I was surprised that these didn’t work for me; I only found one slug underneath, but no earwigs in the three traps that I set.
Rolled up newspaper (2nd place)
How to: dampen a sheet of newspaper, roll it up, set it out on the ground. I weighted it with a rock since it gets breezy here. When you check the trap: shake the newspaper over your bucket of soapy water. For me this worked best in the morning, before the paper dried up and the earwigs fled elsewhere.
Far and away what has been working the best is…
Baited pitfall trap (Winner)
How to: Use old containers that will hold liquid (butter tubs, yogurt cups, etc.) The bait is a combination of water, some soy sauce, and a dab of molasses, with a thin layer of vegetable oil carefully floated over the top. I mixed up a batch of bait, sunk the containers out in the garden with the lip at ground level, then went back out and poured an inch or so of the liquid into the bottom. I used a small container to add a little bit of vegetable oil over the top, so that it formed a more-or-less continuous thin layer. There have been loads of earwigs in every trap each day, although I haven’t had to empty them yet (today is the third day). The only “con” is that a few spiders and other non-earwig-insects have also been trapped.
Organic Gardenig FAQ 