Fortunately earwigs, small brown soft-bodied fellows with large pincers protruding from their backsides, tend to be a temporary problem, but when they invade your garden, destroying flowerbuds and leaves and depositing droppings in your lettuce, ANY visit is too long! A compilation of ways to fight back from GardenWeb users.
We are punching small holes with a leather punch in the lids of margarine containers....we add some water, a few drops of tuna oil from canned tuna, a drop of dish soap and a piece of fruit or something sweet. Dig the tub into the soil so lid is level with the earth and sit back and let the little fellows do themselves in.
I have had to plant things farther apart..for example my peas and favas get infested with earwigs if I plant them close together and they have lots of dark, damp places to be...I don't have half the problem if I force myself to space things out more
I read on a posting (somewhere) that earwigs can be detered from coming into the house if you sprinkle bay leaves around. I decided to try this in my pots. It worked! Now my petunias are doing nicely. All I did was sprinkle the bay leaves on top of the soil. Maybe if I break up the leaves next time the slugs won't visit either. The rough edges of the broken leaves might deter them. I imagine this may even work in the garden.
An easy way to reduce the earwig population is to take a few rolled up newspaper(s) (secured with a rubberband), wet it and leave it out overnight near your affected garden beds. In the morning dispose of the newspaper in a plastic bag, (being careful not to spill the ends or unroll the paper). It will be filled with earwigs. They love to hide in dark damp places. Secure the plastic bag so the little creeps dont escape and throw it away.
I printed out the various posts and made a mix similar to what was recommended - 1 tbsp each of vegetable oil, molasses, and soy sauce. I put some in two cans, and placed the cans in the garden. This morning, both to my horror and delight, both cans are FULL of dead earwigs!!! On one hand I'm thrilled that this method has helped me more than anything else I've tried (soap, pyrethrin, and rotenone). On the other hand, I can see that I have a large population, and will need to continue this tactic for quite some time.
It may take a few days for the mixture to "age" as mine took that long to get going last year before filling up quickly. Be sure to mix the two ingredients good as oil and soy sauce separate into layers. I mix a batch in a separate container first then pour it into the yogurt cup type traps. Place traps at the base of the target plants.
A grower of show dahlias puts vaseline on the stems of her flowers to keep earwigs out!
I would be tempted to use Diatomaceous earth. The only problem is that I would not like the idea of breathing the dust, so I would wet the plants or ground first and apply it in moderation at the base of the most important plants. I saved a passion flower vine this way. I must have had the european earwigs as the leaves were indeed being chewed by them. I could watch them chewing.
And of course, there's the pick-squish-stomp method...or you can drop them into soapy water as they are caught.
Diazanon and Sevin sprays are also effective. Be sure to read and follow all package directions and cautions EXACTLY .