Here's a link to UC Davis IPM on Earwigs.
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74102.html from the same link:
MANAGEMENT
Management of earwigs requires an integrated program that takes advantage of their habitat preferences. As moisture-loving insects, earwigs would not normally thrive in California�s arid climate without the moisture and shade provided by the irrigated garden. Where earwigs are a problem, consider reducing hiding places and surface moisture levels. Initiate a regular trapping program. If these measures are followed, insecticide treatments should not be necessary.
Trapping
A key element of an earwig management program is trapping. Scatter numerous traps throughout the yard. Traps can easily be hidden near shrubbery and ground cover plantings, or against fences. A low-sided can, such as a cat food or tuna fish can, with 1/2-inch of oil in the bottom makes an excellent trap. Fish oil (e.g., tuna fish oil) is very attractive to earwigs or vegetable oil with a drop of bacon grease can be used. Dump captured earwigs and refill cans with oil. Other common types of traps are a rolled-up newspaper, corrugated cardboard, bamboo tube, or short piece of hose. Place these traps on the soil near plants just before dark and shake accumulated earwigs out into a pail of soapy water in the morning. Continue these procedures every day until you are no longer catching earwigs.
Following info is from Sunset Western Garden Book Problem Solver.
Try making earwig traps by placing damp, loosely rolled-up newspapers on the ground near the
plants. The insect will crawl into the rolls, which you can then discard; Or fill a low-sided can such as a cat-food can, with 1/2 inch of vegetable oil and place on the ground.
If using commercial earwig traps from garden centers, place them near areas where earwigs are likely to be... in woodpiles, under wooden stairways or deck, near old wooden fences and arbors.
For severed infestations, spray oil and around
plants with an isecticide containing diazinon in the lage afternoon or evening, according to directions on the label.
