In limited numbers, earwigs perform a beneficial function by eating soft-bodied insects like aphids. However, they also eat soft plant parts--and if they're present in quantity, they can cause considerable damage to flower petals and corn silk. They feed at night and hide during the day under pieces of wood, flower pots, and the like. To trap them, put out loosely rolled newspaper under shrubs or among flowering plants in the evening; in the morning, dispose of paper and earwigs. Or sink low containers (such as tuna cans) into the ground at several places around the garden; add 1/2 inch of vegetable oil to each. The pests will fall in; collect and dispose of them each morning.
Chemical controls include earwig bait, which usually contains carbaryl or propoxur. Some products include fish oil as an attractant; don't use this type if there is any possibility of cats or other pets being attracted to it.