Answer: Rather than earwigs, I would suspect slugs. They enjoy delphiniums, and work at night so you would not see them. Slugs can be controlled by hand picking at night, by setting out saucers of beer or commercial slug traps, or by sprinkling diatomaceous earth on the soil surface immediately around the plants. There are also commerical slug baits. If you still think it is earwigs they can be trapped in saucers of vegetable oil (each morning strain it and reuse it), or in overturned pots or cardboard tubes filled with dampened paper or similar material.
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