Earwigs love to nest in -- and ruin -- my ripening grapes. I don't have as many this year because they bloomed early and frost hit some of the blossom. I also deeply mulched the grapes this year so I wouldn't have to water them as often. The little earwig traps I bought a couple of years ago would be lost in it.
I've been eating tall tubs of Astro yogurt all summer. I kept three out of the blue box to make earwig traps. If they didn't work, I could always toss them back into the blue box.
The trap needs a way for the earwigs to get in, the impossibility that they can get out again, and a bait to draw them in the first place. A bait that they drown in keeps them from getting out. They like beer and liquid detergent with a scent also helps draw them. The detergent assures a drowning.
I drilled four or five 1/4" holes in the top inch of yogurt container. The lids go back on to keep out the rain and bigger vermin. The earwigs will crawl through the holes and drop into the bail solution. Every few days I can remove lids and empty out dead earwigs and spent bait.
I had some very old near-beer sitting around. It's the hops and malt that draws the earwigs, not the alcohol, so that was fine to use. I had picked up a couple of detergent jugs early in the summer with push-spigots on them to replace my older outdoor sink water supplies. Rinsing them out, I got a fair amount of diluted detergent which I stashed in another tall yogurt container. I mixed the near-bear, detergent, and water in 64 oz. jug and now have a good month's supply of earwig bait.
I nestled the traps in the mulch under spans of vine that had grapes growing. I've been removing earwigs every few days since and the grapes still look healthy.
Everything I've used in the traps has been diverted from the waste stream.