Cutworms are the larvae (caterpillars) of several species of night flying moths. They hide in soil or under leaf litter, feeding on leaves and stems of crops and other plants at night.
Cutworms are fairly common and can cause a lot of damage, often cutting young plants or seedlings straight down to ground level. I guess that’s how they get their rather cruel name. When alarmed they curl into a C-shape, my personal observation is they have very sticky feet, making them difficult to pick off plants.
I find cutworms quite often in the soil, usually in spring. So far I have been lucky with regards to them causing any real problems.
One time they took a shine to the leaves of my onions, chewing neat circular holes and cutting off the pointy tips. The bulbs were fine so no real harm done. I wasn’t sure what was causing it at first so I did a bit of investigating to see what it could be, I found the culprits way down inside the hollow leaves, complete with lots of green poop. Nice.
Gardening organically means I’m always going to have the odd ‘pest’ problem here and there, that’s how it goes. I don’t use nasty chemical sprays, my preferred method of natural control is keeping a close eye and removing any I see from the soil by hand. Cutworms have many natural predators including wild birds and wasps that depend on them to feed their young.