posted 4 years ago
This spring I had an unprecedented plague of cutworms that were mowing down all my seedlings. I had to go out in the mornings and evenings to hand pick them; we caught over sixty cutworms, with more to go. I'd heard that cornmeal attracts and kills the worms because they can't digest it. So I put piles around, but didn't feel very confident that it would actually kill them. Instead, I used them to make collecting them easier. It certainly did attract them.
I also decided to run an experiment. I put cutworms in two containers with seedling plants (weeds), and put cornmeal in one container. In the container without the cornmeal, the plants all got eaten and had to be replaced several times. In the one with the cornmeal, no plants were eaten. After I week, we dumped them out and counted them. Most of the cornmeal fed cutworms still seemed fine, but one was swollen and sluggish.
So MAYBE cornmeal isn't good for cutworms but it does not outright kill them. It certainly does work as an attractant/ distractant to protect seedlings.