I haven’t had any problems with pests on my cabbage for a long time, and I don’t use any chemicals to kill them.

For several seasons now, I have been successfully using a homemade natural remedy, which consists entirely of natural ingredients.

Here is the composition that I use to control cabbage pests and other crops.
I add 5 tablespoons of mustard powder, 1 tablespoon of ground red hot pepper, and 2 tablespoons of baking soda. The total amount of ingredients is 8 tablespoons.

First, I pour 5 tablespoons of mustard powder into a liter jar and fill it with hot water at a temperature of about 50 degrees.
After thoroughly mixing, I let the mixture steep for about three days. Then I mix the mustard powder infusion with 8 liters of water in a bucket.
I add 1 tablespoon of red hot ground pepper and 2 tablespoons of soda ash.

I thoroughly mix all the ingredients and begin treating the cabbage or other crops. After a couple of hours, the plants are no longer infested with slugs, fleas, or caterpillars.
This treatment is usually sufficient for a month. In case of heavy rain or if signs of pest infestation appear, I repeat the treatment.
P.S. I recommended my friend from a neighboring city to use this composition to treat potatoes.
She followed my advice and never had a Colorado potato beetle again. Maybe this will work for someone else, too.