Cutworms

By Al Lowe
Contributor

Nobody has anything really good to say about cutworms. They are ugly to look at, offensive to touch, and they are very damaging to plants. They kill all sorts of plants in your garden, and lots of other places.
Many cutworms live in the soil. They do their dirty work at night, and they often cut off young plants, just at the surface of the ground. Some of the others will climb up your plants, and eat the fruit, buds and leaves. The Armyworm (the real one, not the Tent Caterpillar) will eat all parts of the plant.
Most folk notice them in the garden. Young tomatoes or cabbages cut off at the soil line, large parts of growing plants eaten overnight. But they are also active in the lawn, the pasture, the forest. They are really bad pests in tree nurseries, where you have thousands of young plants, all the same. They will destroy pines, cedars, spruce, maples, oak, birch and more. And they also do this type of damage in the woods itself.
The cutworm itself is not very nice looking. It is plump and soft-bodied. Some species have a few hairs. Many of them will curl up in a ball if you happen to uncover them in the daytime. They live as larvae for about three weeks or so, and then they form pupae. All of this is in the ground. In a week or two, the adult emerges.
This adult is always a moth. Many of them are quite inconspicuous - dull brown or gray. But a few are really quite pretty, with brightly coloured under wings. These moths mate, and lay their eggs. Then they die. The purpose in life is over. There can be several generations in one summer. They all belong to the family Noctuidae, which means they are mostly active at night. It is a large insect family, with over 2700 species in North America.
The question is always what to do about them. In your garden, you can do quite a few things. You can spray with an insecticide. Since they are only active at night, you need to use a 'systemic' spray. You spray the affected plants, the larvae come along and eat it, and then they die.
To prevent young plants from being cut off, you can use "collars" of some kind. You can use paper cups with the bottom cut off, paper towel or toilet paper centers, or those hard peat pots. You only need to have a ring around the plant about a couple of inches below the ground, and an inch above it. As the plant grows, these will rot away.
One trick which is quite effective is to sprinkle some cornmeal around your plants. Cutworms are very fond of this, but they can't digest it, so they die.
Keep your garden free of weeds and old plants. This is always good anyway, and it will discourage the egg-laying females. Some sources recommend that you till your garden deeply as early as you can, then till it again just before you plant, only this time only down a couple of inches. This will expose the worms and the pupae to the birds and the weather.
Cutworms are preyed upon by a lot of things. Night-flying birds eat a lot of the moths. Ground birds eat the larvae which are out and about during the day. And they are eaten by toads, moles, and shrews. They are also parasitized by a number of wasps and beetles.
Once established in your yard, the cutworm can be a great nuisance, indeed. It is pretty disheartening to see your carefully tended tomato and cabbage plants lying flat on the ground - dead.
At the Ministry of Agriculture and Food, your Ag Rep can supply you with a lot more information than I can. You should make use of this valuable public service.