Cutworms

Cutworm

Cutworms are a common problem in gardens. You may have fallen prey to their sneaky ways.  They do their damage at night and rest in the day.  You know that cutworms have been in your garden when you find the your seeding cut off at the soil line.  There are more than one type of cutworm though and they eat at the plants in different ways.  We will explore these crawly creatures and find out about their habitat and how to control them.

Cutworms are from the Lepidoptera order which is moths and butterflies.

Cutworms are from the family Noctuidae. This is a family of moths that is active at night and is a very large insect family. These moths are attracted to lights at night.

Cutworms are grayish black, dingy and smooth skinned.  They can reach up to 1 1/2 inches in length. The cutworms curl up tightly into a C shape when disturbed.  The adults are a grayish brown dingy moths, marked with dark or light spots on their wings. Their wing span is 1 to 2 inches.

The four major group of cutworms are based on habitat and feeding behavior.

  1. Tunnel Dwellers – These cutworms lop off a young plant at the soil surface then pulls it into the the tunnel and eats it. One example is the Black cutworm.
  1. Subterranean Cutworms – These sneaky little guys go undetected very easily as they feed on the roots and underground stems of plants. You may not notice that your  plant has been attacked until it is wilted or dying. The Pale Western Cutworm is an example here.
  1. Surface Feeders – This is the bandit that you think of typically when you think of a cutworm.  He cuts off the tender young plants right at or below the soil line. The cutworm does not eat much of the plant, just enough to sever the plant. The Army Cutworm is an example of the surface feeder.
  1. Climbing Cutworm – These cutworms feed on young leaves, vegetables, buds and herbaceous plants.  They eat the young part of the plant and then move on to greener pastures.  The Variegated Cutworm is a climbing cutworm.

Control

Rake around damaged plants in a 12 inch radius to find cutworms. Destroy the cutworms after finding them.

Put birdbaths in your yard in close proximity to your garden as the birds will consume the cutworms.

Make cutworm collars to put around new transplants.  Toilet paper rolls and paper towel rolls are a good choice.  Make sure they are 4 inches long and insert them 2 inches into the ground.  You can also use metal, aluminum foil or plastic in the same fashion to protect your plants.

Do not use mulch until you have solved your cutworm problem as they like to hide under debris in the day.

Plant flowers and herbs for the wasps which are natural predators.

If you have had an existing cutworm problem in an area wait to plant a cover crop until you have the cutworms under control.

Biorationals

BT (Bacillus thuringiensis var. kurstaki)- bait cutworms by mixing bran with BT. This will lure the caterpillars away from the seedlings and let them munch on their last meal instead!  You can also mix and spray BT.

Spinosad -This is made by fermentation of a soil dwelling bacteria. Spray early morning or evening.

Azadirachtin made from the seeds of the Neem tree.  Make sure to spray early in the morning or evening.  Do not use when temperatures are over 90 degrees.

Nematodes (Steinernema carpocapsae and Heterorhabditis) – Beneficial nematodes are actually scarps and should be applied early in the morning or late in the evening.  They work against many insects and stay active in the soil for a year with hosts.

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