Identification
Cutworms are smooth-bodied caterpillars that grow up to 2 inches long. They are typically gray, brown, or green with faint striping or spotting. These larvae curl into a C-shape when disturbed. The adult form is a moth with a wingspan of 1-1.5 inches, often brown or gray with subtle markings. Cutworms are found worldwide and thrive in agricultural fields, gardens, and turfgrass environments.
Lifecycle & Reproduction
Cutworms undergo complete metamorphosis. Females lay eggs on plant stems, leaves, or in soil debris. Eggs hatch in 3-5 days, and larvae go through multiple instars over 3-4 weeks before burrowing into the soil to pupate. The pupal stage lasts 2-4 weeks before adult moths emerge. Several generations can occur in warm climates.
Habits, Diet & Behavior
Cutworms are nocturnal feeders that sever young plants at the base, cutting them off at ground level. Some species climb plants to consume leaves and buds. They primarily feed on vegetables, grains, and flowers. Larvae remain hidden in the soil or under plant debris during the day, emerging at night to feed.
Where You’ll Find Them / Typical Locations
Cutworms are found in gardens, crop fields, and grassy areas. They hide in the soil, mulch, or under plant debris. They are especially prevalent in newly tilled soil and areas with abundant organic matter.
Threats & Danger
Cutworms can decimate young crops and garden plants by cutting stems at the soil line. They are particularly damaging to seedlings, causing significant losses in vegetable and grain production. Their feeding weakens plants, leading to reduced yields and plant death.
Prevention
- Remove weeds and plant debris to reduce egg-laying sites.
- Use collars around seedlings to prevent larvae from reaching stems.
- Encourage natural predators like birds, toads, and parasitic wasps.
- Till soil before planting to disrupt overwintering larvae and pupae.
- Apply beneficial nematodes to target soil-dwelling larvae.
Signs of Infestation
- Severed seedlings at the soil line.
- Wilted or missing young plants.
- Presence of curled caterpillars in soil near damaged plants.
- Irregular holes in leaves or stems of larger plants.
- Increased sightings of adult moths around light sources at night.
How to Get Rid of It
- Handpick and remove larvae from soil in early morning or evening.
- Apply diatomaceous earth around plant bases to deter feeding.
- Use insecticidal soap or neem oil to target young larvae.
- Introduce beneficial insects like ground beetles and parasitic wasps.
- Apply targeted insecticides labeled for cutworm control in severe cases.