What Will Kill Cutworms: Effective Solutions Explained

Cutworms are a common pest that plagues gardens and agricultural fields worldwide. These nocturnal caterpillars, named for their ability to “cut” down seedlings at their base, can cause significant damage to crops in a short period. As their infestations continue to pose a challenge for farmers and gardeners alike, finding effective methods to combat them becomes increasingly important.

One way to control cutworms is by using Bt corn, a type of genetically-engineered corn that produces a toxin lethal to these pests. Bt corn has been shown to specifically target the corn rootworm larvae, without harming other insects like cutworms or beneficial species source. Another method is the use of DDT, a synthetic chemical insecticide, which can be successful in killing cutworms when applied as a dust on the affected area source.

While some of these methods may prove effective in controlling cutworms, it’s important to consider the potential impact on the environment and balance pest control with the preservation of beneficial species. As research continues, the development of more environmentally-friendly solutions could help maintain healthy ecosystems while mitigating the damage caused by these prevalent pests.

What Are Cutworms

Cutworms are larvae of several species of nocturnal moths, which belong to the family Noctuidae. These pests are typically found in gardens and crop fields, causing extensive damage to the plants. Cutworms are known for their habit of cutting through the stems of seedlings or young plants, effectively killing them.

There are different types of cutworms, such as the western bean cutworm, found primarily in dent corn in Nebraska, and the pale western cutworm that targets grain crops in western regions. These pests have varying degrees of severity and impact on agriculture, depending on the species and location.

Cutworms have a cylindrical shape, and their soft bodies vary in color, usually in shades of gray, brown, or green. They grow to about 1-2 inches in length and spend most of their time hidden in the soil during the day, emerging at night to feed on plants.

The life cycle of cutworms begins with adult moths laying eggs on plant leaves or stems. After hatching, the larvae feed on plants for several weeks before pupating in the soil. They emerge as adult moths to continue the cycle, with some species having multiple generations in a year.

Effective control measures for cutworms include:

  • Monitoring the presence of larvae and adult moths in the field or garden
  • Providing proper cultural practices, such as maintaining good soil health and crop rotation
  • Utilizing biological control agents, such as predators and parasites, to reduce cutworm populations
  • Applying chemical insecticides or organic alternativesproperly and at the right stage of the cutworm’s life cycle
What will kill cutworms?

Identification and Damage

Physical Characteristics

Cutworms are caterpillars belonging to the moth family Noctuidae. They have a soft, plump body with a distinct head capsule and can grow up to 2 inches (5 cm) long. The color varies between species and can range from brown, green, gray, to black. Some species may have lateral stripes or patterns on their body. Most cutworms are nocturnal pests, hiding beneath the soil during the day and emerging at night to feed on plants.

Damage Signs

The damage caused by cutworms mainly revolves around their feeding habits. These pests are notorious for attacking the stems of young plants, causing them to wilt and eventually die. A few common signs of cutworm damage include:

  • Seedlings that are cut near the ground level, often with their damaged stems lying beside the soil
  • Circular holes in the leaves of young plants, which can resemble various types of feeding damage
  • Presence of cutworm larvae on or near affected plants, especially during nighttime hours
  • Small to large areas of dead or stunted plants in a field or garden, suggesting a larger infestation

Controlling cutworm populations usually involves implementing preventive measures, such as using biological control agents like predatory carabid larvae and sphecid wasps, keeping a balanced ecosystem in your garden, or using targeted pesticides when needed. Remember to properly identify the presence of cutworms based on their physical characteristics and the damage signs they leave behind to ensure effective control measures.

Damaged rose bush

Prevention and Control

Proper management of cutworms is essential to prevent damage to plants and crops. In this section, we will discuss various methods to control and prevent cutworm infestations, including cultural, biological, and chemical control methods.

Cultural Control Methods

Cultural control methods involve adapting agricultural practices to prevent cutworm infestations or minimize their impact. Some suggested control techniques include:

  • Crop rotation: Rotating crops can help break the life cycles of cutworms and reduce their populations.
  • Tilling the soil: Tilling the soil before planting exposes cutworms to predators and disrupts their life cycle.
  • Planting date adjustments: Delaying planting until cutworm populations have declined can reduce plant damage. However, this may not be suitable for all crops.
  • Removing plant debris: Clearing away dead plants and debris can help eliminate cutworm hiding places and reduce their populations.

Biological Control Methods

Biological control methods use natural enemies of cutworms to help manage their populations. Examples include:

  • Parasitic wasps: Some species of parasitic wasps lay their eggs inside cutworm larvae, killing them when the wasp larvae hatch and feed on the host.
  • Entomopathogenic nematodes: These nematodes can help control cutworm populations by infecting and killing the larvae in the soil.
  • Bacillus thuringiensis (Bt): This bacterium produces toxins that are lethal to cutworms when ingested, providing an effective and environmentally friendly control option.

Chemical Control Methods

Chemical control methods involve the use of insecticides to reduce cutworm populations. Some strategies for effective chemical control include:

  • Bait applications: Applying a bait mixture of an insecticide and a food attractant can help target cutworms specifically and limit exposure to non-target organisms.
  • Targeted applications: Applying insecticides directly to infested areas or to crops at critical growth stages can help manage cutworm populations and reduce plant damage.
  • Resistance management: Rotating insecticides with different modes of action can help prevent the development of resistance in cutworm populations.

It is crucial to follow local regulations and label instructions when applying chemical control methods for cutworm management. Always consider the potential impact on the environment and non-target organisms when choosing a control strategy.

Safety Measures

When using chemicals to control cutworms, it’s crucial to prioritize safety and follow proper guidelines set forth by product labels and regulatory agencies. Here are some essential safety measures to consider when applying pesticides or other treatments to protect your plants from cutworms.

First, always wear the necessary protective clothing and equipment, such as gloves, masks, and goggles, as recommended on the pesticide label. This helps to prevent direct exposure to harmful substances and reduces the risk of accidental ingestion or inhalation.

It is vital to read and understand the directions and safety measures provided on the pesticide label before use. This includes information about application rates, methods, and any required waiting periods before harvesting. Since chemicals can have negative effects on humans, animals, and the environment, adhering to the instructions ensures minimal harm and maximizes effectiveness.

When applying pesticides, consider using targeted techniques such as sex pheromone trapping technology to control specific cutworm species like the Spodoptera litura. This method can reduce pesticide usage by over 80%, resulting in a more economical, safe, and efficient control system.

Lastly, proper storage and disposal of chemicals are crucial to maintaining the safety of your household and environment. Always store pesticides in their original containers, away from food and water sources, and out of reach of children and pets. Follow the disposal instructions on the product label or consult local waste management authorities for proper disposal methods.

By following these safety measures, you can effectively control cutworms while minimizing risks to yourself and the environment.


Cutworms can cause significant damage to various crops, and controlling their population is essential for maintaining a healthy agricultural environment. One effective method for controlling cutworms is the use of specific chemical poisons in bait applications. However, it is crucial to consider the impact of these chemicals on other organisms and the environment.

In addition to chemical control, other factors, such as rainfall, can also play a part in regulating cutworm populations. Research has indicated that daily rainfall can kill 1% of surviving first- and second-instar larvae. This highlights the importance of considering environmental factors in cutworm management strategies.

Starvation experiments have also revealed that cutworm larvae starved for 10 days before feeding can meet unfavorable conditions that kill approximately 80 to 90% of them. This information can potentially contribute to developing better control methods for cutworms.

To summarize, effective cutworm control methods include the use of chemical poisons, consideration of environmental factors such as rainfall, and exploring more sustainable options that leverage the larvae’s vulnerability to starvation. Implementing a multi-faceted approach will help ensure successful management of cutworm populations and protection of valuable crops.

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