Agrotis ipsilon, Peridroma saucia
Cutworms are so named because they cut off the stems of plants at the soil level, effectively killing the plant. This feeding behavior can result in significant damage to crops such as vegetables, flowers, and ornamental plants.
Cutworms are the larvae of various species of moths in the family Noctuidae, and they are known to feed on a wide range of host plants. Some of the most common host plants include:
Vegetable crops: Cutworms are known to feed on a wide range of vegetable crops, including tomatoes, peppers, beans, corn, lettuce, and others.
Flowers: Cutworms can also feed on various flower species, including marigolds, dahlias, and petunias.
Ornamentals: Cutworms are also known to feed on ornamental plants, including shrubs, trees, and grasses.
Cutworms are a widespread insect pest found in many regions throughout the world. They are native to North America but have been introduced to other parts of the world, including Europe, Asia, and Australia.
Cutworms are most commonly found in temperate climates, but they can also be found in tropical and subtropical regions. They are most prevalent in areas with warm, moist soils, as these conditions are ideal for developing their larvae.
Cutworms are generally smooth, plump, and gray or brown in color, ranging in length from 1 to 2 inches (2-5 cm). They are typically active at night, feeding on the stems of plants and cutting them off at the soil level. During the day, they hide in the soil or under plant debris.
The larvae are often curled up when at rest, and they have a distinctive habit of cutting off plants at the soil line, which gives them their name. The adult moths are generally gray or brown in color, with mottled wings and a wingspan of about 1-2 inches (2-5 cm).
The life cycle of cutworms includes several stages, including egg, larva (cutworm), pupa, and adult moth. The following is a general overview of the life cycle of cutworms:
Eggs: The adult female moth lays eggs on leaves, stems, or in the soil near the host plant. The eggs are small and round, and they are usually laid in clusters.
Larva (Cutworm): The eggs hatch into larvae (cutworms), which are in the feeding stage. Cutworms are generally smooth, plump, and gray or brown in color.
Pupa: After feeding for several weeks, the cutworms pupate in the soil, forming a pupal case.
Adult Moth: The pupal case then transforms into an adult moth, which emerges from the soil and begins the cycle again. The adult moths are generally gray or brown in color, with mottled wings and a wingspan of about 1-2 inches (2-5 cm).
Damage and Detection
The damage caused by cutworms is primarily due to their feeding behavior.
Cutworms feed on the stems of plants, cutting them off at the soil level. This can result in the death of young seedlings and plants, as they cannot recover from the damage. The damage caused by cutworms can be particularly severe in areas with high insect populations or in areas where the host plants are particularly susceptible to damage.
In addition to cutting off the stems of plants, cutworms can also feed on the leaves and roots of plants, causing further damage and reducing the overall health and vigor of the plant.
Detection of cutworms is important for reducing the damage they cause to crops. Here are some signs to look for when monitoring for cutworms:
Cut seedlings: The most obvious sign of cutworms is the presence of cut seedlings at the soil level. If you see that young plants have been cut off just above the soil, it is likely that cutworms are present.
Larvae: You can also look for the larvae themselves.
Frass: Another sign of cutworms is the presence of frass, or excrement, near the base of the plants.
Moths: During certain times of the year, you may also see adult moths, which are generally gray or brown in color, with mottled wings.
Prevention and Control
Here are some effective methods for preventing and controlling cutworms:
Cutworm collars: One of the simplest methods for preventing cutworm damage is using cutworm collars. Cutworm collars are paper or plastic collars placed around the base of young seedlings to protect them from cutworms.
Beneficial insects: Using beneficial insects, such as parasitic wasps or lacewings, can also be an effective method for controlling cutworms. Parasitic wasps lay their eggs on the larvae of cutworms, which then hatch and feed on the larvae, reducing the population of cutworms and reducing the damage they cause to crops.
Parasitic nematodes: Parasitic nematodes are small, worm-like organisms that infect cutworms and other insect pests, killing them and reducing their population. When applied to the soil, parasitic nematodes seek out and infect cutworms and other insect pests. Once inside the insect, the nematodes release bacteria that kill the insect and provide a food source for the nematodes. Parasitic nematodes are a safe and effective method for controlling cutworms. They are specific to insect pests and do not harm beneficial insects, humans, pets, or other non-target organisms.
Setting out transplants later in the season: Cutworms are most active in the spring when young seedlings are most vulnerable to damage. By setting out transplants later in the season, when the weather is warmer, and the plants are larger, you can reduce the risk of damage from cutworms.
Damaged transplants: Inspecting and removing damaged transplants and destroying larvae hiding below the soil surface can be an effective method for controlling cutworms in the garden. Each morning, check your plants for any signs of damage caused by cutworms, such as cut seedlings at the soil level. If you find damaged transplants, remove them and dispose of them to prevent the cutworms from continuing to feed on other plants. Next, gently dig around the base of the plants to locate any cutworms hiding below the soil surface. Destroy any cutworms you find by crushing them or by placing them in soapy water.
Cultural practices: The use of cultural practices, such as mulching and companion planting, can also be effective in preventing and controlling cutworms. Mulching helps to discourage cutworms by creating a barrier between the soil and the stems of plants, while companion planting helps to lure cutworms away from your crops and onto other plants that are less desirable to them, such as tansy or spiny amaranth.
Insecticides: The use of insecticides can be an effective method for controlling cutworms. There are many different insecticides available that are specifically formulated to control cutworms, including pyrethrin and spinosad.
Tony Morris, Flickr
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.