Common Cabbage Pests and How to Control Them

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Pest management is a crucial aspect of cabbage cultivation, as pests can cause significant losses in yield and quality. 

Common pests affecting cabbage are aphids, caterpillars, diamondback moths, flea beetles, root maggots, and slugs. Pest management strategies include cultural practices, biological control, and chemical control. 

Table of Contents

Introduction to Controlling Cabbage Pests

Cultural practices involve selecting resistant varieties, rotating crops, removing weeds and debris, and using row covers or netting. 

Biological control involves introducing natural enemies of pests, such as parasitoids, predators, and pathogens. 

Chemical control consists in applying pesticides when pest populations reach economic thresholds. Pest management should be integrated and tailored to the specific conditions of each cabbage field.

Overview Of Common Cabbage Pests

Cutworms, imported cabbageworm, cabbage looper, diamondback moth larvae, and cross-striped cabbage worms can all wreak havoc on cabbage crops. These pests can seriously harm young transplants and older plants by nibbling on their leaves.

Because many of these pests are significantly more challenging to control as large larvae, measures aimed at small larvae will always be the most successful. As a result, early detection of infestations is crucial for pest management.

Identifying Cabbage Pests

Cabbage Loopers

Cabbage loopers are among the most common pests attacking cabbage and other cruciferous crops. They are small green caterpillars with a white stripe along each side of their body. They move by arching their backs and looping their bodies, hence their name.

Cabbage loopers feed on the leaves of cabbage plants, creating irregular holes and ragged edges. They can also bore into the heads of cabbage and contaminate them with their frass (droppings). Heavy infestations can reduce the yield and quality of cabbage crops.

Cabbage loopers have a complete metamorphosis, meaning they go through four stages: egg, larva, pupa, and adult. The adult is a brownish-gray moth with a silver spot on each wing. The female moth lays eggs singly or in clusters on the underside of cabbage leaves. 

The eggs hatch in about a week, and the larvae feed for two to four weeks before pupating in a silken cocoon attached to the plant or nearby debris. The pupal stage lasts for one to two weeks before emerging as adults. There can be several generations per year, depending on the climate.

When scouting, look for newly hatched larvae on the undersides of the lower leaves. Pull back loose wrapper leaves and look for larger larvae near the base of the head. Frass (excrement) evidence near the bottom of the head aids in discovering larvae. 

Because larger loopers are more challenging to regulate, timing applications for younger larvae are critical. Be careful when using pheromone traps as they may attract additional unwanted pest guests.

H3: Imported Cabbageworms

Imported cabbageworms are among the most common pests affecting cabbage and other cruciferous crops. They are the larvae of a white butterfly with black spots on its wings.

The larvae are velvety green caterpillars with a thin yellow stripe along their backs. They’re about one and a quarter inches (3 cm) long.  

They feed on the leaves and heads of cabbage, creating holes and leaving behind frass (excrement). They can also bore into the stems and cause wilting.

The lifecycle of imported cabbageworms begins when the adult butterflies emerge in spring and lay bullet-shaped eggs on the underside of cabbage leaves. 

The eggs hatch in about a week, and the larvae feed for two to four weeks before pupating in a silken cocoon attached to the plant or nearby debris. The pupal stage lasts for one to two weeks before new butterflies emerge. 

Imported cabbageworm cause similar harm to loopers but feeds closer to the plant’s center. Larvae are frequently hidden near veins or the midrib on the underside of the leaves. Large larvae can harm young plants, resulting in large output decreases.

A tell-tale sign of their presence is the presence of white butterflies fluttering around during the day. Eggs are laid singly and can be found on any part of the plant.

Cabbage Root Maggots

Cabbage root maggots are small white larvae that feed on the roots of cabbage and other brassica crops. They can cause severe damage by tunneling through the roots and making them rot. 

The maggots are the offspring of small gray flies that lay their eggs near the base of the plants in early spring. The eggs hatch in a few days and the larvae burrow into the soil to find the roots. The maggots feed for about three to four weeks before pupating in the ground. 

The adult flies emerge in late spring or early summer and may lay more eggs for a second generation of larvae.

Aphids

Aphids are small, soft-bodied insects that suck the sap from the leaves and stems of cabbage plants. They can cause wilting, yellowing, curling, and stunting of plant growth. 

Aphids also secrete a sticky substance called honeydew, which attracts ants and can lead to the growth of sooty mold on the leaves. Aphids can reproduce rapidly and have several generations per year, and they can be winged or wingless, depending on the environmental conditions. 

Aphids overwinter as eggs on host plants or in nearby weeds. In spring, they hatch and feed on the new growth of cabbage plants. They can also spread viruses and other diseases.

H3: Cutworms

Cutworms are caterpillars that feed on the stems and roots of young cabbage plants at night. They can cause severe damage by cutting off the plant at the soil level, hence their name. 

Cutworms have many colors and patterns but are usually dull and smooth. They curl up into a C-shape when disturbed. Cutworms have a one-year lifecycle. 

They overwinter as pupae in the soil and emerge as moths in the spring. The moths lay eggs on weeds or plant debris near the cabbage crop. The eggs hatch into larvae that feed for several weeks before pupating in the soil again.

Preventing Cabbage Pests

Humans aren’t the only cabbage lovers; they’re susceptible to various pests that can damage their leaves, roots, and heads. Common cabbage pests include aphids, cabbage worms, flea beetles, root maggots, and cutworms. 

To prevent these pests from infesting your cabbage crop, you can use some of these methods:

• Choose resistant varieties of cabbage that have been bred to withstand pest attacks.
• Rotate your crops every year to avoid pest buildup in the soil.
• Cover your plants with row covers or netting to exclude flying insects like aphids and cabbage moths.
• To control pest populations, apply organic pesticides like neem oil, insecticidal soap, or diatomaceous earth.
• Handpick and destroy any visible pests or eggs on your plants.
• Encourage natural predators like ladybugs, lacewings, and parasitic wasps to feed on the pests.

Following these steps, you can protect your cabbage plants from harmful pests and enjoy a healthy harvest.

Cultural Practices

Crop Rotation

Crop rotation is one of the most effective ways to prevent cabbage pests. By changing the location and type of crops you grow each year, you can disrupt the life cycle of the pests and reduce their population. 

For example, if you grow cabbage in one area this year, you should avoid planting cruciferous crops (such as broccoli, cauliflower, or kale) for at least three years. 

This will deprive the pests of their preferred host plants and force them to look elsewhere for food.

Sanitation

Sanitation is another essential practice to prevent cabbage pests. Removing plant debris and weeds from your garden area before planting and after harvesting your cabbage crop can eliminate potential hiding places and breeding grounds for pests. 

It would be best to dispose of any infested or diseased plants as soon as possible to prevent them from spreading the pest problem to other plants.

Interrupting Pest Activities

• Other preventative measures that can help you prevent cabbage pests include using row covers to protect your plants from flying insects such as aphids and flea beetles.
• Use trap crops such as nasturtiums or radishes to lure away some pests from your main crop.
• Attract the pests’ natural enemies, such as ladybugs or parasitic wasps, to control some pest populations.
• Use organic or botanical insecticides such as neem oil or pyrethrum only when necessary, following the label instructions carefully.

Companion Planting

Companion planting is one of the most effective ways to prevent cabbage pests. Companion plants have beneficial effects on each other, such as repelling pests, attracting beneficial insects, improving soil quality, or enhancing flavor. Some of the best companion plants for cabbage are:

• Alliums: Garlic, onion, leek, and chive are all members of the allium family that can deter cabbage worms, aphids, and root maggots with their strong scent.
• Herbs: Dill, sage, thyme, mint, rosemary, and oregano are some herbs that can repel cabbage moths and other pests with their aromatic oils. They also attract beneficial insects like ladybugs and parasitic wasps that prey on cabbage pests.
• Flowers: Marigold, nasturtium, calendula, and zinnia are some of the flowers that can add color and beauty to your cabbage patch while also repelling pests and attracting pollinators and predators. 
• Marigolds can deter nematodes and root maggots with their root exudates. Nasturtium can lure aphids away from your cabbage. Calendula can trap whiteflies with its sticky stems. Zinnia can attract hoverflies that feed on aphids.

Companion planting is a natural and organic way to prevent cabbage pests without using harmful chemicals or pesticides. You can enjoy a healthy and bountiful harvest by choosing the right plants to grow alongside your cabbage.

Helpful Tip: Sunflowers can attract flea beetles, so plant them far from your cabbage crop

Biological Pest Control

Biological pest control uses natural enemies or agents to reduce the damage caused by insects such as cabbage worms, loopers, larvae, and flea beetles. Biological pest control can be an effective and environmentally friendly way to protect cabbages from insect damage.

Beneficial Insects

Beneficial insects are those that provide some benefit to humans or the environment, such as pollination, decomposition, or predation. Predatory insects are a type of beneficial insect that feed on other insects that may harm crops or plants. 

For example, predatory insects can help control cabbage pests such as aphids, caterpillars, and whiteflies by eating or parasitizing them. Some common predatory insects that can be used for biological pest control of cabbage pests are ladybugs, lacewings, hoverflies, and parasitic wasps.

Bacillus Thuringiensis (Bt)

Another example of biological pest control is the use of Bacillus thuringiensis (Bt), a soil-dwelling bacterium that produces toxins that are lethal to certain insects. 

Bt. can help control caterpillar pests that feed on crops such as corn, cotton, cabbage, and tomatoes. Bt toxins are specific to the target insects and do not harm beneficial insects, animals, or humans. 

Bt. can be applied as a spray or incorporated into genetically modified crops expressing the toxins in their tissues.

Bt. beneficial insects such as bees and butterflies are safe for humans and other animals.

Chemical Pest Control

Chemical pest control uses synthetic or natural substances to kill or repel unwanted insects, rodents, weeds, fungi, and other pests. Chemical pest control can be effective and convenient, but it also poses risks to human health and the environment. 

Organic Pesticides

Organic pesticides are natural substances that can help control pests without harming the environment or human health. 

Some of the best organic pesticides for cabbage crops are:

• Bacillus thuringiensis (Bt): This bacterium produces toxins that kill caterpillars, such as cabbage worms and loopers. Bt. is sprayed on the plants and ingested by the pests, causing them to stop feeding and die. Bt. is selective and does not harm beneficial insects or mammals.
• Neem oil: This is an extract from the seeds of the neem tree, which has insecticidal and fungicidal properties. Neem oil can repel and kill various pests, including aphids, whiteflies, spider mites, scales, and fungal diseases. Neem oil is applied as a spray or a soil drench.
• Pyrethrin: This natural compound extracted from chrysanthemum flowers acts as a nerve poison for insects. Pyrethrin can kill many pests on contact, including aphids, caterpillars, beetles, flies, and thrips. Pyrethrin is biodegradable and has low toxicity to mammals.
• Spinosad: This is a substance derived from a soil bacterium that affects the nervous system of insects. Spinosad can control caterpillars, leafminers, thrips, fire ants, and other pests. Spinosad is selective and does not harm beneficial insects such as bees or ladybugs.

When using organic pesticides for cabbage crops, following the label instructions carefully and applying them at the right time and frequency is essential. 

Some organic pesticides may need to be reapplied after rain or irrigation. Rotating different types of pesticides is also advisable to prevent pest resistance.

Combining Chemical Pest Control with Other Measures

Organic pesticides can be combined with other methods of pest management for cabbage crops, such as:

• Intercropping involves planting flowers or herbs that attract natural enemies of pests or repel pests themselves. For example, planting buckwheat or sweet alyssum can attract predatory wasps that feed on aphids. Planting garlic or marigolds can deter some insects from attacking cabbage.
• Row covers: Use lightweight fabrics to protect the plants and prevent pests from reaching them. Row covers can be used during the early stages of growth or when pest pressure is high. 
• Handpicking involves manually removing pests from the plants or cutting off infested parts. Handpicking can be effective for small-scale gardens or low-pest populations. Handpicking should be done regularly and carefully to avoid spreading diseases.

Organic pesticides can help protect cabbage crops from harmful insects without compromising their quality or safety. Using organic pesticides and other cultural practices allows cabbage growers to enjoy a healthy harvest of this nutritious vegetable.

Synthetic Pesticides

Synthetic pesticides are chemicals designed to kill or control pests such as insects, weeds, fungi, rodents, and bacteria. They can help protect crops and gardens from damage and disease but also pose risks to human health and the environment if misused. 

Therefore, it is essential to use synthetic pesticides responsibly and follow these guidelines:

• Read and follow the label instructions carefully before applying any pesticide. The label contains information on how much, how often, and where to apply the pesticide, what protective equipment to wear, and how to dispose of the leftover product and containers.
• Choose the right pesticide for your specific pest problem. Do not use more than recommended or mix different pesticides unless the label instructs. Using too much or the wrong pesticide can harm beneficial organisms, cause pest resistance, or contaminate water sources.
• Apply pesticides only when necessary and at the right time. Avoid spraying when it is windy, rainy, or hot, as this can reduce the effectiveness of the pesticide and increase the risk of drift or runoff. Monitor your pest situation regularly and use non-chemical methods such as cultural practices, biological control, or mechanical removal whenever possible.
• Store pesticides safely and securely away from children, pets, and food. Please keep them in their original containers with labels intact, and do not transfer them to other containers that might be mistaken for something else. Store them in a cool, dry place that is well-ventilated and locked.
• Dispose of pesticides properly according to local regulations. Do not pour them down drains or toilets or throw them in the trash. Contact your local waste management authority or extension service for advice on disposing of unwanted pesticides or empty containers.

FAQs on Common Cabbage Pests and How to Control Them

In Summary

You can grow fabulous cabbages by taking the appropriate measures to control pests early. Beneficial insects are very effective in managing infestations as they reduce population early on.

An integrated pest management (IPM) approach combines biological, cultural, physical, and chemical methods to minimize economic, health, and environmental risks. Use a system that prevents pest problems before they occur, using pesticides only as a last resort.

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