What Is a Cabbage Worm?

A cabbage worm typically refers to the larva of a moth or butterfly. It gets its name from its tendency to eat a number of plants from the cabbage family. A few types of cabbage worms can be found throughout the world, and each one has different characteristics. These pests can often be controlled by either manually removing them from the plants, or spraying the plants with an organic fertilizer.

In their juvenile stages, certain types of moths or butterflies can cause major damage to plants of the cabbage family. These larvae are often aptly referred to as cabbage worms. Besides cabbage, larvae worm will also feed of other cole crops, including Brussels sprouts, broccoli, and cauliflower. Collard, turnip, and mustard greens are also sometimes at risk of a cabbage worm infestation.

The imported cabbage worm is one of the most common types of cabbage worms. It is bright green with fine fuzz on its body. This caterpillar can be found in many parts of Europe and North America, and it primarily feeds on cabbage, cauliflower, and broccoli.

Cabbage loopers are another type of cabbage worm that can be found in North America. These can be identified by the prominent white stripes running down the length of their otherwise green bodies. Similar to an inchworm, when these caterpillars move, their bodies form a loop. These larvae have been known to feed on plants outside of the cabbage family, such as tomato and cucumber plants.

The cabbage webworm is a type of cabbage worm that is native to parts of Europe and Asia. Over the years, however, it has migrated, and it can also be found in many southern states in the United States. These larvae are yellow-gray in color with dark stripes on their bodies.

Another common type of cabbage worm is the larva of the diamond back moth. This smooth green caterpillar is considered to be a leaf miner. This means that the smaller larvae tunnel themselves into the leaves of plants, leaving a distinct visible line on the outside of the leaf. Larger larvae, on the other hand, will consume large chunks of the leaves. Although these are more likely to be found in the tropical regions of the world, it may be found in more temperate climates as well.

It typically does not take many cabbage worms to destroy a crop, as just a couple can destroy a plant. Signs of a cabbage worm infestation are usually quite apparent. There may be large holes in the leaves of the plants, and these caterpillars may be visible on the undersides of the leaves.

Minimizing the damage caused by these caterpillars in a cabbage garden is important for a healthy crop. Some gardeners who grow cabbage stretch sheer nylon stockings over the cabbage heads, for instance. This will help protect the plants, since the caterpillars can not get through the fabric easily.

All garden plants should be inspected frequently for signs of a garden pest infestation. Manually removing cabbage worms can be time consuming, but it is a good start to getting rid of these pests. Some organic pesticides can also be used to get rid of cabbage worms. Bacillus thuringiensis, or Bt, is an organic insecticide made from a type of bacteria. Although it will kill most of these pests, it is still considered safe for human consumption.

A cabbage worm is the larval form of the cabbage white butterfly (Pieris rapae). These caterpillars are known for their voracious appetite for brassicas, a plant family that includes cabbage, broccoli, and kale. They are typically velvety green with faint yellow stripes, allowing them to blend seamlessly with the leaves they feed on.

Cabbage worm damage is characterized by irregular holes in the foliage of brassica plants. As they feed, they create large, ragged holes, starting from the outer leaves and moving inward. You may also notice dark green frass (caterpillar droppings) on the leaves, which is another telltale sign of their presence.

Natural predators of cabbage worms include birds, spiders, and beneficial insects such as ladybugs, lacewings, and parasitic wasps. According to the University of California Statewide Integrated Pest Management Program, these natural enemies can significantly reduce cabbage worm populations in gardens and farms without the need for chemical interventions.

Cabbage worms are not directly harmful to humans; they do not bite or sting. However, their feeding can significantly damage crops, potentially affecting food supply and agricultural economy. Ingesting them accidentally with vegetables is harmless, but it's advisable to wash produce thoroughly to remove any insects or residues.

Organic control methods for cabbage worms include handpicking the larvae from plants, using floating row covers to prevent butterflies from laying eggs, and applying Bacillus thuringiensis (Bt), a natural soil-dwelling bacterium that is toxic to caterpillars when ingested. Companion planting with herbs like thyme and mint may also deter cabbage worms.

Understanding the cabbage worm's life cycle is crucial for effective control. They go through several stages: egg, larva (cabbage worm), pupa, and adult butterfly. Interrupting this cycle, especially before they become reproducing adults, is key. For instance, removing eggs and larvae reduces future populations, while timing Bt applications to target the vulnerable larval stage increases effectiveness.