Cabbage White Butterfly: All You Need to Know in a Nutshell

The Cabbage White Butterfly, a common sight in gardens and fields, is an intriguing creature with unique features.

These medium-sized butterflies are predominantly white, sporting dark wingtips and, depending on their gender, one or two black spots in the center of their forewings.

Cabbage White Butterflies have an interesting relationship with plants, particularly those in the cabbage family, including broccoli and cauliflower.

Although they can be considered minor pests in home gardens, their vibrant presence is a sign of the transitioning seasons, as they emerge from their chrysalises early in the year.

Cabbage White Butterfly: Identification and Description

Physical Attributes and Markings

The Cabbage White Butterfly is a medium-sized butterfly with a wingspan of approximately 2 inches. Here are some notable physical features:

• Color: White or yellow-white
• Dark wingtips
• Strong fliers
• Nectar at various flowers

One key trait to identify Cabbage White Butterflies is the markings found on their wings.

Both male and female have dark wingtips, but there are variations in the number and size of black spots in the center of the forewings.

Male vs Female

Distinguishing between male and female Cabbage White Butterflies is relatively simple, with the primary difference being the number of black spots found on their wings.

In addition, the black spots on a female’s wings tend to be slightly more prominent than those on a male’s wings.

Additionally, the dark markings on the butterflies may be fainter in spring compared to other seasons.

By understanding the physical attributes and markings of the Cabbage White Butterfly, distinguishing between males and females becomes much easier.

Male Cabbage White

Life Cycle and Reproduction

Eggs

Cabbage white butterfly (Pieris rapae) females lay their eggs on host plants, often from the cabbage family.

The eggs are tiny, oval-shaped, and yellowish-white in color.

These butterflies typically have a preference for broccoli, cauliflower, and cabbage plants. A single female can lay up to 300 eggs during her life¹.

Larva

Once hatched, the green caterpillars, also called cabbageworms, feed on the host plants’ leaves.

They have yellow lines on their top and sides, which help them blend in with the vegetation². Here are some key characteristics of the larva:

• Green color
• Yellow lines along the top and sides
• Feeds on cabbage family plant leaves

The caterpillar stage lasts for about two weeks before they turn into pupae.

Pupa

The pupa, also referred to as a chrysalis, is the transformational stage of the life cycle.

The cabbage white butterfly forms its pupa typically on the underside of leaves or stems of the host plant.

During this stage, the caterpillar transforms into an adult butterfly. It usually takes around 10 days, depending on environmental conditions.

Adult Butterfly

Once fully developed, the adult cabbage white butterfly emerges from the pupa. The adults have a wingspan of approximately 2 inches³.

They are white with dark wingtips, and females have two black spots while males have one².

Comparison Table: Female vs. Male Cabbage White Butterfly

These butterflies are strong fliers and are known to nectar at a variety of flowers.

The complete life cycle from egg to adult typically takes 3-4 weeks, depending on weather conditions and available food sources³.

Habitat and Distribution

The Cabbage White Butterfly is commonly found in gardens and various regions around the globe.

It is native to Europe, Asia, and North Africa but has also spread to other areas, including North America, Australia, and New Zealand.

This butterfly thrives in diverse habitats, from rural to suburban settings.

Cabbage White Butterflies are particularly drawn to regions where cabbage family plants, such as broccoli and cauliflower, are present.

Here’s a breakdown of their distribution:

• Europe: Native region, widespread across the continent
• Asia: Native to many parts, including North Africa
• North America: Introduced species, now common in both the United States and Canada
• Australia and New Zealand: Introduced species, established in various areas
• Habitats: Gardens, suburbs, and agricultural environments

Their adaptability permits them to flourish in various environments. As a result, they are now considered a widespread species, appearing in gardens and suburbs around the world where suitable habitat exists.

Impact on Crops and Gardens

Common Host Plants

Cabbage white butterflies (Pieris rapae) can be a nuisance for gardeners and farmers.

Their larvae primarily infest plants from the Brassicaceae family, which includes:

• Cabbage
• Broccoli
• Cauliflower
• Kale
• Mustard

Symptoms of Infestation

Gardeners and farmers can identify cabbage white infestations by:

1. Holes in leaves: The larvae feed on the plant leaves, leaving irregular holes behind.
2. Green worms/caterpillars: The cabbage white larvae, also known as green worms or cabbage worms, can be found on the host plants.

Natural Predators

There are several natural predators that help control cabbage white butterfly populations:

• Birds: Many species of birds enjoy feasting on cabbage white larvae.
• Parasitic wasps: These wasps lay their eggs inside cabbage worms, eventually killing the larvae.
• Ladybugs: Both adult ladybugs and their larvae feed on cabbage white eggs.

To summarize, cabbage white butterflies are common pests that affect Brassicaceae plants in gardens and crops.

Their larvae create holes in leaves and can damage plants, but several natural predators can help keep their numbers in check.

Management and Prevention Strategies

Cultural Control

• Remove outer leaves: Regularly inspect and remove infested outer leaves from cabbages and other cole crops. This helps reduce the overall population of imported cabbageworm larvae.
• Plant strong-smelling plants: Consider companion planting with strong-smelling plants like garlic, horseradish, and radish. The odor may deter the Cabbage White Butterfly.
• Floating row cover: Use floating row cover or horticultural fleece to protect crops and prevent the butterfly from laying eggs. Ensure it is properly fixed and remove it during pollination.

Chemical Control

• Insecticides: Use selective and less harmful pesticides such as Bacillus thuringiensis (Bt) or neem oil. Bt, a naturally occurring soil bacterium, is safe for beneficial insects and specific to caterpillars. Read the labels carefully and follow the instructions.

Biological Control

• Attract birds: Encourage birds in your garden by providing nesting sites and fresh water. Birds can be natural predators of the small white or small cabbage white caterpillars.
• Nectar plants: Plant flowers that attract parasitic wasps, hoverflies, and other beneficial insects that feed on imported cabbageworms.
• Avoid slug/snail attractants: Refrain from planting slug and snail attractants (e.g. bok choy, sprouts) near cabbage fields as they also attract Cabbage White Butterflies.

Remember to always consider the site-specific conditions, the scale of the problem, and potential non-target effects before choosing a management strategy.

Combining methods can help minimize the dependence on chemicals and promote a healthier environment.

Economic Impact of the Cabbage White Butterfly

The small cabbage white butterfly, Pieris rapae, is an extraordinarily abundant migratory pest of cabbage that inflicts significant damage globally.

This butterfly’s larvae exhibit an exceptional relative growth rate (RGR), which is the ratio of the daily increase of biomass to total biomass.

The RGR of P. rapae on cabbage during its larval period is notably higher than that of all other insect-plant pairs tested.

Specifically, its biomass more than doubles each day, a rate that is significantly faster than most insect-plant pairs.

This rapid growth rate is a primary reason for its widespread pest status, accompanied by its abundance and migratory nature.

The severe damage caused by P. rapae larvae on cabbage contrasts sharply with the general low levels of herbivory observed in various terrestrial ecosystems.

In many instances, the damage inflicted by these larvae can lead to up to 80% of cabbage heads becoming unmarketable.

This has significant economic implications for farmers and the agricultural industry, especially given the butterfly’s widespread distribution in temperate regions globally, including Europe, North America, North Asia, East Asia, Australia, and New Zealand.

The butterfly’s high level of herbivory on cabbage is neither due to the cabbage being a cultivated variety nor because the tests were performed in cultivated fields.

Both wild and cultivated varieties of cabbage suffer severe damage.

Furthermore, the global pest status of this insect cannot be attributed to a lack of natural enemies, as both its original and invaded regions have numerous predators and parasitoids.

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