The cabbage white butterfly is a common sight in gardens and farms, particularly around plants belonging to the cabbage family.
These butterflies are known for their white wings with black spots.
They are notorious for the role they play as a pest among gardeners and farmers during their larval stage when they are known as the imported cabbageworm.
The butterfly life cycle consists of four stages: egg, caterpillar, pupa, and adult.
The cabbage white’s journey specifically begins when a female lays her eggs on the leaves of host plants, usually those from the cabbage family.
As the eggs hatch into caterpillars, they immediately start feeding on the leaves, eventually transforming into the adult butterflies we see fluttering around our gardens.
While the cabbage white butterfly itself is a delight to watch, it is essential to be aware of its association with the imported cabbageworm, a potential threat to the health of cabbage-family plants.
Understanding the life cycle of this butterfly can help in managing the impact of these pests in our gardens and farms.
Cabbage White Butterfly Life Cycle
Eggs
Cabbage White Butterflies lay single eggs on the leaves of host plants, typically plants in the cabbage family 1. The eggs are:
- Small
- Yellowish-white
- Often found on the underside of leaves
Larval Stage
Once hatched, the larvae, also called caterpillars, are green with a faint yellow stripe on the side 2.
They have several stages of development called instars.
- First instar: They are tiny with a length of about 2 mm
- Later instars: Caterpillars grow up to 1 inch
Larvae feed on host plants, sometimes causing significant damage to the leaves and crop.
Pupal Stage
Following the larval stage, the caterpillars transition into the pupal stage, also known as the chrysalis. Some key facts about pupal stage:
- Pupa can be green or brown to blend with the environment
- Typically attached to the host plant by silk threads
- Overwintering may occur in this stage for some individuals
Adult Stage
After the pupa fully develops, the adult cabbage white butterfly 3 emerges. Characteristics of adult stage:
- Medium-sized (2″ wingspan) white butterflies
- Black wingtips and spots on the wings
- Strong fliers with an affinity for nectaring
Identification and Physical Characteristics
Wingspan
The cabbage white butterfly is a medium-sized butterfly with a wingspan of around 2 inches 1. This makes it easy to spot in gardens and fields.
Male Vs Female
Cabbage white butterflies exhibit sexual dimorphism, meaning that males and females can be distinguished from each other by their physical features:
- Males: Have one black spot in the center of each forewing2.
- Females: Have two black spots on each forewing2.
Coloration
These butterflies are primarily creamy white in color, with some variations between males and females. Additional features include:
Habitat and Distribution
Geographical Range
The Cabbage White Butterfly, or Pieris rapae, belongs to the family Pieridae. It originated in Europe, but has now spread to other parts of the world, including:
- North America
- Asia
- North Africa
- Australia
- New Zealand
As an invasive species, it’s found in many regions across the United States.
Preferred Habitats
Cabbage White butterflies are adaptable. They can thrive in various environments. They are commonly found in:
- Urban areas
- Woodlands
- Heath
- Agricultural fields
These butterflies prefer habitats where they can lay their eggs on plants in the cabbage family, such as broccoli, cauliflower, and other Brassica plants1.
Habitat preferences:
- Wide range of plant hosts
- Accessibility to nectar sources
- Availability of suitable plants for egg-laying
Host Plants and Feeding Habits
Cabbage Family Plants
Cabbage white butterfly (Pieris rapae) is well-known for its association with plants in the cabbage family (Brassicaceae).
The larvae, known as the imported cabbageworm, feed on various cabbage family plants like:
- Cabbage
- Broccoli
- Cauliflower
These host plants provide nourishment to the caterpillars, helping them grow and develop.
However, these butterflies are such voracious eaters and easy breeders that they are considered major pests for these crops.
Other Host Plants
Apart from cabbage family plants, the cabbage white butterfly can also feed on other host plants such as:
- Horseradish
- Radishes
- Turnip
- Swede
- Nasturtiums
These plants attract cabbage white butterflies, providing them with essential nutrients for their existence.
By understanding the host plant preferences of the cabbage white butterfly, it becomes easier to manage and control their population, ensuring a healthy and thriving garden.
Economic Impact on Agriculture
Agricultural Pest
The cabbage white butterfly is a significant agricultural pest in its larval stage, affecting various crops, primarily those in the cabbage crop family.
The caterpillar feeds on the leaves and other parts of the host plant.
Their life cycle can take as little as 15 to 20 days in high temperatures, with the possibility of over 10 generations per year, making them a persistent threat.
The damage to crops can be substantial, rendering them unmarketable. Some examples of affected crops include:
- Cabbage
- Broccoli
- Cauliflower
- Brussels sprouts
The feeding damage by the caterpillars can lead to:
- Holes in the leaves
- Reduced crop yield
- Contamination by their presence
Biological Control Methods
Various biological control methods can help manage the population of cabbage white butterflies, reducing their impact on agriculture:
- Natural Enemies: Some wasp species, such as Cotesia glomerata, are parasitoids that lay their eggs in the cabbage white caterpillars, eventually killing them.
- Bacillus thuringiensis (Bt): This naturally occurring soil bacterium produces a toxin that is lethal to caterpillars when ingested. Bt is considered environmentally friendly and specific to caterpillars; it does not harm beneficial insects, humans, or other animals.
| Control Method | Pros | Cons |
|---|---|---|
| Natural Enemies | Target-specific, reduces pesticide reliance | Can be affected by climate change |
| Bacillus thuringiensis | Environmentally friendly, specific to caterpillars | Effectiveness depends on proper application |
By adopting these biological control methods, farmers can mitigate the economic loss caused by the cabbage white butterfly and maintain healthy crop yields while reducing the use of harmful chemical pesticides.
Conclusion
The Cabbage White Butterfly, a frequent visitor to gardens and farms, embarks on a captivating life journey from egg to fluttering adult.
While their elegant flight and distinct markings are a delight to observe, their larval stage, known as the imported cabbageworm, poses challenges for agriculturalists.
By understanding their life cycle, habitat preferences, and feeding habits, we can better appreciate their role in nature and implement effective strategies to manage their impact on our beloved cabbage-family plants.
Footnotes
