Cabbage white caterpillar infestations in a garden can cause serious damage to brassica crops such as cabbage, broccoli, cauliflower, and others. The caterpillar feeds on the leaves, stem and buds of the plant, causing holes and reducing the growth of the plant. An infestation can cause the plant to become stunted or even kill it, so it’s important to identify and treat the problem quickly.
Symptoms
- Significant damage to the leaves of the plant, with large holes being eaten through the leaves
- Wilting or yellowing of leaves, indicating stress to the plant
- Stunted growth of the plant and overall reduction in size
- Reduced production of edible parts such as heads of cabbage or broccoli
- Presence of numerous caterpillar droppings (frass) on the leaves and surrounding soil
- Evidence of webbing or silk on the leaves and around the base of the plant
- Presence of pupae or cocoons on the undersides of leaves or in nearby soil or plant debris
It is important to keep an eye out for these symptoms and take action promptly to prevent further damage to the garden.
What is a Cabbage White Caterpillar
- Pale green or yellowish body with black stripes running along the sides
- Approximately 1 inch in length, with a cylindrical shape
- Black head and legs, which are short and stubby in appearance
- Black dots or spots along the sides of the body
- A distinct white stripe runs down the center of the back
- Smooth and hairless body
Treating a Cabbage White Caterpillar Infestation
It may be necessary to use multiple methods to effectively control a cabbage white caterpillar infestation. For example, physical removal and chemical control may be used together to remove the current population and prevent new generations from establishing.
Physical Removal
- Hand picking and removing caterpillars and their eggs from the plants on a daily basis
- Destroying any pupae or cocoons found on the plants or nearby soil
- Regularly inspecting the plants for any signs of infestation and removing any new generations
- Using sticky tape or barriers, such as a physical barrier made of fine mesh, to prevent the caterpillars from accessing the plants
- Pruning and removing any heavily infested leaves or plants to reduce the population
Natural Predators
- Introducing natural predators such as birds, ladybugs, and lacewings to the garden
- Creating a habitat that attracts these predators to the garden, such as providing nesting boxes or a water source
- Avoiding the use of insecticides that may harm the natural predators
- Maintaining a diverse garden ecosystem to support a balanced population of predators and prey
Chemical Control
- Selecting an appropriate insecticide that is registered for use on the specific crop and caterpillar
- Following the label instructions carefully, including any precautions for personal safety and environmental protection
- Making sure to spray the undersides of the leaves where the caterpillars may be hiding
- Rotating the use of insecticides to prevent the development of insecticide resistance in the population
- Monitoring the plants regularly to ensure the treatment is effective and reapplying as needed
Cultural Control
- Planting brassica crops that mature at different times to reduce the risk of a mass infestation
- Implementing crop rotation to reduce the buildup of pests and diseases in the soil
- Maintaining proper garden sanitation, such as removing plant debris and weeds from the garden to reduce hiding places for pests
- Choosing brassica varieties that are resistant to the cabbage white caterpillar
- Covering the plants with floating row covers to exclude the caterpillars