Cabbage White Caterpillar – Identification and Control

Last updated October 1, 2023

Discover the world of the Cabbage White Caterpillar, a common yet notorious garden pest.

In this article, we dive into the crucial aspects of identifying these voracious larvae and implementing effective control strategies.

Arming yourself with insights into the Cabbage White Caterpillar’s lifecycle and behavior can make all the difference in safeguarding your precious plants.

Identification

Small Cabbage White Caterpillars and Butterflies

The small cabbage white butterfly is white in color, with two black dots on its wings.
The wingspan can reach up to 1.8 inches (4.5 cm).
They lay hundreds of eggs randomly on the leaves of host plants.
These eggs are hatched into velvety green caterpillars.
Usually, caterpillars are solitary. They will not feed in groups.
The average length of the caterpillar is about 1.2 inches (3 cm), but it can grow up to 1.6 inches (4 cm).

Large Cabbage White Caterpillars and Butterflies

The large cabbage white butterfly is white with a black band on the tip of its forewings.
The underside of wings is pale green.
Females have black spots on their wings.
The wingspan can reach up to 2.6 inches (6.5 cm).
It lays eggs in clusters of 20 on the underside of the leaves of the host plant.
These eggs hatch into black and yellow hairy caterpillars.
These caterpillars will feed in large groups.
The average length of the caterpillar is about 1 inch (2.5 cm), but they can grow up to 2 inches (5 cm).

Both small and large cabbage white butterflies look very similar, and to the untrained eye, you might even say they look the same. The main differences between the two species are the color of their caterpillars and the way the butterflies lay their eggs. However, identifying the two species is not really important for a home gardener, as the damage and control are similar. So, in this article, we will discuss both species as one and refer to them as cabbage whites.

Lifecycle

Cabbage white butterflies emerge in spring. They will fly around the garden feeding on pollen and nectar, mate, and lay multiple batches of yellow eggs. These eggs will hatch into caterpillars, which will go through numerous molting and instar stages. These caterpillars eat voraciously and cause a lot of damage to host plants. Caterpillars require an abundant amount of food for full development, or they will die before becoming a butterfly.

After the final instar, the caterpillar pupates. Pupae color usually matches the background of where it is attached to. For example, if the pupa is attached to the green plant, it will be greenish. If the pupa is attached to the brown fence, it will be brownish. After butterflies hatch, they will start feeding and mating straight away. This will last until the end of autumn. Then the last generation of the year will enter the pupa stage and pupate throughout the winter.

The lifespan of an adult butterfly is up to 3 weeks. There can be up to 3 generations per year.

Damage They Cause

These caterpillars are common pests that can cause significant damage to their host plants by overeating foliage. The larger holes in the leaves of the host plant will indicate the presence of these caterpillars. These pests make tunnels through the hearts of cabbage and contaminate it with their excrement. But it is easy to spot them. Just look for droppings on the leaves. If you see the droppings, that means the caterpillars are on the leaves above.

Adult butterflies will not cause damage, but they will lay many eggs that can decimate your brassica crops.

Plants They Attack

These pests will attach all types of brassica plants like cabbages, swede, turnips, cauliflower, brussels sprouts.

Gooseberry bush, nasturtiums, and rapeseeds also get attacked by these pests.

Live Biological Control

Cabbage white caterpillars are particularly vulnerable to a Parasitic Ichneumon wasp.

The Tachinid Flies and Spiked Shieldbug are very efficient beneficial insects in controlling cabbage white caterpillars.

Predator insects such as Assassin Bugs, Damsel Bugs, Green Lacewings, Hoverflies, Spiders will destroy eggs or attack very young caterpillars.

Birds, bats, frogs, toads, lizards, hedgehogs, and shrews will also eat cabbage white caterpillars.

Organic Control

You can use garlic spray, citrus, and botanical oils against cabbage white caterpillars.

Preventive actions

Inspect your brassica plants regularly.
Collect the caterpillars and dispose of them into the bucket of soapy water.
Squash egg clusters by hand.
Protect your plants with horticultural fleece or fine netting to keep butterflies from laying eggs.
Attract predator birds by hanging bird feeders and nests close to your garden.
Grow sacrificial plants such as nasturtiums to trap the caterpillars.
Plant varieties that are less vulnerable to cabbage white caterpillar attacks.
Sprinkle host plant with cornmeal or rye flour. If cabbage white caterpillar eats it, it will bloat and die.

Did you know?

If you see a white butterfly flying around your garden, most likely it is the cabbage white butterfly. Very rearly you will see any other white butterflies in a fruit and vegitable garden.

Cabbage white butterflies are very strong flyers. Adult butterflies are known to fly up to 12 km in one flight, but this is rarely done. Normally, females will fly around 0.7 km per day, and males will fly around the host plants, waiting for females.

Cabbage white caterpillars are considered a serious pest. However, cabbage white butterflies are excellent pollinators.

Cabbage white butterflies are poisonous to most garden birds. This is due to the accumulation of oils in their bodies from mustard, oil-seed rape, sprouts, and cabbages they have eaten during their larvae stage.