Here are tips on how to identify, control, and get rid of imported cabbageworm.
What are Cabbageworms?
Cabbageworms are the same pest as “imported cabbageworms” and “cabbage worms.”
The adult butterflies are sometimes called cabbage whites or small whites. The Latin name is Pieris rapae, or Artogeia rapae.
This is a common pest for kale, cauliflower, broccoli. and other members of the cabbage vegetable family.
Do not be overly concerned if you see a hole in a leaf; plants can withstand much leaf loss without consequence.
It is during seedling establishment or early head formation that plants will incur true damage to their growth and yield.
How to Identify Cabbage Root Maggots
These pretty white butterflies (right picture) flying around your veggies are laying eggs which then hatch into small, fuzzy green worms (left picture) that chew the cabbage and deposit worm poop.
The eggs and larvae of the cabbage looper, diamondback moth, and zebra caterpillar also can be found hanging around.
How to get rid of Cabbage Root Maggots
Cover your plants with row covers to deter the adult butterflies from laying eggs on the cabbages.
Manually remove (handpick) the eggs if possible.
Yellow sticky traps will catch the adult butterflies, but may also catch beneficial insects.
Spraying with BTK (Bacillus thuringiensis var. kurstaki) every 1 to 2 weeks will also help control cabbage family pests. Sevin also is effective. And, the few pests that remain on the vegetables can be washed out after harvest using water and a small amount of detergent or other surfactant.
It is said that if you dampen cabbage leaves and sprinkle them with cornmeal, the caterpillars will eat the meal, swell, and die.
Trichogramma wasps (very tiny; they do not sting humans) parasitize the eggs of the imported cabbageworm; these beneficial insects are available by mailorder, although you'll need to time their release appropriately–the mailorder company would be able to help you.
Check with your local Cooperative Extension for your area's regulations on chemical control.