Cabbage Loopers Pests in the Vegetable Garden
Often confused for cabbage worms simply by name and appearance, loopers and worms are strikingly different from one another once you understand the signs.
Loopers of any kind are easily recognizable by their uniquely bent, almost cartoon-like, gait as a result of having too few abdominal prolegs. Rather than walking smooth and grounded like a caterpillar or centipede, the cabbage looper performs a tall "looping" curve to compensate for no abdominal support.
Don’t let the name fool you because cabbage loopers have a much broader appetite than just cabbage, kale, and other Brassicas. Cabbage loopers earn the name because of the habits of more matured loopers that tunnel their way through the heads of perfectly harvestable cabbage, the same way worms may tunnel out apples and stone fruit.
Facts About Cabbage Looper Garden Pests
- Cabbage Looper Distribution: Native throughout North America in greenhouses and warmer winter climates
- Cabbage Looper Host Plants: Nearly any fruit, vegetable or ornamental greenhouse crop, with the most damage done to crucifers
- Cabbage Looper Lifespan: ~4 weeks as larval looper (~10-14 days as adult moth)
- Cabbage Looper Eggs Laid per Lifetime: ~250-350
- Cabbage Looper Removal: Predatory insects, neem oil, castile soap, BT spray (Bacillus Thuringiensis), pyrethrin spray, spinosad
- Cabbage Looper Predators: Parastic wasps, lacewings, ladybugs, spiders, grasshoppers, birds
- Most Common Looper in North America: Cabbage Looper (Epilachna varivestis)
What Do Cabbage Loopers Look Like?
Cabbage loopers are merely the 3-4 cm long soft-bodied larvae of much larger adult moths.
Unlike regular caterpillars which have strong abdominal legs, loopers of all types do not have any which cause their bodies to perform a characteristic upright bend while walking, as opposed to a smooth grounded motion like caterpillars, centipedes, or slugs. Cabbage loopers are green and share similar markings to cabbage worms and hornworms, but are noticeably smaller and lacking the additional prolegs.
Alfalfa, soy, and cabbage loopers can be hard to differentiate from one another because they share very similar size and color, aside from their choice of host plant. Loopers are generally easy to identify simply by their unique way of walking caused by the missing abdominal prolegs.
Cabbage Looper Damage to Garden Vegetables
Young and developing larvae from moths and butterflies are notorious for being ravenous leaf eaters all the way until adult maturity.
Similar to any hornworm or caterpillar, cabbage loopers are large enough to chew directly on a host plant as soon as they hatch, primarily feeding on the bottom half of the foliage during the first three instars. While the youngest larvae feed on plants whole from root, stem, to leaf, it is the more developed cabbage loopers that give the insect its name by burrowing and tunneling into full grown heads of cabbage.
Loopers do not swarm like other pests but, similar to hornworms and grasshoppers, just one unchecked cabbage looper in the garden is still plenty to cause sharp defoliation and crop loss.
What Do Cabbage Loopers Eat in the Garden?
Don’t let the name fool you because cabbage loopers have a much broader appetite than just cabbage, kale, and other cruciferous vegetables. Like many types of larvae, cabbage loopers are ravenous and not choosy of the host they inhabit. Cabbage loopers have been found to feed on almost anything in the greenhouse and garden bed including pea, tomato, lettuce, spinach, and countless ornamental flowers.
Cabbage loopers earn the name because of the habits of much larger and developed loopers which tunnel their way through the heads of perfectly harvestable cabbage, the same way worms may tunnel through apples and stone fruit. Try planting nasturtium as a companion or trap crop to keep loopers fed on its spicy blooms and greens rather than your cabbage harvest.
Cabbage Looper Eggs
Adult moths of fully matured cabbage loopers do not lay dense clusters of eggs, but merely lay 1-7 solitary eggs at a time on the underside of host leaves. Larger moths and butterflies do not lay eggs as frantically as much smaller pests because moths can fly great distances to lay an average of 250-350 over the course of their lives.
Cabbage looper eggs are pearlescent white, translucent, and perfectly sphered as opposed to more oblong chicken eggs. Because cabbage looper eggs are not clustered, the individual eggs have a bit of a sticky surface to keep them affixed.
Finding eggs in the brief 4-10 day window until hatching is one of the most effective ways to prevent any damage and crop loss from more mature cabbage loopers. Larvae will begin to feed on the host plant immediately.
How To Rid Cabbage Loopers from the Home Garden
Cabbage loopers are easier to remove from the garden because they are smaller, softer, and have more predators than larger beetles or hornworms.
Ladybugs, parasitic wasps, and lacewings are natural predators of cabbage loopers whose eggs can be commercially bought from nearly any nursery or garden supply store.
Because cabbage loopers are merely soft-bodied larvae of much larger moths, DIY soap solutions and neem oil sprays are widely effective against many different types of loopers. Try an organic BT spray (Bacillus Thuringiensis), spinosad, or a pyrethrin-based insecticide if the problem persists.
Cabbage loopers are solitary insects that do not swarm, making it possible to simply remove eggs and troublesome loopers by hand. Diatomaceous earth has been known to remedy minor infestations.