Cabbage Butterfly Control

Symptoms

Large velvety green caterpillars with faint yellow lines feed voraciously on the leaves, eating large irregular holes and often leaving only the midribs and veins. They feed openly and can defoliate plants quickly. Their wet greenish black droppings soil the leaves and heart of the plant, lowering quality.

Damage

The cabbage butterfly, whose caterpillar is the large cabbage white, is a major defoliator of cole crops especially in cooler hill and winter conditions. Heavy infestation can strip plants of leaves, stunt head formation and contaminate the produce with droppings, leading to significant yield and quality loss. Young plants are most vulnerable.

Organic & cultural control

Hand pick and destroy the large caterpillars and the yellow egg clusters laid on the underside of leaves, which is easy because they are large and visible. Spray Bacillus thuringiensis which kills the caterpillars while sparing natural enemies. Conserve parasitoids and predators, spray neem seed kernel extract, and keep the field clean of cruciferous weeds.

Chemical control

When caterpillars are numerous, a recommended insecticide such as spinosad, emamectin benzoate or a labelled product for cole caterpillars can be sprayed, preferably while larvae are young. As with diamondback moth, rotate insecticide groups and direct spray into the canopy with a wetting agent. Use only labelled products at the correct dose, follow the pre-harvest interval and consult your KVK or agronomist before spraying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Scout regularly for yellow egg clusters and young caterpillars and remove them by hand before they grow large. Use Bacillus thuringiensis as the main tool and conserve natural enemies. Avoid overlapping cole crops, remove crop residues after harvest, and rotate with non cruciferous crops to reduce carry over.