Pests & diseases › Cabbage White Butterfly
Cabbage White Butterfly
Large and small white butterflies whose green and yellow caterpillars strip brassica leaves to ribbons.
Symptoms
- Clusters of yellow eggs on leaf undersides
- Velvety green caterpillars (small white) or yellow and black caterpillars (large white)
- Leaves chewed to skeleton stems in days
- Frass (droppings) wedged in cabbage hearts
Lifecycle
Two main generations: May to June, then August to September.
What to do
- Inspect leaf undersides twice a week — squash egg clusters
- Pick caterpillars off by hand into a bucket of soapy water
- Spray heavy infestations with Bacillus thuringiensis (Bt) — caterpillar-specific bio-control
- Encourage parasitic wasps by growing flat-flowered umbellifers (dill, fennel)
If it's bad
- Pyrethrum spray for serious attacks
Stop it coming back
- Insect-proof mesh over brassicas from May onwards
- Decoy white butterflies — old eggshells on canes have been shown to deter (they think the patch is taken)
Crops it goes for
Broccoli
Brussels Sprouts
Cabbage (Red)
Cabbage (Spring)
Cabbage (Winter)
Calabrese
Cauliflower
Kale
Kohlrabi
Pak Choi
Plan the plot, track every sowing, cook the harvest
Sowing reminders and harvest forecasts for your own frost dates, the Seed Tin, Scan Centre for any label or packet, and the Potty Mouth Garden Club. Free to start.