Trichogramma wasps for cabbage worms
UMass reports that T. brassicae, which is not native to New England, parasitises all the major brassica caterpillars and is sold on cards of parasitised eggs, about 100,000 wasps for up to an acre, at around $20–23 a card in 2022. Some growers release weekly for about four weeks and others through the life of the crop. UMass notes the developing wasps are protected from sprays while they are inside host eggs. Field efficacy data specific to imported cabbageworm were not found.
Before you order
Released weekly from cards while moths are flying and laying; the wasps kill the eggs before a caterpillar hatches. How it works, how to tell it has established and the supplier list are on the full Trichogramma spp. profile.
How many do I need?
Area and infestation level in; quantity, cost and a weekly schedule out. Open the calculator →
Other controls for cabbage worms
- Bacillus thuringiensis kurstakiMicrobial insecticide · Label rate — Thuricide 1–3 tsp per gallon for imported cabbageworm on broccoli, Brussels sprouts, cabbage, cauliflower, collards and kale; DiPel DF 0.5–2 lb per acre
- Braconid waspsWild parasitoid · Nothing to release — leave parasitised caterpillars and cocoon clusters on the plant
- Tachinid fliesWild parasitoid · wild, attract it
- Paper waspsWild predator (stings) · Wild — tolerate nests away from doors and paths