Ladybugs for cabbage aphid
UMass rates lady beetles effective against high cabbage aphid populations but highly dispersive: released beetles leave if aphids are scarce. They can work when released under row cover on winter greens in a tunnel. In the open, avoid broad-spectrum sprays and use Bt against caterpillars on the same crop.
Before you act
Everyone's first idea for aphids, and the one beneficial where buying is usually the wrong move. The ladybugs sold by the tub are convergent lady beetles collected from the wild, and UC IPM says most fly away within a day or two of release, even when aphids are plentiful. The larvae do much of the eating, and they turn up on their own wherever there are aphids. How to recognise it, what it is confused with and how to keep it around are on the full Ladybugs profile.
Other controls for cabbage aphid
- HoverfliesWild predator (larvae) · Wild — plant alyssum, dill, cilantro or Ammi majus near the brassicas
- Aphidoletes aphidimyzaPredatory midge · 1–10 /m² per release, weekly
- Chrysoperla carneaGreen lacewing larvae · 2–20 /m² per release, weekly
- Cabbage aphid parasitoidWild parasitoid wasp · Wild — grow Ammi majus and other flowers near the brassicas