Soft scale parasitoid wasps for brown soft scale
UC says a complex of Metaphycus wasps attacks brown soft scale, the commonest in Southern California being M. angustifrons rather than M. helvolus. Look for scales that are puffy or darkened, or that have a round exit hole. UC stresses that controlling ants is critical here, because they farm the honeydew and organophosphate and carbamate insecticides are not very effective against this scale. Avoid broad-spectrum sprays, and do not spray a population that is already heavily parasitised.
Before you act
Tiny wasps that lay in young soft scales and kill more by feeding on them. M. helvolus is the black scale parasite of Southern California citrus, and other Metaphycus species do most of the work on brown soft scale. Little is on sale, so conserve them. How to recognise it, what it is confused with and how to keep it around are on the full Soft scale parasitoid wasps profile.
Other controls for brown soft scale
- Rhyzobius lophanthaePredatory lady beetle · 2–5 per infested plant, or 2–6 per 10 ft² (1 m²), every 1–2 weeks