Q Can you identify which insect is using the clump base of my phormium as a nursery?
Ronwen Reid, North Wales
A CHRISTINE SAYS What you are seeing is typical of the difficult-to-control pest mealybug. This is a small, hairy insect up to 7mm long, which is covered by white, waxy fibres that give it an almost waterproof covering. This makes the use of insecticides difficult, as wetting the mealybug becomes impossible.
Since good control using an insecticide is not often achieved, I would use a biological-control method on such a population. Obtain the ladybird Cryptolaemus montrouzieri from a biological insect supplier (found online) and follow the instructions to the letter. The ladybird needs high temperatures so tends only to be successful between May and September. If the plant is heavily infected, it may be better in the long term to dispose of it.