What can I do about woolly aphids on my apple tree?
Caryl Taylor, Norfolk
AANNE SAYS Colonies of brown aphids protected by white woolly coatings suck sap and cause stem swellings, offering entry points for canker. The natural army of aphid feeders (including earwigs) don’t make much of a dent in their population, so try scrubbing at small infestations or, if desperate, resort to an organic plant-oil spray.
On small trees, scrub off woolly aphids using a stiff brush