On the Food & Environment Research Agency website, a fact sheet details control products that include abamectin, which is present (with thiamethoxam) in the Westland product Plant Rescue Bug Killer for Ornamental Plants.
Dove Associates advised the RHS that the control was available after RHS principal entomologist Andrew Halstead said, when launching the RHS 2011 top 10 most complained about garden pests: "Unfortunately there are no effective pesticides for garden use. Because the damage cannot be controlled, it may lead to a decline in the popularity of this valuable garden plant."
But RHS advisory service head Guy Barter said Halstead was mistaken: "There is strong evidence that abamectin would be effective. I think this was a misunderstanding. What we meant was in a wider sense there is not a lot of control for gardeners because it is not feasible to rely on one pesticide for ever."
Dove Associates added that the pest was not a problem for commercial growers.
Fuchsia gall mite was discovered in a garden in Hampshire in 2007 and has become established along the south coast. "This is a devastating, microscopic pest of fuchsias that will probably eventually spread throughout Britain," said Halstead.
Garden writer Peter Seabrook said: "I'm disappointed that the RHS doesn't indicate the plant protection materials available and why the options aren't given to gardeners and their members to decide for themselves."