Invertebrate diagnostician Joe Ostoja-Starzewski said: "I think it's rather draconian to say that as soon as you find (fucshia gall mite) you need to destroy all your plants - there's a fuchsia industry out there that needs to produce and sell plants."
Contrary to the RHS advice telling gardeners to dig up, burn or bury any infected plants, Ostoja-Starzewski said fuchsia gall mite can be treated with pruning and pesticides.
He said: "I'd say that if you have large numbers of fuchsia or fuchsia in hedging then controlling fuchsia gall mite is going to be quite difficult. But with small amounts of fuchsia in pots, conservatories and greenhouses, I don't see why you can't stay on top of the problem.Throwing the plants away willy-nilly is not really necessary when you can get on top of it by pruning and using chemical treatments."
RHS chief horticultural adviser Guy Barter responded: "It is true that cutting back and treating regrowth with the only insecticide available to gardeners - Westland Plant Rescue Bug Killer Ornamental Plants - and/or frequent treatment with materials with a physical mode of action such as oil-based insecticides might be effective.
"But the effort, cost and likelihood of disappointing results after doing this lead us, at the moment, to advise replacement for the average amateur gardener."
He added: "Fuchsia enthusiasts might, of course, be more motivated to attempt such control methods to preserve precious collections and we will examine their findings with great interest.
"But research on the situation in other countries leads us to believe the difficulties are great. If or when we find hot spots of infestation, we might review this advice."