I've been using nematodes for 4 years now and they really work. Far less damage than before.
I was a sceptical at first .... thought it would be a bit of a gimmick ... but I'm really pleased with the result.
They are not cheap, but if they save a few plants then I figure they've paid for themselves.
I buy from a company called Gardening Naturally ... no charge for posting
I also get to spend more time actually gardening rather than just rounding the blighters up for hours on end!!