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I have a lemon/mandarin cross citrus tree in my conservatory and I've just noticed it has a scale insect on it.  Any ideas how to get rid without resorting to chemicals?

Thanks :)

Haven't I heard that somewhere you rub em with meths on a cotton bud?

mad as this sounds,
when my grapevine was horribly infested i scraped them off with a knife every day for two weeks  :P .
after the first week they were really hard to find.
had no probs all the rest of last year though not very much fruit. won't know for sure til this summer i'm afraid.
Tara xx