Cheers guys. Yes I know about the controversy surrounding Imidacloprid/Confidor, hibiscus isn't flowering at the moment and probably wont until the mealy bugs are under control, it's that bad...
Interesting that it's a nicotine based insecticide! The things you learn!
The actual product I'm using is Spectrum 200SC (
https://specialistsales.com.au/imida...icide-1-l.html)
Might have to look for more information about stem injection - though I can't see why it wouldn't work on large enough plants?
Until APVMA decide that all the alleged risks hold true in Australia I'll keep using it. Interestingly it is specifically mentioned to be soft on non-target insects such as ladybirds, hoverflies, spiders and predatory mites.