How to use Bayer Systemic on my orchids?

[susiep]

I was wondering if those of you with experience using the Bayer Systemic on orchids could give me some advice on how to use it. I am growing outside and at the mercy of nature. That means very hot and rains every afternoon (hard rain). I have resisted using systemic treatment on my orchids, although I use it on my shrubbery for the same bugs (scale, mealies). It works quite well, however it can cause leaf yellowing and loss on hibiscus. I didn't want that to happen to my 'chids! I have too many plants now to control the pests by hand and I want to stop using so much Orthene. Any advice would be appreciated and please suggest a regimen for use, too.