Question
Does anyone have any experience controlling scale with Bayer Tree and Shrub
care (imdocloprid)  using a self-watering pot (i.e.  - CWI or Natural Spring) ?
Is the dilution rate the same as a top watering system ?

Answer
I have no experience but have an opinion and some observations for your consideration.  First of all, the product is extremely safe to plants and I have never observed any phytotoxicity from imidacloprid.  As long as there is soil in the pot and the self watering system delivers water at prescribed times or by some other means, I would say mix at the recommended dilution rate.  It is just being delivered over a period of time instead of all at once.  The only problem is the product may be destabilized by the pH of your water.  Most insecticides are formulated as acids and if your city water is alkaline, which most are, it will deactivate the product in a day or so.  It may be better to drench the plant with a one time shot and do not let the watering system operate for a day or two, if possible.  The only problem I can speculate on is that if the plant is in a truly recirculating hydroponic situation, then the plant would be exposed to too much product with no buffering capacity from the soil.  In other words, I would go ahead and treat the plant according to the label instructions as far as dilution rates are concerned.  If you dont the scale will eventually cause great harm or even kill the plant.  I hope this helps you in making a treatment decision.  Good Luck.