A pic would help you get suggestions about the spots. You can't spray for or against anything unless you know if and what you have, or are expecting something in particular.

We don't spray Camellias with anything but they do need to be trimmed because someone put them too close to the house 30 years ago. If shrubs fit where you put them, they don't need to be pruned, except very lightly and occasionally, to maintain form and overall shaping, or if you just like a formal, manicured look. Camellias are able to perform both ways and still bloom well.