Answer: Without knowing why you want to spray it is difficult to make a specific recommendation. However, horticultural oil such as Sun Spray Ultra Fine Spray Oil or UltraFine Oil can be used to control lacebugs on azaleas, as can commercially formulated insecticidal soap. Read and carefully follow all of the label directions for use, including the followup reapplication schedule. Lacebug control is usually most effective when begun in the spring.
I would suggest you consult with your local Penn State cooperative extension to specifically identify the problem you want to treat, and based on knowing that, decide what to do. If a chemical control is needed, they will have the most up to date information on what to use and how/when is best to use it for maximum results.
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