Thought I'd share this article from Dave's Garden.
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what used to be called "dormant spray/oil" is now formulated quite differently. Inter alia, it is no longer necessarily petroleum-based. Article says it can be used on Whitefly. NOW they tell me! I had such horrible struggles with Whitefly on my Hibiscus-- tried everything! -- that I finally got rid of it some years ago.
Hope article is of interest to others.
HB