white rings
 

One more thing I have noticed on my pepper plants which are so heavily
infested with leaf miners: now and then I find, on the underside of
leaves, white rings. It is not just a single ring. There will be one
large ring and then within it many smaller rings. And the whiteness
appears kind of powdery. Are these the marks of whiteflies? Nothing I
have read about whiteflies so far specifies that they leave this
particular pattern of rings. And if the best thing to do here to
remove leaves that have the rings, as one does when one sees evidence
of leaf miners? If anyone could shed some light on the subject, I'd
appreciate it. Thanks.