I moved my Hollyhocks to a part of my garden where they would get more water on a regular basis. They have so far done well and are bigger and fuller then they ever were. But, about two weeks ago I noticed something appeared to be nesting on the underside of the leaves. There were hundreds on each leave- about the size of a pinhead and rust in color. They do not appear to be any of the typical Hollyhock diseases. I cut off each infested leave and threw it in the garbage. The interesting part is I have tons of other perennials in the same area and none of them are affected- just my hollyhocks. There are other plants in between my hollyhocks and they are fine- whatever it is simply liked the hollyhocks. Any ideas? Thanks!