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extremely small. red. herbivore.
Although this photo is too blurry for an ID, I can confidently tell you this is neither a spider mite (Tetranychidae) nor an herbivore. This is a parasitengone mite and is probably either a trombidiid (compare with these images: http://bugguide.net/node/view/2419/bgima...) or an erythraeid (compare with these images: http://bugguide.net/node/view/91156/bgpa...). Either way, it is a predator as an adult and a parasite as larvae... of other arthropods in both cases.
Is it magnified? It seems too large for a spider mite. They are hard to see without a hand lens.