Rudbeckia psyllid nymphs cause large, purple raised blotches on the foliage of Rudbeckia. Look on the underside of the leaves for the bright red and white insect that resembles a leafhopper. Nymphs feed by inserting their needle-like mouthparts into lower surfaces of the leaf and sucking out plant juices. This feeding causes a distinct, shallow depression on the lower leaf surface and purplish spots as seen in this photo. The veins may also turn purple over the lower leaf surface. It has been found in Ohio, NY, NJ and CT.