Recently, the Home and Garden Information Center (HGIC) has been receiving photos of coneflowers (Echinacea purpurea) that are malformed and green. The plants are infected with aster yellows, a bacterial phytoplasma (a type of bacterium that does not have cell walls). Aster leafhoppers (Macrosteles quadrillineatus) carry the pathogen and infect the plant tissue when they feed on it. They are small olive-green to tan insects with wedge-shaped bodies. Adults are 1/8 in length and have three pairs of spots on their heads.