Micrograph of a semi-thick (1-2 µm) section of an infected maize leaf, with silver-enhanced immunogold labeling, that shows dark staining of corn stunt spiroplasma (CSS, Spiroplasma kunkelii, Class Mollicutes) aggregates in phloem tissue. The section was counter stained with toluidine blue. CIL:19129, from the same image group, is a labeled version of this. CSS is a wall-less procaryote that causes corn stunt disease and is biologically transmitted by some leafhopper species, e.g. Dalbulus maidis and D. gelbus (Hemiptera, Cicadellidae). Spiroplasma cells are limited by a unit membrane with no cell wall. They can be quasi-spherical, pleiomorphic or maintain a filamentous/spiral form. CSS multiplies in both plant and insect hosts and is transmitted with salivary secretions during feeding of the vector on new host plants. dditional related images from this contributor are available in the Library.