Confocal laser scanning micrograph of immunofluorescence-labeled corn stunt spiroplasma (CSS, Spiroplasma kunkelii, Class Mollicutes) aggregates (green) in whole mount preparations of its leafhopper vector D. maidis, showing the Malpighian tubule. Whole-mount organs were labeled with primary CSS antibodies then with secondary antibodies (Alexa Fluor-488, green), and stained with the nuclear stain propidium iodide (red). CIL:19120, from the same image group, is a labeled version of this image. 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. For additional information refer to Ammar and Hougenhout(2005) Ann. Entomol. Soc. Am. 98(6): 820Ð826.