VIEW ARTICLE

Vector Relations

Colonization of the Sharpshooter Vectors, Oncometopia nigricans and Homalodisca coagulata, by Xylem-Limited Bacteria. R. H. Brlansky, Assistant professor, University of Florida, Institute of Food and Agricultural Science (IFAS), Agricultural Research and Education Center, Lake Alfred 33850; L. W. Timmer(2), W. J. French(3), and R. E. McCoy(4). (2)Associate professor, University of Florida, Institute of Food and Agricultural Science (IFAS), Agricultural Research and Education Center, Lake Alfred 33850; (3)Professor, University of Florida, IFAS, Agricultural Research Center, Monticello 32344; (4)Professor, University of Florida, IFAS, Agricultural Research and Education Center, Ft. Lauderdale 33314. Phytopathology 73:530-535. Accepted for publication 12 October 1982. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-530.

Xylem-limited bacteria (often referred to as rickettsialike bacteria) were observed in the cibarium, the apodemal groove of the diaphragm, and the precibarium of the sharpshooters, Oncometopia nigricans and Homalodisca coagulata, by scanning electron microscopy. Bacteria colonized the cibarium, precibarium, and the apodemal groove of the diaphragm of O. nigricans after the insects had fed on Pierce's disease-affected grapes or periwinkle wilt-affected Catharanthus roseus. In H. coagulata, which were collected from orchards with phony peach disease or fed on plum leaf scald-affected plants, bacteria were attached to the floor of the cibarium, the apodemal groove of the diaphragm, and the walls of the precibarial area above and below the valve. Bacteria in both sharpshooter species were attached by one end to the walls of the cibarium and precibarium by means of extracellular material and possibly fimbraelike structures. Some dividing bacteria were observed.