MORPHOLOGICAL VARIATION IN BEMISIA ENDOSYMBIONTS

The ultrastructure of the endosymbionts of several populations of whit efly (Homoptera: Aleyrodidae) was examined using transmission electron microscopy. Consistent differences in morphology and relative number of endosymbionts were observed between species and biotypes of whitefl y within the Bemisia taxon. Bemisia argentifolii (=B. tabaci B biotype ) individuals from Hawaii, Florida, and Arizona contained two morpholo gical types of microorganisms housed within the mycetocyte cells of im mature whiteflies. Ln contrast, individuals from populations of B. tab aci A biotype from Arizona and Mexico, and B. tabaci Jatropha biotype from Puerto Rico, consistently contained three distinct morphological types of microorganisms within their mycetocytes. Organisms from B. ta baci A and Jatropha biotypes differed from each other in the relative frequency of each type of microorganism. These observations suggest th at different whitefly biotypes may have variable combinations of micro -fauna, with some possibly unique to each group, and furthers the hypo thesis that variation in whitefly endosymbionts may be associated with the development of biotypes.