CHARACTERIZATION AND DISTRIBUTION OF ESTERASE ELECTROMORPHS IN THE WHITEFLY, BEMISIA-TABACI (GENN) (HOMOPTERA, ALEYRODIDAE)

Esterase profiles were examined for over 40 populations of the whitefly Bemisia tabaci, obtained fr om native and cultivated plant hosts worldwide. Twelve unique electromorphs were identified from distinct populations concentrated largely in Central America, Africa, and India. One electromorph, type B, has recently been proposed as a separate species, Bemisia argentifolii, and has recently spread throughout much of the world. When considered with evidence from mating studies and the ability to induce phytotoxic disorders (squash silverleaf disorder), our data suggest that the single taxon Bemisia tabaci may actually represent a species complex.