Description of a species of Bemisia (Homoptera: Aleyrodidae).
Bemisia argentifolii sp. nov. is described from material collected in California and Florida. This species has been referred to elsewhere as B. tabaci strain B or B. tabaci poinsettia strain. The species has been demonstrated to be distinct from B. tabaci by crossing experiments, studies on intraspecific and interspecific mating behaviour, analysis of allozymic frequencies, PCR analysis of genomic DNA and morphological evaluation. The description of the new species is based on morphological and allozymic characters. The species is distinguished from B. tabaci in the 4th nymphal instar by the absence of a dorsal seta, the width of the thoracic tracheal folds, the width of the wax extrusions from the tracheal folds, and, in the adult, by migration distances of allozymes for 3 enzyme systems.