Persistent silverleaf whitefly exploits desert crop systems

Abstract

When clouds of whiteflies swarmed through California's desert agricultural areas in the fall of 1991, they were initially identified as a new strain of the sweetpotato whitefly, Bemisia tabaci. The previously known strain was called “A” or “cotton,” while the new strain was called “B”, “Florida” or “poinsettia.” Since then, research has shown that this new pest is actually a distinct species, Bemisia argentifolii (Bellows & Perring), and is known as the silverleaf whitefly. Since its introduction in the United States, the silverleaf whitefly has cost more $2 billion in crop loss and damage, and pest control. The silverleaf whitefly is exceptional in its ability to colonize a great variety of crops, weeds and ornamentals. Southern California's diverse crops, high temperatures, and low rainfall help sustain whitefly populations at high levels, even during the winter months. The level of infestation of crops attained by silverleaf whitefly populations is driven by the insect's biological traits, the crops grown and the inadequacy of pest controls.