TY - JOUR AU - Castle, Steve AU - Henneberry, Tom AU - Toscano, Nick AU - Prabhaker, Nilima AU - Birdsall, Steve AU - Weddle, Dick TI - Silverleaf whiteflies show no increase in insecticide resistance JF - California Agriculture JO - Calif Agr Y1 - 1996/01/01 VL - 50 IS - 1 SP - 18 EP - 23 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://dx.doi.org/10.3733/ca.v050n01p18 L3 - 10.3733/ca.v050n01p18 AB - The silverleaf whitefly (Bemisia argentifolii Bellows & Perring) continues to be a difficult pest to control in California's desert valleys. To gain a better understanding of the possible role that insecticide resistance plays in its annual outbreaks, a resistance monitoring program was established to document susceptibilities of whiteflies to various insecticides through time. Continuous monitoring during 1993 and 1994 detected no trend toward higher resistance levels. Higher toxicities of insecticide mixtures compared to single insecticides were regularly observed in bioassay results. Various factors including diverse insecticide use and altered cropping patterns may have helped to avoid serious insecticide resistance problems in the Imperial Valley so far.