Journal of Economic Entomology (1996) 89, 805-815

Nilima Prabhaker, N.C. Toscano, T.J. Henneberry, S.J. Castle and D. Weddle (1996)
Assessment of two bioassay techniques for resistance monitoring of silverleaf whitefly (Homoptera: Aleyrodidae) in California
Journal of Economic Entomology 89 (4), 805-815
Abstract: The relative toxicities of bifenthrin and endosulfan to silverleaf whiteflies, Bemisia argentifolii Bellows and Perring, were compared by 2 methods-treated glass vials and insecticide-coated yellow sticky cards-in tests in 4 field populations from cotton in Imperial Valley, California. Both techniques detected relative susceptibilities of B. argentifolii adults to bifenthrin and endosulfan. The LC₅₀s of bifenthrin ranged from 0.007 to 0.07 µg/vial for the 4 populations with the vial technique and from 0.77 to 3.55 µg(AI)/ml with the yellow sticky card technique. Relative tolerance levels to bifenthrin ranging from 2.2- to 10.1-fold were observed in the 4 populations with the yellow sticky card technique. The vial technique showed lower relative response levels (0.2- to 2.3-fold). With endosulfan, the range was similar for both techniques, (1.2- to 5.1-fold with vials; 0.5- to 7.0-fold with the yellow sticky card technique). The frequency of resistance to 4 insecticides compared with a greenhouse susceptible strain was evaluated with the vial system against 11 populations of silverleaf whiteflies collected from various crops in Imperial Valley during 1992. Resistance to endosulfan was substantial (maximum, 48-fold), but relative tolerance was considerably lower to bifenthrin (RR = 0.4- to 8-fold). The insecticide-coated yellow sticky card technique was used for monitoring in Imperial, Palo Verde, and San Joaquin Valleys in California in the following year. Considerable differences in resistance ratios for the 4 insecticide treatments were observed among whitefly populations from the 3 geographic regions. Bioassays indicated that methomyl was effective against adults in all locations.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Bemisia tabaci biotype B	Cotton (Gossypium)	U.S.A. (SW)