Selection for Fenpropathrin and FenpropathrinAcephate Resistance in the Silverleaf Whitefly (Homoptera: Aleyrodidae)

Abstract

A large, genetically diverse pool of Bemisia argentifolii Bellows & Perring was collected in 1994 from different crops, and a mixed colony was established in the laboratory. Subsets of this colony were reared on cotton plants held in large Plexiglas cages, and adult whiteflies were selected for resistance to fenpropathrin and to fenpropathrin + acephate (1:5). Selection was performed by exposing adults to treated glass vials at doses sufficient to give 60-80% mortality. Thirteen generations of adult selection with fenpropathrin + acephate yielded 856.3- and 1,289.3-fold tolerance (using lethal concentration ratio), respectively, to fenpropathrin and to fenpropathrin + acephate, indicating additive genetic variation for resistance in the source population. Selection with fenpropathrin alone yielded only a 10.9-fold increase in tolerance to fenpropathrin at the end of the selection period. There was no significant change in tolerance to fenpropathrin + acephate in this strain. Contrary to expectations, the early onset and the magnitude of resistance attained on selection with fenpropathrin + acephate compared with fenpropathrin alone indicates that this mixture evidently possesses a high degree of selectivity for development of resistance in B. argentifolii. Estimates of realized heritability of resistance to fenpropathrin and to fenpropathrin + acephate in B. argentifolii (in the fenpropathrin + acephate-selected strain) showed that they were significantly higher in the first half of selection (six generations), in both instances. Rearing of the fenpropathrin + acephate-resistant strain under conditions free of insecticides for six generations did not result in any significant decline in resistance, indicating that resistance is fairly stable.

Susceptibility of immature and adult stages of Trialeurodes vaporariorum (Hom., Aleyrodidae) to selected insecticides

“…Recently, another chloronicotinyl insecticide, acetamiprid, with mode of action similar to that of imidacloprid, has been registered for controlling whiteflies ( Horowitz et al., 1998). The pyrethroid, fenpropathrin, has been used against T. vaporariorum and other whitefly species in Asia and Europe ( Castresana et al., 1983; Natskova , 1985; Zhu et al., 1998), whereas it is normally mixed with acephate for controlling B. argentifolii or B. tabaci in the US ( Sivasupramaniam and Watson , 2000).…”

Characterization of Antixenosis in Soybean Genotypes to Bemisia tabaci (Hemiptera: Aleyrodidae) Biotype B

“…The management of this species is mainly done through the application of synthetic insecticides, which causes environmental imbalances, incurs production costs (Toscano et al 2001, Vieira et al 2013, and accelerates the insecticide resistance selection (Prabhaker et al 1998, Sivasupramaniam andWatson 2000). Because of these factors, it is extremely necessary to evaluate more sustainable control alternatives, and also alignment with the integrated pest management (IPM), reducing the abusive use of insecticides.…”

Diagnosis and characterization of insecticide‐insensitive acetylcholinesterase in three populations of the sweetpotato whitefly Bemisia tabaci

“…In contrast, selection with only fenpropathrin showed only slight (5fold) resistance over the same period to the mixture and no resistance to fenpropathrin alone. 13 In view of the fact that the insecticidal efficacy of acephate alone is very low in most US SPW populations, there are two possible alternative explanations for these observations : either there is a lack of intrinsic sensitivity of whiteÑy AChE to methamidophos (the bioactivated form of acephate) or there is widespread target-site resistance to this compound. Our in-vitro biochemical assays using methamidophos as an AChE inhibitor in the whiteÑy, described here, conÐrm the high level of insensitivity of the whiteÑy enzyme to this organophosphorus compound (Fig.…”