Resistance Plutella xylostella

Insects have evolved resistance to Bt toxins in the laboratory, yet only one crop pest, the diamondback moth (Plutella xylostella), has evolved resistance to Bt toxins under open field conditions (Tabashnik et al. 2003). But this resistance was not caused by Bt crops, rather it occurred in response to repeated foliar sprays of Bt toxins to control this pest on conventional (non-GE) vegetable crops (Tabashnik 1994). Based partly on the experience with diamondback moth and because Bt crops cause season-long exposure of target insects to Bt toxins, some scientists predicted that pest resistance to Bt crops would occur in a few years. 

Yu, S. and McCord, E., Jr., Lack of cross-resistance to indoxacarb in insecticide-resistant Spodoptera frugiperda (Lepidoptera Noctuidae) and Plutella xylostella (Lepidoptera Yponomeutidae), Pest Manag. Sci., 63, 63, 2007. 

Ismail, F. and Wright, D.J. (1991) Cross-resistance between acylurea insect growth regulators in a strain of Plutella xylostella L. (Lepidoptera Yponomeutidae) from Malaysia. Pesticide Science 33, 359-370. 

While dieldrin target-site resistance (Section 29.5.2.2) can confer some level of resistance to fipronil, this cross-resistance has not led to failure of fipronil in the field. However, resistance due to other mechanisms was seen in southeast Asia as early as 1996 in diamondback moth Plutella xylostella), within three years of the introduction of the product. The high intrinsic activity of fipronil and lack of alternatives in the mid-1990s led growers in countries such as Thailand to use it up to 40 times per year on cruciferous crops. By early 1997, many populations were resistant and field failures were widespread. At the same time, use of the... 

Pyridalyl controls a wide variety of lepidopterous pest strains such as the diamondback moth (Plutella xylostella) which is resistant to various existing insecticides (8). This insecticide is also effective against thysanopterous pests. Moreover, it does not exert an adverse effect on various beneficial arthropods such as natural predator insects (e.g., Oristar-A ) and honeybees. Therefore, this novel insecticide is expected to be a usefiil material for controlling lepidopterous and thysanopterous pests in IPM and insecticide resistant management programs. 

Eigenbrode, S.D., K.E. Espelie A.M. Shelton. 1991. Behavior of neonate diamondback moth larvae [Plutella xylostella (L.)] on leaves and on extracted leaf waxes of resistant and susceptible cabbages. J. Chem. Ecol. 17 1691-1704. 

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