Transgenic crop "pyramids" producing two or more Bacillus thuringiensis (Bt) toxins active against the same pest are used to delay evolution of resistance in insect pest populations. Laboratory and greenhouse experiments were performed with fall armyworm, Spodoptera frugiperda, to characterize resistance to Bt maize producing Cry1A.105 and Cry2Ab and test some assumptions of the "pyramid" resis...

In the mid 1980’s, management of Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), in brassica vegetable crops was at crisis level with spray failures prevalent across the industry in Southern Queensland. Insecticide resistance to synthetic pyrethroids was identified in 1986, and resistance monitoring between 1988 and 1992 showed that problems also existed with carbamates, ...

Development of insecticide resistance has been a serious concern worldwide, whose mechanisms have been attributed to evolutionary changes in pest insect genomes such as alteration of drug target sites, up-regulation of degrading enzymes, and enhancement of drug excretion. Here, we report a previously unknown mechanism of insecticide resistance: Infection with an insecticide-degrading bacterial ...

Large scale application of chemical pesticides to reduce the crop losses caused by insect pests and diseases, valued at over US$250 billion annually, has not only led to serious environmental hazards, but has also resulted in development of resistance to pesticides in pest populations. It is in this context that crop varieties capable of resisting pest damage will play a vital role in reducing ...

The cabbage seed weevil, Ceutorchynhus assimilis (Paykull) (Coleoptera: Curculionidae) is a pest that more and more often causes large financial losses for rapeseed cultivators in Poland and other European countries. One of the reasons of these problems is the resistance of the pest to certain active substances of insecticides. The aim of the study was to assess the susceptibility level of the ...

The Plutella xylostella (L.) (Lepidoptera: Plutellidae) is a worldwide pest of Brassicaceae. Resistance has evolved against various insecticides including chlorfenapyr one of the most recently registered molecules to control this pest. The failure of chlorfenapyr to control this pest could be related to resistance in P. xylostella in the state of Pernambuco (Brazil), but there is currently no i...

This bulletin describes plant protection in Taiwan, systems of farmer education and the monitoring of produce for pesticide residues. It describes the results of experiments to test the exposure of farmers to chemical pesticides during application, and the toxicity which resulted. It also discusses various tests of pesticide resistance among pest populations, using GPS and GIS. Resistance manag...

The development of pest resistance to transgenic crop plants producing insecticidal toxins from Bacillus thuringiensis Berliner (Bt) poses a major threat to their sustainable use in agriculture. "Pyramiding" two toxins with different modes of actions in the same plant is now being used to delay the evolution of resistance in the insects, but this strategy could fail if a single gene in a pest c...